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STANDARD OPERATING PROCEDURE Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers DEQ03-LAB-0027-SOP Version 2.0 June 27, 2003 Laboratory Division 1712 SW 11th Avenue Portland, OR 97201 Phone: (503) 229-5983 Fax: (503) 229-6924 www.deq.state.or.us Prepared by: Sarah Bennie and Ben Jones ________________ Date: _____________________ Reviewed by: _______________________________________ Date: _____________________ Technical Director Approved by: _______________________________________ Date: _____________________ June 2003 Quality Assurance Officer This page left intentionally blank. Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 3 of 25 Table of Contents Table of Contents ............................................................................................................................ 3 1. Test Method ............................................................................................................................ 4 2. Applicable Matrices................................................................................................................. 4 3. Detection Limits ...................................................................................................................... 4 4. Scope and Application ............................................................................................................ 4 5. Summary................................................................................................................................. 4 6. Definitions ............................................................................................................................... 4 7. Interferences ........................................................................................................................... 6 8. Safety ...................................................................................................................................... 8 9. Equipment and Supplies ......................................................................................................... 8 10. Reagents ............................................................................................................................ 9 11. Standards ........................................................................................................................... 9 12. Sample Collection, Preservation, Shipment, and Storage ................................................. 9 13. Calibration and Standardization ......................................................................................... 9 14. Quality Control .................................................................................................................. 10 14.1. Data Assessment and QC Acceptance Criteria ........................................................... 10 14.2. Corrective Actions for Out-of-control Data ................................................................... 10 14.3. Contingencies for Handling Out-of-control Data .......................................................... 11 15. Procedure ......................................................................................................................... 12 15.1. Pre-sampling conditioning:........................................................................................... 12 15.2. Pre-sampling weighing:................................................................................................ 12 15.3. Post-sampling conditioning: ......................................................................................... 14 15.4. Post-sampling weighing: .............................................................................................. 14 16. Calculations ...................................................................................................................... 15 17. Method Performance ........................................................................................................ 16 18. Maintenance ..................................................................................................................... 17 19. Pollution Prevention.......................................................................................................... 19 20. Waste Management ......................................................................................................... 19 21. References ....................................................................................................................... 19 Appendix A: Calibration of Working Mass Standards.................................................................... 20 Appendix B: Criteria Tables for PM2.5 FRM Sampling ................................................................ 23 Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 4 of 25 1. Test Method Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers 2. Applicable Matrices This method applies to the analysis of ambient air particulate collected on 47mm diameter Teflon filters. 3. Detection Limits Based on the Partisol field blanks statistics, we have estimated the method detection limit at 0.6 µg/M3, assuming a volume of 24M3 per sample We are also using 0.6 µg/M3 as our method reporting limit. Because EPA has requested that the results of speciation sampling be uncensored, we have not applied a reporting limit to the SASS results. If we use the Partisol field blanks statistics for the SASS sampler, the MDL would be 2.1 ug/M3 , assuming a volume of 9.7M3 per sample. 4. Scope and Application This method describes the gravimetric analysis of ambient air particulate samples collected on 47mm Teflon filters. This method is specifically applicable to samples collected using either an R&P Partisol sampler or a MetOne SASS sampler. The R&P Partisol sampler has been used as the Federal Reference Method (FRM) sampler for the PM2.5 program, although it can also be used for PM10 sampling.. The MetOne SASS sampler has been used for the Speciation program within the PM2.5 program. This procedure also describes the calculation of the particulate mass per volume of sampled air, using both the laboratory gravimetric data and the field sampling data. Although the sampling SOPs are described else where, the laboratory personnel must be familiar with the sampling requirements. The method complies with the national ambient air quality standards referred to as PM2.5, as described in Appendix L of 40 CFR, Part 50. 5. Summary An electrically powered air sampler draws ambient air at a constant volumetric flow rate into specially designed inertial particle-size separator (e.g, cyclones or impactors) where the suspended particulate matter in the PM2.5 or PM10 size ranges is separated for collection on a polytetrafluoroethylene (PTFE) filter over a specified sampling period. Each filter is weighed before and after sample collection to determine the net gain due to the particulate matter. The mass concentration in the ambient air is computed as the total mass of collected particles in the PM2.5 or the PM10 size ranges divided by the actual volume of air sampled, and is expressed in µg/m3 at LTP (local temperature and pressure) 6. Definitions Batch: environmental samples that are prepared and/or analyzed together with the same process and personnel, using the same lot(s) of reagents. Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 5 of 25 Analytical batch is composed of prepared environmental samples (extracts, digestates or concentrates) which are analyzed together as a group. An analytical batch can include prepared samples originating from various environmental matrices. Blank: a sample that has not been exposed to the analyzed sample stream in order to monitor contamination during sampling, transport, storage or analysis. The blank is subjected to the usual analytical and measurement process to establish a zero baseline or background value and is sometimes used to adjust or correct routine analytical results. Lab Blanks: These are filters that are conditioned, pre-sample weighed, stored in labeled Petri dishes in the laboratory, reconditioned, and then reweighed along with post- sample filters. They are weighed with the similarly numbered post-sample (or loaded) filters at regular intervals (rather than all at one time). Field Blanks: These are filters that are treated in all ways as a normal sample (including installation on the samplers in the field) except that no air is sampled onto them. (Field blanks, as defined in this SOP, are referred to as “transfer blanks” in LIMS.) Calibration: to determine, by measurement or comparison with a standard, the correct value of each scale reading on a meter, instrument, or other device. The levels of the applied calibration standard should bracket the range of planned or expected sample measurements. Continuing Calibration Blank (CCB): a “zero” standard analyzed along with the CCV standard. The CCB verifies that the lower end of the calibration curve remains valid during the analysis of the batch of samples. A CCB is analyzed at the beginning of each batch, at the end of a batch, and at least every 10 samples during a batch. For this SOP, the CCB is the balance reading when nothing is placed on the balance pan. Continuing Calibration Verification Standard (CCV): a standard analyzed after the initial calibration to verify that the instrument calibration remains valid. A CCV is analyzed at the beginning of each batch, at the end of a batch, and at least every 10 samples during a batch. For this SOP, the CCV is the 200 mg working standard. Control filter: A control filter is weighed at the beginning of each weighing session. One filter is chosen at random at the beginning of every new filter lot. The filter is weighed, it is placed in an air-permeable Petri dish that is stored in the weighing room. The Petri dish is labeled with the filter’s weight, the filter’s ID, the date, and the lot number. The control filter is used to monitor any significant changes in the control room’s environment that may affect the filters. Holding Times (Maximum Allowable Holding Times): the maximum times that samples may be held prior to analysis and still be considered valid or not compromised. Laboratory Control Sample (LCS): a sample matrix, free from the analytes of interest, spiked with verified known amounts of analytes or a material containing known and verified amounts of analytes. It is generally used to establish intra-laboratory or analyst specific precision and bias or to assess the performance of all or a portion of the measurement system. For this SOP, the LCS is equivalent to the QCS. Laboratory Duplicate: aliquots of a sample taken from the same container under laboratory conditions and processed and analyzed independently. For this SOP, aliquots cannot be taken from a single filter. As an alternative, we reweigh 1 out of 10 filters and refer to it as a laboratory duplicate, a reweigh duplicate, or a reweigh. Laboratory Information Management System (LIMS): a comprehensive computerized database system that a laboratory uses for sample tracking and data management, from sample receipt to reporting and archiving. Matrix (Quality System): the component or substrate that contains the analyte of interest. Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 6 of 25 For this analysis, the matrix is ambient air particulate, which is really neither “air and emissions” or “solids”, the most relevant NELAC matrices. For the purposes of batch and QC requirement determinations, this is the only matrix (although particulate size can affect the results in some cases). Matrix Spike (spiked sample or fortified sample): a sample prepared by adding a known mass of target analyte to a specified amount of matrix sample for which an independent estimate of target analyte concentration is available. Matrix spikes are used, for example, to determine the effect of the matrix on a method's recovery efficiency. For this SOP, we have no reliable method of spiking the samples. Method Detection Limit (MDL): the minimum concentration of an analyte that can be identified, measured, and reported with 99% confidence that the analyte concentration is greater than zero. Particulate matter: A generic term for a broad class of chemically and physically diverse substances that exist in the air as discrete particles (liquid droplets or solids) over a wide range of sizes. Quality Control Sample (QCS): an uncontaminated sample matrix spiked with known amounts of analytes from a source independent from the calibration standards. It is generally used to establish intra-laboratory or analyst specific precision and bias or to assess the performance of all or a portion of the measurement system. For this SOP, the 100 mg mass standard acts as the QCS. Quantitation Limits: levels, concentrations, or quantities of a target variable (e.g., target analyte) that can be reported at a specified degree of confidence. Replicate Analyses: the measurements of the variable of interest performed identically on two or more sub-samples of the same sample within a short time interval. For this SOP, replicate analysis is performed on samples (also referred to as field duplicates) collected at the same site and the same time, using the same model of sampling equipment. The duplicate samples are collected with either a collocated sampler (MV or Partisol sampler) or another channel of the same sampler (SASS Speciation sampler). Standardized Reference Material (SRM): a certified reference material produced by the U.S. National Institute of Standards and Technology or other equivalent organization and characterized for absolute content, independent of analytical method. For this method, our primary mass standards masses are NIST traceable. 7. Interferences Because these filters may be analyzed to determine the particulate’s chemical composition, interferences are not limited to interferences that have a significant effect on the mass. Any contamination or material loss will have a greater effect on some chemical species than it will have on the mass. Analysts should keep this in mind during all processes involving the filters. The following are specific interference that may affect mass, sample composition, or both: 1) Both the filter material and the loaded particulate can absorb moisture. Teflon filters gain less than 4 µg of weight with every 10% increase in relative humidity. Depending on the weight and composition of the particulate, the absorbed moisture on the particulate may be much greater than the absorbed moisture on the filter membrane. High moisture may also affect chemical reactions leading to volatilization of inorganic salts. To correct for humidity differences, a controlled environment with the RH at 32.5% +/- 2% is used for equilibrating (≥ 24 hours) and weighing all of the filters. 2) Temperature variations in the weighing room can result in balance instability as the balance is sensitive to temperature and air density changes. The particulate itself is also sensitive to Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 7 of 25 temperature as volatilization can occur at different rates at different temperatures. Maintaining the temperature at 21.5° C +/- 0.5° C is sufficient to minimize adverse temperature effects. 3) Vibrations may result in balance readout instability. The use of a balance table of high mass with vibration-isolating pads reduces the effects of building or room vibrations. Vibration producing instruments, such as fans or audio speakers, should not be in contact with the balance table. Infrequently, machinery or construction in or outside the building may lead to episodes of balance instability. 4) Static electricity can interfere in two ways: a) If static has built-up on the filters or nearby objects, it can cause balance inaccuracies. The balance may be slow to reach a stable weight and lab duplicates (and field duplicates) may be out of control. b) Static electricity that is present on filters or their containers may cause transfer of particulate from and/or to the filter surface. The buildup of static charge can be reduced by grounding conductive materials, applying anti- static solutions to non-conductive surfaces (i.e., inside of balance chamber), avoiding air currents blowing directly onto plastic surfaces, wearing low-static clothing, and using a grounding pad for the operator to touch prior to and during filter weighing. The most important measure taken in this method is the use of Staticmaster strips to reduce static on the filters both before and during weighing. Exposure to the Staticmaster strips for 30 seconds prior to weighing is sufficient to reduce the charge on the filters under normal circumstances. A Staticmaster strip is also placed in the weighing chamber. The Staticmaster strips have a limited lifetime (due to the 138 day half-life of Polonium 210) and are replaced every 6 to 9 months. 5) Touching the mass standards, filters, and filter handling equipment can contaminate them with oils, perspiration, and cosmetic products. Handling filters only with the appropriate forceps can eliminate contaminants. 6) The cassettes that hold the filters during sampling can add to the weight of the filters. The originally supplied white cassettes off-gassed or exuded organic compounds that increased the mass of the filters. We have found that thorough cleaning (including hot water, detergent, and sonic treatment) can reduce this contamination. This does not seem to be a problem with the newer blue cassettes, although an initial thorough cleaning of them is still necessary. 7) Dust can contaminate filters at any stage of handling. Cleaning the work area and keeping filters in protective containers help reduce dust contamination. All items used in the weighing room (e.g. furniture, paper, trays, cleaning equipment) should be considered to be sources of dust and efforts should be made to reduce their contribution. The controlled room air supply is filtered to reduce particulate circulation in the room. New analysts are encouraged to weigh dust, sand and small fibers to get a sense for how much these contaminants weigh. 8) Chemical vapors can change the weight and composition of the collected particulate in several ways. Particulate can absorb organic vapors, including plant generated volatiles (i.e., terpenes), combustion products (i.e., vehicle fumes), or laboratory reagents (e.g. solvents). Air particulate can also react with gases, particularly ammonia (which is present in human breath and laboratory reagents). 9) Power supply or grounding fluctuations and equipment operations inside or outside of the building can also cause possible balance instability. We have not found this to be a problem at our current facility. Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 8 of 25 8. Safety For general laboratory safety procedures, consult the DEQ Laboratory Safety Manual (Chemical Hygiene Plan). Refer to the Job Hazard Assessment for this procedure (Particulate Matter Weighing) and conduct analysis in accordance with the safety precautions specified. Material Safety Data Sheets (MSDS) are available in the laboratory library. 9. Equipment and Supplies • AQLIMS database and associated VB programs for capturing weights from balance and performing calculations. • Cassette opening tool • Computer. The computer is configured to capture the weights from the balance and store them in a database table used by AQLIMS. • Filter cassettes, consisting of three parts: a top, bottom, and screen, as supplied by R & P. These cassettes meet the requirements as stated in section 7.3.5 of Appendix L to 40 CFR Part 50, except they have beveled edges as required for the R&P Partisol samplers. • Filter labels, vinyl, pre-numbered, that fit in the groove on the edge of the cassettes • Forceps, non-magnetic, stainless steel, non-serrated • Forceps, plastic-tipped • In-line filter installed on the line attached to the building compressed air, Balson Filter Tube, Grade BQ • Kimwipes • Light box used to examine filters for pin holes. • Lighted magnifier used for examining the filters for damage or contamination. • Mass standards: Primary standards are 100 and 200 mg ASTM class 1 weights that are NVLAP certified annually. Working standards are 100 and 200 mg weights that are compared to the Primary standards quarterly. • Microbalance, ATI-Cahn C44. The autozero and self-calibration features should be disabled. • Petri dishes, polystyrene, 50x9 mm, Falcon. • Post-sampling conditioning trays, fabricated by staff • Protective boxes for shipping and temporary storage of filters while they are in the filters cassettes, 2 5/8'”square by 5/8" high molded, hinged clear styrene • Refrigerator maintained at <4°C. • Slide trays, Leica 4G002 (Pro Photo Supply by special order). • Static dissipating pad surrounding the balance. • Staticmaster anti-static strip (1U400) installed in the weighing chamber of the balance. • Staticmaster anti-static strips (2U500) mounted the top and bottom of plastic stand. • Teflon filters, 46.2 mm, as supplied by EPA. These filters meet the requirements as stated in section 6.0 of Appendix L to 40 CFR Part 50. These have a nominal pore size of 2 um (based on water filtering) but collect greater than 99.7% of the 0.3 um particles based on air filtering. • Temperature and relative humidity sensor and controller, Humiscan (General Eastern) with accuracies of ±0.2°C, and ±1% RH. Associated with this device is a data logger and software to download the logged data. • Temperature and relative humidity sensor and recorder, Dickson THDx with accuracies of ±1°C, and ±2% RH. • Ultrasonic bath. Sonicore Model 211 TH, or similar. • Weighing room, controlled for temperature and RH using a Honeywell Digital Controller (UDC 3300), a Munters desiccant wheel dehumidifier (HC-300-EA), the building steam supply, and a Copco installed furnace/air-conditioner unit. The temperature and relative humidity of the room Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 9 of 25 is recorded continuously. Either a chart paper record (from the Dickson THdx meter) or a data file (from the Humiscan datalogger) is retained as a record of the room’s conditions. • Weighing table, 3 point Gibraltar stone table. • Working mass standards, 100 and 200 mg weights that are compared to the primary standards quarterly. 10. Reagents • Micro detergent 11. Standards The balance is calibrated using an internal mass standard. This calibration is confirmed daily using the “working” 100 and 200 mg working standards, which are calibrated to the primary standards every three months (See “Appendix A”). 12. Sample Collection, Preservation, Shipment, and Storage There are slight differences in the handling procedures for SASS Speciation samples and for Partisol samples. It is primarily the Partisol procedures that are described below. See the Speciation Sampling Canister Processing SOP to learn the differences for the SASS Speciation samples. Clear, polystyrene plastic protective cases are used for sample retrieval, shipment, and storage of the Partisol sampler samples. These hold individual filters within their sampling cassettes and are taped shut prior to sampling. Samples are collected from the samplers by field staff, at which time they are stored in either a cooler or an on-site refrigerator. Samples are retrieved from the samplers within 177 hours of the end of sampling for Partisol FRM PM2.5 samples (48 hours for SASS Speciation samples). Any abnormalities that are observed on the filters, the sampler, or the nearby environment are noted on the appropriate field sheet. During shipping or transport, the samples are kept at <4˚C. Upon return to the laboratory, the samples are placed in a refrigerator maintained at ≤ 4˚C. To equilibrate the filters, they are taken to the weighing room, removed from their protective cases and equilibrated in their cassettes for a minimum of 24 hours before post-sampling weighing. The holding time for pre-sampling (tared) filters is 30 days, although the results are not downgraded if this holding time is exceeded. The holding time for post-sampling (loaded) filters is 10 days, unless they are maintained ≤ 4˚C during the entire time between retrieval and the start of conditioning, in which case the time period cannot be more than 30 days. (The latter option was modified by EPA slightly by memo dated March 1, 2002 stating that the holding time can be calculated at 34 days minus the average temperature—degrees C—during transport and post- sampling storage—but not more than 30 days.) After post-sampling (loaded) weighing, filters are stored in labeled Petri dishes and cataloged in closed cardboard boxes. They are stored in either a refrigerator or freezer for an archiving period of at least one year. 13. Calibration and Standardization Calibration of the balance prior to weighing is covered under “Section 15, Procedure”. Calibration of the working mass standards occurs every three months, and is covered in “Appendix A”. Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 10 of 25 14. Quality Control 14.1. Data Assessment and QC Acceptance Criteria Data assessment and QC acceptance criteria are of primary importance in assessing the quality of data resulting from an analytical batch. Both negative and positive biases are a concern. The following data assessment and QC data are required for all analyses: Listing of required Quality Control (QC) elements, including frequency and acceptance limits. Quality Control Element Frequency Acceptance Limits Quality control sample 1 at the beginning of each ± 3µg (QCS)—100mg working batch mass standard Continuing Calibration 1 per 10 samples ± 3µg Blank (or CCB)—empty balance pan Continuing Calibration 1 per 10 samples. ± 3µg Verification (CCV)—200mg working mass standard Field blanks All sites, at a frequency of Between -10µg to +20µg approximately 5% Lab blanks At least 1 per 20 samples, or ≤ ±10µg/filter one every batch. Laboratory duplicates-- 1 in every 10 samples ≤ ±7µg/filter. reweighs Control filter 1 at beginning of batch ≤ ± 5µg/filter change from the last weighing session. Weighing room temperature Check record for the 24 hours 21.5°C ± 0.5°C prior to weighing Weighing room relative Check record for the 24 hours 32.5% ± 2%. humidity prior to weighing 14.2. Corrective Actions for Out-of-control Data It is at the analyst’s discretion on how to handle out-of-control or unacceptable data. Quality control measures and corrective actions are as follows: 1) QCS: If the initial weighing of the 100 mg mass standard is out-of-control, re-tare and re- calibrate the instrument and weigh the 100 mg mass again. If it is still out of control, inform the senior chemist. Together, the analyst and the senior chemist may investigate by checking for balance stability, confirming the weight of the standard relative to the primary standards, performing a balance corner-check (see appendix A) or contacting a balance technician to make repairs. Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 11 of 25 2) CCB: If the CCB is out of control, the balance can be retared (which will automatically bring the CCB in-control) after investigating that the balance pan is clean. If the CCV is then in-control, then the filters weighed since the last in-control CCB should be reweighed. The CCB can be checked frequently during the weighing session, and if it is in-control but off slightly, the balance can be retared. If the CCB is out of control more than once during a weighing session, discuss and investigate the instability with the senior chemist. 3) CCV: If the CCV is out of control, the balance can be retared and recalibrated. If the CCV is still out of control, the same actions should be taken as stated under the QCS. Whenever the CCV is found to be out of control, all filters weighed after the last in-control CCV should be reweighed. 4) Field blanks: If any field blank has a weight change that falls outside the control limits, investigate the weighing process by repeating the post-sampling weighing and verifying that the pre-weighing data in the database is correct. If the field blank data is still out of control, inform the senior chemist. Further investigation may include investigating the contribution to the blank in the various steps of sample collection, transport, and processing. 5) Lab blanks: Investigate by reweighing both the lab blank in question and any additional lab blanks within the session, and by checking the calibration of the balance. If the post- sampling weighing is out of control for only the one lab blank, inform the senior chemist, but continue weighing the post-sampling filters. If the investigation concludes that the out of control condition is more widespread, the problem must be resolved before weighing may continue. 6) Laboratory duplicates or reweighs: If a replicate weighing exceeds the established control limit, investigate the source of the poor precision. Gently clean the weighing pan with a photographer’s brush that is located near the balance. Re-weigh the other nine filters from the duplicate’s original set. Inform the senior chemist if the problem cannot be resolved. 7) Control filter: If the control filter’s weight is significantly different from previous weighings, investigate and correct the problem before proceeding. Needed corrections may include cleaning the balance pan, re-zeroing and recalibrating the instrument, checking for sources of balance instability, and examining the filter for contamination. If a solution cannot be found, inform the senior chemist and investigate further, including the confirmation that the room did not become out-of-control since the previous weighing session. 8) Weighing room temperature and humidity control: Inform the senior chemist if the room is out-of-control, and investigate the reason for the room’s instability. (The PM2.5 rule actually only requires that the room be controlled to between of mean relative humidity of between 30% and 40% with a variability of not more than 5% within 24 hours, and a mean temperature of between 20°C and 23°C with a variability of not more than 2°C within 24 hours. If these less stringent measures are the met, the senior chemist may judge that the conditions are in-control, and weighing may continue.) The accuracy of the system sensors may need to be investigated. Shut down and restart the room’s systems according to the chart on the door. HVAC professionals may be employed to improve the operation of the environmental controls. 14.3. Contingencies for Handling Out-of-control Data If none of the corrective actions brings the QC elements under control, the data may be reported as estimates or not reported at all, as decided by the analyst and the section Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 12 of 25 manager. 15. Procedure 15.1. Pre-sampling conditioning: 1) Inspect the filters for flaws using EPA’s guidelines. Use the non-serrated stainless steel forceps (as in all filter handling) and a lightbox for backlighting. Filters are inspected and conditioned by box number. Perform these inspections in the conditioning room. Record approximate percentages of faults and discard rejected filters. Inform the EPA if the number of rejects is excessive compared to their testing results. The list of EPA defined flaws include: • Pinholes • Separation of ring • Chaff or flashing (extra attached residual material on the ring which would prevent airtight sealing in the cassette.) • Loose material • Discoloration • Filter non-uniformity • Other imperfections 2) Place the filters in slide trays, maintaining all ring IDs facing left. 3) Gently blow the filters clean using the compressed air line with the in-line grade BQ filter (in room U51). This step removes loose pieces of filter membrane or filter rings that may have contaminated the filters during manufacturing. 4) Immediately return the filters to the weighing room and condition them for a minimum of one week. (If it is determined that a lot requires more than a week for initial equilibration, this period of time should be extended.) Label each tray with the lot number, box number, analyst’s initials, and the date that conditioning began. Place the loaded slide trays into their holding boxes, leaving the box doors open. 15.2. Pre-sampling weighing: This describes the process for Partisol sampler filters. The MetOne sampler filters are processed similarly but they are loaded in the canisters prior to being taken to the field. See the Speciation Sampling Canister Processing SOP to learn the differences for the SASS Speciation samples. Note: Upon initially opening the weighing program, several choices and inputs are required. The analyst must be trained on using this software, but each computer input will not be discussed here. 1) Record in a blue book and in the LIMS system the following data: analyst’s initials, date, time, balance ID, relative humidity, and temperature. At the start of a new slide tray, tape the label with the conditioning information in the blue book. 2) Determine whether the temperature and relative humidity in the conditioning room has been 21.5°± 0.5°C and 32.5%± 2.0%, respectively, for the previous 24 hours. This may involve visually reviewing the chart or it may mean performing calculations based on data files stored in the computer. If the requirements are met, continue weighing. If not, investigate why and take corrective action according to the quality control methods Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 13 of 25 described in “Section 14, Quality Control”. In addition, during the weighing session, confirm every ten filters that the room remains under the controlled conditions. 3) Open the door to the balance chamber momentarily, and then close it. Tare the instrument after the reading becomes steady, then perform a balance calibration (i.e. push the calibration button). Check the balance’s tare again. If the tare is 0.000 µg, continue. If it is ≤ ±0.002 µg, re-tare and continue. If it is > ±0.002 µg, re-tare and recalibrate. If the balance needs to be recalibrated more than once at this point, it is not stable enough to continue weighing, and the source of the instability needs to be investigated. 4) Weigh the 100 mg and 200 mg working mass standards, using the plastic forceps to handle them. If they are not within ± 3 µg, investigate and take corrective action (see “Section 14, Quality Control”). Record these weights in the blue book. 5) Weigh the control filter (see “Section 14, Quality Control”). If the weight change from the previous weighing exceeds ± 5 µg, check the balance tare, the mass standards, and recalibrate if necessary. 6) Visually inspect the filter for any defects or signs of contamination. Discard the filter if defects are noted. If a single particle or fiber is noted as a contaminated, gently remove it from the filter by gently tapping the back of the filter against the edge of the Staticmaster assembly. 7) Place the filter on the Staticmaster strip outside the balance. The filter should remain on the strip for at least 30 seconds. 8) Enter the filter ID number in the computer and in the logbook. 9) Move the filter from the Staticmaster strip to the balance pan. Close the door and allow the readout to become stable (remain unchanged for 20 seconds). Capture the weight in the LIMS program and record the weight in the blue book. Occasionally, the last digit of the display will alternate between 2 numbers. If this continues for 30 seconds or more, it is because the filter mass is approximately midpoint between the two displayed values. Accept the last value displayed at ~30 seconds. 10) Place the filter in a clean cassette and press the top half into the bottom half at several points along the edge to securely close the cassette. (Filters must always be placed in the cassettes with the ring ID facing up, away from the screen. This allows us to know which side is loaded with particulate even if the loading is very light.) Attempt to rotate the two portions of the ring. If the portions rotate, reassemble the cassette using a different set of rings. (Note, with age, the cassette rings may crack. If cassette rings snap together too loosely, look for cracks in the bottom ring. Discard any cracked rings.) 11) Place the filter ID number label on the edge of the cassette. The label may need to be trimmed with scissors to allow the label to fit in the recess on the edge of the cassette. If trimming is required, ensure that the number is still legible. (The label may cause jamming in the sampler if the label’s edges protrude beyond the recessed groove on the cassette’s edge.) 12) Place the cassette in a clean, individual shipping case. 13) Repeat the weighing process with additional filters. 14) After weighing 5 filters, check the balance’s tare. This is the continuing calibration blank (CCB). See “Section 6, Definitions” for a definition and “Section 14, Quality Control” for control limits and corrective actions. 15) After weighing 10 filters, record the temperature and relative humidity of the conditioning room. Check the balance’s tare (CCB). Perform the necessary control actions and then Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 14 of 25 check the 200 mg mass standard. This is the continuing calibration verification (CCV). See “Section 6, Definitions” for a definition and “Section 14, Quality Control” for control limits and corrective actions. 16) Randomly select one of the previously weighed ten filters, remove it from the cassette, and reweigh. This is the lab duplicate or “reweigh”. See “Section 6, Definitions” for a definition and “Section 14, Quality Control” for control limits and corrective actions. 17) During each weighing session, place at least one per 20 (but no fewer than 1) of the weighed filters directly into a Petri dish and set it aside to be used as a laboratory blank (see sections 6 and 14). A corresponding filter ID label should be placed on the lab blank container and the Petri dish marked with the date, the term “Lab Blank”, and the analyst’s initials. 18) At the end of each weighing session, record the balance’s tare, the time, the temperature, the relative humidity, and the 200 mg working standard weight. 19) Following weighing, the filter shipping boxes should be labeled with the filter expiration date (30 days from the initial weighing), and taped shut with masking tape. Place filters that are ready for sampling in the designated area in the laboratory. The laboratory staff is responsible for ensuring that an appropriate number of filters are available for the monitoring staff. Extra filters (relative to the number of filters that will be used within the next few weeks) should not be weighed. This will minimize the number of filters that are discarded because they are not used before their expiration date. 20) Print out a report of the weights captured during the weighing session and check the entries against the records in the blue book. If any errors were made, investigate further and have the senior chemist correct any erroneous records. The printed reports should be stored as a backup record of the weights captured by the database. 15.3. Post-sampling conditioning: Because filters “expire” after being sampled, and because some filters will be returned to the laboratory close to their expiration date, the check-in refrigerator must be checked at least twice a week (preferably Monday AM and Thursday AM) so that filters can be transferred to the control room and weighed 1) Retrieve the filters that the monitoring staff have checked-in and placed in the refrigerator. In the conditioning room, remove the cassettes from the shipping cases and place the cassettes in the conditioning trays in numerical order. Mark each tray with the date and time that the conditioning began. 2) At the same time, open a Petri dish of one lab blank for every 20 filters (or at least one per weighing session for smaller batches), and arrange it in numerical order with the samples. Condition the lab blank(s) alongside the post-sampling filters. Condition all filters for at least 24 hours with the room conditions in-control. 15.4. Post-sampling weighing: For the post-sampling weighing, follow the same steps as the pre-sampling weighing except: 1) Weigh the post-sampling filters as soon as possible after the 24 hour conditioning period. 2) After weighing the mass standards, weigh the lab blank(s) and capture the weight normally. See Section 14 for the control limits and the corrective actions. Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 15 of 25 3) When removing the filters from the cassettes, use the specially designed tool to separate the rings of the cassettes. 4) Immediately before post-sampling weighing, inspect each filter for damage or any unusual appearance. This may include tears in the filter, unevenness of the loading pattern, pin holes, inappropriate sized particulate, and liquid droplets. Make a comment in both LIMS and in the blue book of any damage or unusual appearance. If large particles--such as insect body parts--are present, carefully remove and add a comment in LIMS and in the blue book. When damage appears to have originated in the field, include a description of the damage in the LIMS and bluebook but also ask the senior chemist to communicate the problem to the monitoring staff. 5) After each filter is weighed, place it in a Petri dish onto which the corresponding ID label has been transferred. 6) One filter from each set of 10 is set aside and reweighed as a lab duplicate or reweigh. See Section 14 for control limits and corrective actions. 7) At the end of each weighing session, immediately transfer all post-weighed filters to the archiving refrigerator. 16. Calculations LIMS will perform the calculations based on the data from the monitoring staff and the inorganic staff. The equation is: 1000(Mpost – Mpre) C µg/m3 = ------------------------ Va where Cµg/m3 = ambient particulate concentration in µg/m3 Mpost = post-sampling filter weight in mg Mpre = pre-sampling filter weight in mg Va = sampled air volume in ambient m3 If the sampling period is less than 1380 minutes, the concentration may need to be calculated as stated in Section 3.3 of Appendix L to Part 50: “ . . . However, when a sample period is less than 1,380 minutes, the measured concentration (as determined by the collected PM2.5 mass divided by the actual sampled air volume), multiplied by the actual number of minutes in the sample period and divided by 1,440 minutes may be used as if it were a valid concentration measurement for the specific purpose of determining a violation of the NAAQS....” To perform these calculations, both the field data and filter weights must be recorded in the appropriate database tables. The filter weights are captured directly from the balance as described in the Procedure section of this SOP. Recording the field data in the data base includes both importing data files from the samplers and hand entering information that is recorded on the field sheets. Both the monitoring staff and the lab staff are involved in populating the field data tables and in evaluating the validity of the results. The results are reported with “grades” that convey the validity of the results. Validation criteria are defined in a series of tables (see Appendix B: Criteria Tables for PM2.5 FRM Sampling.) The grades are as follows: Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 16 of 25 A = Valid (“A+” if valid results were generated by DEQ Laboratory) B = Estimate, with comments C = Invalid, with comments D = No sample, with comments The data reports also need to include any appropriate EPA flags that should be associated with the data in the AIRS (or AQS) system. Because we transfer only “A” data to EPA, only valid quality data needs to have EPA flags, when appropriate. These flags can be extracted from the descriptive comments associated with each results, but our best means of communicating these flags is to include in the analysis comment the statement: “EPA flags: xx, yy”. The following are some of the flags that we have used in the past: Y = Short sample still yielding violation of NAAQS. W = Sampling flow rate was off the set point by >5% for >5 minutes. X = The filter temperature during sampling was different than the ambient temperature by >5° C for >30 minutes. DST = For speciation samples, the shipping temperature was out of specifications (>4°C). E = Forest fires in the area impacted the results. 6 = Data based on sampling or analysis prior to QAPP approval. Additional flags may be utilized as appropriate (see memo from R. Scheffe, on June 15, 2000). Besides the reports that organize the particulate matter results, several additional reports are generated to describe quality control information. For example, once a month the monitoring staff gives the lab staff a list of the previous month’s field blanks. The filter IDs are entered into AQLIMS, and a monthly field blank report is generated. The filter IDs of all lab blanks are also entered into AQLIMS, and a monthly lab blank report is generated. 17. Method Performance Based on the 2002 data, the average change (loaded weighing – tare weighing) in lab blanks’ weights is +0.0002 mg, with a standard deviation of 0.0029 mg. Based on the 2002 data, the average change (loaded weighing – tare weighing) in field blanks’ weights (Partisol samples only) is +0.0030 mg, with a standard deviation of 0.0039 mg. We have only participated in one round robin study for particulate matter gravimetric analysis. In that 1999 round robin study, several filters were weighed by 6 different laboratories. This involved repeatedly shipping filters between laboratories, and repeatedly weighing--at different laboratories--the same filters. This round robin study format created some biases due to the study process itself (i.e. the filters gained weight with time and continued handling.) Because of this bias, the round robin study may lead us to judge the method to be less precise than it actually is. Disregarding this limitation, one conclusion that can be drawn from the round robin report was that the “average” standard deviation of the results from all laboratories for any one filter is 0.0046 mg. Oregon DEQ results were biased 0.0024mg per filter lower than the overall averages, with a standard deviation of bias equal to 0.0014 mg per filter. Therefore, Oregon DEQ results were well within the acceptable range, although the fact that Oregon DEQ received the filters in the middle of the study (4th out of 7) probably helped our apparent performance in the study. Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 17 of 25 18. Maintenance 1) Weekly cleaning of area and equipment: The balance chamber is cleaned weekly with a fine brush. In addition, the pan is cleaned whenever particles are visible or a sudden change in the instrument tare occurs. Staticmasters are cleaned every week at the same time as the balance chamber. They can be cleaned with a puff of canned, pressurized air. The tables, floor, and all dust-catching surfaces in the room are cleaned weekly with a moist towel. This should occur when the room will not be used for several hours (for example, on Friday afternoon.) Vacuuming the room should also be avoided, unless a HEPA filter vacuum is used. 2) Preventative actions to reduce dust contamination of equipment and weighing area: To reduce dust contamination in the balance chamber, the door is kept closed except when the balance is in use. Inspect the HVAC filters (FARR 30) annually. Replace if they are heavily loaded. One filter is located behind the return air vent on the east wall of room, near the floor. The other is located under the refrigerant unit in the utility closet. Keep the room door closed, and limit the traffic into the room. Minimize the amount of paper, supplies, and equipment that are brought into the room (and keep work spaces uncluttered to make cleaning easier.) In general, sources of dust and fibers should not be brought into the weighing room unless necessary. 3) Filter cassette cleaning: Filter cassettes and screens are cleaned when they are first purchased and subsequently after each use. (See “Section 7, Interferences” for a discussion of their initial cleaning.) The plastic rings of the cassettes are cleaned by washing them in a dishwasher at 60° C with a final rinse of RO water (all while in a mesh bag). Note: limit the number of rings per bag so that wash and rinse water reaches all rings in the batch. If the rings remain sticky (probably due to glue from the labels) after this cleaning, they can be cleaned with Scotch Brite scrubbers, Goo-Gone, or sharp scrapping tools. After this intensive cleaning, they need to be dishwasher washed again. The metal screens can easily capture fibers, so they are not exposed to fibrous material during cleaning or drying. They are placed in slide trays, soaked in hot water with a small amount of micro and then thoroughly rinsed with tap water followed by DI water. Rings should only be handled on outside edges (where they will not touch the filters) and the screens should only be handled with stainless steel forceps. After cleaning, the cassette parts are dried in the weighing room. Once dry, they should be stored in closed plastic boxes to keep them clean. 4) Shipping container cleaning: After each use, remove all tape from the used shipping boxes, and clean them with a Kimwipe that is moistened with DI water. The cases should be kept closed as much as possible so that they remain clean. When the containers become cracked, heavily scratched, or have excessive tape on their surfaces, they should be discarded. 5) Staticmaster strips replacement: Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 18 of 25 Staticmasters are replaced every six to nine months. The date of manufacture is stamped on each strip. ODEQ’s working expiration date for strips is 9 months to a year from the date of manufacture. Old strips are returned to the manufacturer. 6) Mass reference standards maintenance: The mass standards must be handled only with plastic forceps reserved for this purpose. The tips of the forceps are cleaned with alcohol and a lint-free wipe. The mass standards are stored in closed boxes. The working standards are kept next to the balance. The primary standards are stored in a dessicator cabinet. Primary mass standards are NVLAP certified once a year and the working standards are checked against the primary standards every three months (see Appendix A: Calibration of Working Mass Standards). The comparison consists of performing at least five weighing of each working and primary standard, with balance re-zeroing and recalibration between each set. If the standard deviation of any of the mass standards is greater than 2µg, the weighings are repeated. The updated working weights for the working mass standards are then assigned based on these comparisons. The mass standard storage boxes are labeled with the date of the last certification (for primary standards) or calibration (for working standards). 7) Balance settings: Once the balance features are setup correctly, do not change the settings. The balance can be programmed to control a variety of features. Most features are set to the defaults except the following: Allow handshaking with computer: code 5-4-1 Print continuously on stability: code 6-1-5 Very unstable conditions: code 1-1-4 Stability at 0.25 digits: code 1-3-1 Long delay: code 1-4-3 Auto-zero off: code 1-6-2 Auto-calibration off: code 1-15-1 Any changes to these settings should be discussed with the senior chemist. Access to the balance programming is locked to prevent any accidental changes from occurring. 8) Dehumidifier maintenance: Two filters in the Munters HC300 dehumidifier require cleaning annually or more frequently if any dusting operations occur in the storeroom where it is installed. See the operation manual for the filter locations. Clean the filters in the dishwasher or by rinsing with water. The dehumidifier should have additional preventive maintenance performed annually, as described in the operation manual. The maintenance includes checking the desiccant wheel, checking the air seals, and checking the outlet air temperature (120°F). Note: Past experience has been that when an acrid smell develops in the room, it is likely due to the desiccant wheel no longer rotating. A burned out motor or worn lower gasket could cause the desiccant wheel to stop rotating. 9) Temperature and Relative Humidity sensors maintenance: To maintain a record of the room conditions, the chart paper on the Dickson unit is replaced weekly and the Humiscan data logger file is downloaded to the shared directory approximately 3 times a week. The temperature and relative humidity sensors are calibrated or verified once a year. Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 19 of 25 19. Pollution Prevention There is no specific pollution prevention associated with this method. 20. Waste Management There is no specific waste management associated with this method. 21. References 1) Manuals for: Cahn C44 Microbalance. DicksonTHDx Temperature and Humidity Recorder. General Eastern Humiscan Industrial Humidity Transmitter. Honeywell UDC 3300 Universal Digital Controller. Munters Dehumidifier Model HC-300-EA. 2) US EPA (1997a) National Ambient Air Quality Standards for Particulate Matter-Final Rule; 40 CFR Part 50. Federal Register, 62(138):38651-38760; July 18, 1997. 3) US EPA (1997b) Revised Requirements for Designation of Reference and Equivalent Methods for PM2.5 and Ambient Air Quality Surveillance for Particulate Matter-Final Rule; 40 CFR Parts 53 & 58. Federal Register, 62(138):38763-38854; July 18, 1997. 4) US EPA Memo, David Mobley, on 1/19/2000 regarding filter cassette transport. Note: There are typos on the last page include the equation D=34●Tave, which should be D=34- Tave. (See http://www.epa.gov/ttn/amtic/files/ambient/pm25/pm25caset.pdf ) 5) US EPA Memo, Richard D. Scheffe, on 6/15/2000regarding use of AIRS flags. (See http://www.epa.gov/ttn/amtic/files/ambient/pm25/datamang/regions.pdf ) 6) US EPA Memo, David Mobley, on 3/1/2002 regarding PM2.5 filter retrieval from samplers. (See http://www.epa.gov/ttn/amtic/files/ambient/pm25/filtere.pdf ) 7) US EPA Quality Assurance Guidance Document 2.12: Monitoring PM2.5 in Ambient Air; Using Designated Reference or Class I Equivalent Methods; March, 1998. Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 20 of 25 Appendix A: Calibration of Working Mass Standards Scope and Application This method provides a procedure for calibrating working mass standards against primary mass standards to ensure that the working standards are assigned an accurate weight. This method is applicable to use on the Cahn C44 microbalance, located in the temperature and relative humidity room. The EPA Quality Assurance Handbook for PM2.5 suggests the recalibration of working mass standards every three to six months. Principle The calibration routine is completed using a double-substitution procedure in which a primary standard and the working standard are inter-compared to determine the average difference between the two weights. Errors that are introduced from internal calibration of the balance or in the balance indications are eliminated through the use of the balance alone as the source of mass comparison and by calibrating the balance over the range of use for the measurement. This procedure was developed from the Quality Assurance Guidance Document, Method Compendium PM2.5 Mass Weight Laboratory Standard Operating Procedures for the Performance Evaluation Program issued by the EPA in October 1998, which is turn was based on a version of SOP #4 in the NIST Handbook #145. Calibration weights Two primary mass standards (100 and 200 mg) are Troemner UltraClass weights that are NVLAP certified once a year: Nominal Serial Conventional Mass Uncertainty Tolerance Mass Number (mg) (mg) (mg) 200 16289 200.0021 0.0015 0.0050 100 16290 100.0012 0.0017 0.0050 The primary standards are stored in a closed desiccator, and are used only for calibrating the working standards or checking the accuracy of the balance. Working standards are used for routine filter weighing controls. These working standards are recalibrated against the primary standards on a three to six month schedule to identify any changes in weight due to regular handling. Below is a list of the working standards as of 02/03/99, but these are subject to change over time: Standard Filter Observed Mass Standard Deviation Mass Usage (mg) (mg) 100B FRM 99.9793 0.0008 T2 FRM 199.9762 0.0004 LE MV 199.9903 0.0004 200JE None 200.0140 0.0006 The working standards are stored adjacent to the balance for which they are primarily utilized. The mass standards are calibrated to the nearest microgram, therefore contamination of the weights and/or microbalance pan can affect the success of the calibration procedure. It is recommended that all potential sources of contamination be reduced or eliminated Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 21 of 25 prior to initiation of this procedure. Although the FRM room is designed to minimize sources of dust or other contamination, the analyst must utilize the utmost caution to minimize contamination of the standards or the microbalance. Oils from the skin will contaminate the standards if they were touched. If the standards are dropped, they should be cleaned with a brush and/or can-pressurized air, inspected under the stereoscope, and then recalibrated. The mass standards are always handled with the designated plastic or plastic tipped forceps. Metal forceps may scratch the mass standards. Procedure 1) Preliminary procedure Prior to conducting the mass calibration, inspect the mass standards using a low power stereoscope, record any defects (scratches, contamination) and, if needed, clean the standards with a brush, canned air, alcohol, or lint-free wipe. Clean the working area around the balance. Place the primary and working standards in the controlled weighing room near the balance. Allow the standards to attain thermal equilibrium with the room (i.e. wait at least 2 hours). Perform a balance corner check: A corner check is performed by placing a 5 gm working standard in the center of the balance pan and taring the balance after a stable reading is obtained. The mass is then placed at the approximate midpoint between the edge and center of the balance pan (a “corner”), and the weight is recorded after a stable reading is obtained. The mass is moved to the other three corners, and the weights are recorded. If the weight at any corner is greater than ±7µg, the balance is in need of service. Furthermore, the weights recorded at opposite corners should be equal, but opposite in sign. If the weights at opposite corners of the pan are of the same sign, this indicates that significant damage has occurred and substantial repairs to the balance may be required. If the corner checks indicate needed repairs, the senior particulate chemist is informed and further weighing is suspended until corrective action is taken. Corner checks are recorded in a laboratory blue book. 2) Balance Calibration Prior to initiating the mass calibration sequence, open the draft shield on the balance. Close the draft shield and tare the balance after it has stabilized. Then, calibrate the balance using the internal calibrations function (F1 key on the control unit). When the balance has finished calibrating, it will beep and display the current tare weight. If the tare weight is not 0.000 mg, tare the balance. The balance should be exercised prior to starting the mass calibration routine. Exercising involves completing a weighing series and verifying that the balance is operating properly. To exercise the balance, weigh each of the six mass standards in succession by opening the draft shield, placing the mass on the pan, and closing the draft shield. The weights should be placed in the weighing chamber using the standard non-metallic forceps. Place weights in the center of the pan. Record the observed mass after stabilization and verify that the balance stabilizes within approximately 20 seconds. The stabilization time for the mass standards is significantly less than that of the filters. The balance reading typically does not change after displaying “mg”. Following the weighing of the last mass, record the balance tare. If the tare has drifted more than ± 0.001 mg, recalibrate the balance, reweigh the sequence, and verify the drift. If the drift is still Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 22 of 25 greater than ± 0.001 mg, troubleshoot the balance. If the balance seems unsteady after the “balance exercising”, the mass standards calibration should be postponed until another day. 3) Mass Calibration Routine Tare and calibrate the balance. Weigh each of the masses in succession starting with the first mass and ending with the sixth mass in the sequence. Record each result in the blue book after the balance has stabilized. At the end of the sequence, check and record the balance tare. Zero the balance (even if the tare value is 0.000 mg), and calibrate the balance using the internal calibration routine (F1 on the control unit). After calibration, begin the second set of weighings in succession, starting with the sixth mass and ending with the first mass. After the completion of the second weighing, check the tare, zero the balance, and recalibrate. Continue this process until each mass has been weighed six times. The first mass weighed in each set should be incremented so that any instrument drift is normalized over the six sets of weighings. Check the results of the mass calibrations (see “calculations” below). If the calibration has been successfully completed, return the standards to their proper locations. 4) Calculations Transfer the calibration data from the laboratory blue book into an Excel worksheet. Calculate the mean and standard deviation for each of the weights. If the average test results for the primary mass standards do not indicate acceptable agreement (± 5µg) of the certified value, perform the following checks: repeat the process, check the primary standards for visible signs of contamination or damage, clean the balance pan, and externally calibrate using a 5g mass standard. If agreement is still not achieved, have the primary standards checked against an independent, certified weight of the same or greater confidence level of accuracy. If agreement is still not achieved, a technician should service the balance and the mass calibration should be repeated. For working mass standards, the assigned “true mass” equals the average mass of the six determinations. See the example of a calibration data worksheet below: 100 200 200 200 Weighing Starting Rep 16290 16289 100 100B T2 LE 200 200JE Tare Drift Direction Mass 1 100.001 199.999 99.967 199.961 199.992 200.016 0.001 → 16290 2 100.000 199.998 99.966 199.959 199.991 200.014 -0.001 → 16289 3 100.002 200.001 99.967 199.961 199.993 200.017 0.002 → 100B 4 100.000 199.999 99.968 199.959 199.991 200.015 0.002 → T2 5 100.001 199.999 99.967 199.960 199.992 200.016 0.001 → LE 6 100.000 199.999 99.967 199.959 199.993 200.014 0.000 → 200JE Average 100.0007 199.9992 99.9670 199.9598 199.9920 200.0153 0.0008 Std Dev 0.0008 0.0010 0.0006 0.0010 0.0009 0.0012 0.0012 Assigned 99.967 199.960 199.992 200.015 Cert. Mass 100.0012 200.0021 Uncertainty 0.0017 0.0015 Difference -0.0005 -0.0029 Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 23 of 25 Appendix B: Criteria Tables for PM2.5 FRM Sampling Critical Criteria must be met for result to be valid (unless there are compelling reasons and justification to not do so) Criteria Instrument EPA Range Internal EPA Current Documentation Checked Current Future Comment if results are qualified Flags Table (and frequency if not every sample) Class class By Tracking Tracking Filter Holding Times (see Operational table for pre-sampling holding time criteria) Sample recovery time from N/A critical <= 4 days A valid filter check-in log , FRM data AQM AQM, to LAB, to LIMS, AQM to LIMS to Sample recovered >96 hours sampler after sampling record, field sheets to report LASAR >4 days, <= 8 days B invalid > 8 days C invalid Filter holding times: N/A critical (<= 10 days and T <=25º C) or A valid Post-sampling holding time AQM and Time tracked by Time: LIMS to LASAR Post-sampling holding time or post-sampling (<= 30 days and T <=4º C) is documented in LIMS. Post- LAB database outside LIMS, temperature exceeded Additional guidance: For samples sampling temperature is to report. Temperature OR not weighed within 10 days, the documented on thermograph tracked by AQM, to Post-sampling holding time or temperature is maintained below charts and field sheets. LAB, to LIMS, to report temperature exceeded, but sample not 25C and the filter is weighed invalidated before a deadline (days) equal to: 34 minus ( estimated average temperature since removed from sampler). Not within above limits. B invalid Temperature: AQM to LIMS to LASAR Sampling period Sampling period duration P - sequential critical 1380 -1500 minutes A valid FRM data record, field sheet AQM Instrument, to AQM, to Instrument to LIMS to Sampling duration > 25 hours E - manual (Note: if sampling period is <1380 LAB, to report LASAR OR minutes and the concentration Sampling duration < 23 hours calculated based on 1440 minutes OR is a violation of the daily standard, Sampling duration < 23 hours but still then this sample is valid for the a NAAQS violation (required AIRS purpose of determining a violation flag) of the NAAQS) 1080 - 1379 minutes B invalid or 1501 - 1800 minutes sample period < 18 hours or > 30 C invalid hours Start Time no critical? Midnight ± 1 hour A valid Start time not at midnight ±1 hour Midnight ± 12 hour B invalid Sampling Instrument (see Operational table for additional non-critical sampler criteria) Average Flow Rate no critical avg within 5% of 16.67 lpm A valid FRM data record, field sheet AQM Instrument, to AQM, to Instrument to LIMS to Average flow not 16.67 lpm ± 5% (15.84 to 17.50 lpm) LAB, to report LASAR avg differs from 16.67 lpm by 5% B invalid to 20%. avg differs from 16.67 lpm by C invalid greater than 20% Flow Variability O - sequential critical CV <= 2% A valid FRM data record, field sheet AQM Instrument, to AQM, to Instrument to LIMS to Flow variability CV >2% C - manual LAB, to report LASAR 2% < CV <=4% B invalid note :instrument will CV >4% C invalid stop sampling if flow varies by > 10% from 16.67 for > 1 min, as indicated by flags: S - Seq and X - Man Filter Filter Defect or Damage N/A critical no defects A valid Post weighing lab book and AQM and AQM, to LAB, to LIMS, AQM or LAB to LIMS Filter damaged (visible any time after sampling) field sheet LAB to report to LASAR defect or damage judged to B invalid affect loading by <= 5%. defect or damage judged to C invalid affect loading by > 10%. Filter Conditioning N/A critical >=24 hrs A valid Weighing log books and LAB LAB, to LIMS, to report LIMS to LASAR Filter not conditioned properly (Pre and Post Sampling) control room log book <24 hours and > 2 hours B invalid < 2 hours C invalid Filter Conditioning: N/A critical 20º C <=(24 hr mean)<= 23º C A valid Weighing log books, control LAB LAB, to LIMS, to report LIMS to LASAR Filter not conditioned properly Temperature Range room log book, chart (Pre and Post Sampling) recorder output 24 hr mean >23º C B invalid and <=25º C, or < 20º C 24 hr mean >25º C C invalid (Post sampling only) Filter Conditioning: N/A critical SD is <= ± 2º C over 24 hr A valid Weighing log books, control LAB LAB, to LIMS, to report LIMS to LASAR Filter not conditioned properly Temperature Control room log book, chart (Pre and Post Sampling) recorder output SD is > ± 2º C and <= ± 4º C B invalid over 24 hr SD is > ± 4º C over 24 hr C invalid Filter Conditioning: N/A critical 24 hr mean prior to weighing is A valid Weighing log books, control LAB LAB, to LIMS, to report LIMS to report Filter not conditioned properly Humidity Range 30-40% room log book, chart (Pre and Post Sampling) Note: humidity can be between recorder output 20% and 30% if <= ± 5% of sampling RH. < 30 % or >40 % B invalid <1% or >80% C invalid Filter Conditioning: N/A critical SD over 24 hr is <= +/- 5% A valid Weighing log books, control LAB LAB, to LIMS, to report LIMS to LASAR Filter not conditioned properly Humidity Control room log book, chart (Pre and Post Sampling) recorder output SD over 24 hours is B invalid > 5% and <20% SD over 24 hours is C invalid >20% Filter Conditioning: N/A critical difference in 24 hr means is: A valid Weighing log books, control LAB LAB, to LIMS, to report LIMS to LASAR Filter not conditioned properly Humidity Control Comparison <= ± 5% room log book, chart of Pre and Post Sampling recorder output Conditions difference in 24 hr means is: B invalid > ± 5% and <= ± 20% difference in 24 hr means is: C invalid > ± 20% Balance location N/A critical in filter conditioning room A valid Balance maintenance LAB comment in LIMS same Balance not in conditioning room logbook not in filter conditioning room B invalid Calibration/Verification (see Operational table for additional calibration/verification criteria) Flow Rate Verification of NA operational <= ± 4% of audit standard A valid Monthly audit sheets AQM Internal review of audit same Flow rate verification failed Sampler 1/month sheets > 4% but <= 10% of audit standard B invalid >10% of audit standard C invalid Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 24 of 25 Operational criteria are used to maintain and evaluate the quality of the results. Operational criteria would only downgrade results if the criteria (or multiple criteria) indicates >10% (3 ug/M3 minimum) error for "B" class, or >20% (6ug/M3 minimum ) error for "C". Both "B" and "C" classed samples are invalid for EPA reporting purposes. Criteria Instrument EPA Range Currrent Documentation Checked Current Future Comment if data is qualified Flags Table (and frequency if not every sample) By Tracking Tracking Precision Precision: Collocated Samples NA operational CV <=10% for samples > 6 ug/m3 Duplicate site sampler AQM and Lab review during LASAR report? Primary versus duplicate results CV >10% checked at 25% of sites every 6 comparison report, LAB report validation for >6 ug/m3 samples: verified days generated monthly Accuracy Sampler Temperature Audit NA operational <= ±2º C QA section documentation QA QA to AQM LASAR report? NA (filter T and ambient T) checked each sampler 4 times per year Sampler Pressure Audit NA operational <= ±10 mm Hg QA section documentation QA QA to AQM LASAR report? NA checked each sampler 4 times per year Sampler Flow Rate Audit NA operational <= ± 4% of audit standard QA section documentation QA QA to AQM LASAR report? NA <= ± 5% of design flow rate 4/year Balance Audit NA operational manufacture's specifications Yearly balance Contracted Label on balance and same NA 1 time per year maintenance/service Maintenance notice from service Service company Calibration and Check Standards Audit Thermometer (QA and NA operational ± 0.1º C resolution, ± 0.5º C Manufacturer specs, AQM and QA To be developed To be developed NA AQM) accuracy, comparison to traceable check once per month (AQM) thermometer Audit Barometer (QA and NA operational ± 1 mm Hg resolution, Manufacturer specs, AQM and QA To be developed To be developed NA AQM) ± 5 mm Hg accuracy, comparison to traceable check once per month (AQM) barometer Audit Orifice (QA and AQM) systematic ± 0.08 Lpm resolution, Manufacturer specs, AQM and QA To be developed To be developed NA ± ?? Lpm accuracy, comparison to traceable flow calibrated to primary standard measurement device every 6 months (AQM) Working Mass standards - NA operational ± 0.025 mg from nominal value Weighing log book Lab Label on mass Label on mass NA Check checked 1/3 month standard containers standard containers Monitor Maintenance Sampler Impactor Maintenance NA operational cleaned/changed Field sheets AQM Check-in log book Same Sampler impactor was not maintained every 5 sampling events Sampler Inlet/downtube NA operational cleaned, monthly Monthly audit sheets AQM Internal review of audit same NA Cleaning sheets Sampler filter chamber NA operational cleaned, monthly Monthly audit sheets AQM Internal review of audit same NA Cleaning sheets Sampler Fan Filter Cleaning NA operational cleaned/changed, monthly Monthly audit sheets AQM Internal review of audit same NA sheets Sampler: Other Manufacturer NA operational Manufacturer's SOP Monthly audit sheets AQM Internal review of audit same NA Recommended Cleaning sheets Filter Checks Lot Filter Blank NA operational <= ±15 ug change between Weighing log book Lab Prior to use of any lot Results of LOT blank NA weighings at least 24 hours apart; in LIMS? 3 per lot Unexposed Filter Defects NA operational Pin holes, support ring separation, Log of filter examination Lab Do not use defective same NA unevenness, contaminant material; filters. Report to EPA if all filters examine prior to pre- number of defects sampling conditioning seem excessive. Filter Integrity or appearance NA operational Any unusual appearance of filter Field sheets and weighing AQM and Recorded in log book Recorded on paper Unusual filter loading appearance after exposure after sampling which do not affect log book LAB or field sheet, work, transferred to mass (see "critical" filter defect or transferred to LIMS, LIMS, easily include damage criteria above) comment used in report comment in report Filter Holding Times (see Critical table for additional filter holding times criteria) Pre-sampling holding times NA operational <30 days between pre-sample LIMS Lab LIMS and AQM to LIMS and AQM to Presampling filter holding time > 30 days weighing and use in sampling separate report to final LASAR report Lab QC Checks Lab Filter Blank NA operational <= ±15 ug change, Lab report Lab Quarterly report from LIMS report Weighing QC results not within control at least one per weighing session separate database limits Balance Check NA operational <= 3 ug; beginning, end, and every Weighing log book Lab Weighing not continued Weighing not Weighing QC results not within control 10th filter if unacceptable continued if not limits acceptable, notify by LIMS if attempt is made to continue weighing Duplicate Filter Weighing NA operational <= ±15ug per filter (or established Weighing log book Lab Quarterly report from LIMS report Weighing QC results not within control historical 2xSD, if better); separate database limits duplicate weighings performed on 10% of filters at both pre and post weighings sessions, reweighed same day Sampling Instrument (see Critical table for additional sampler excursion criteria) Sampling Flow Rate: F - seq. & man. operational No excursions > ± 5% for > 5 min FRM data record, field sheet AQM AQM to LAB to report LIMS to LASAR Sampling flow rate off set point by > ±5% 5 minute intervals for > 5 minutes--Required EPA flag Sampler Filter Temperature R - Sequential operational No excursions >5º C for >30 FRM data record AQM Instrument flag Download from Sampler filter temperature excursion >5º C Sensor T - Manual minutes investigated , results to instrument to LIMS, for >30 minutes--Required EPA flag Lab, to LIMS, to report investigate and confirm, modify LIMS Calibration/Verification (see Critical table for flow rate verification criteria) External Leak check NA operational <80 ml/min Field sheets, audit sheets, AQM Check-in log book Same Sampler failed leak test checked every 5 sampling events sampler log book Internal leak check NA operational <80 ml/min Field sheets, audit sheets, AQM Check-in log book Same Sampler failed leak test Only performed if fails external sampler log book leak check Temperature calibration of NA operational <= ± 2º C Calibration sheet AQM Sticker on instrument Same NA sampler on installation, then 1/yr and Maintenance schedule spreadsheet One point Temperature check NA operational <= ± 4º C Audit sheet, sampler log AQM Internal review of audit same Sampler failed temperature verification of sampler 1/4 weeks book sheets Pressure calibration of sampler NA operational <= ± 10 mm Hg Calibration sheet AQM Sticker on instrument Same NA on installation, then 1/yr and Maintenance schedule spreadsheet Pressure verification of NA operational <= ± 10 mm Hg Audit sheet, sampler log AQM Internal review of audit same Sampler failed pressure verification sampler 1/4 weeks book sheets Flow Rate calibration of NA operational <= ± 2% Calibration sheet AQM Sticker on instrument Same NA sampler on installation, then 1/yr and Maintenance schedule spreadsheet Clock/Timer Verification NA systematic 1 min/month, Audit sheets AQM To be developed same Sampler failed clock/timer verification checked once per 4 weeks Microbalance calibration NA operational per manufacture's specification Service records Lab Label on balance Same NA 1/yr Lab temperature verification NA operational <= ± 2º C Control room lab book Lab Label on room temp Same NA 1/6 month display Lab humidity verification NA operational <= ± 2% Control room lab book Lab Label on room temp Same NA 1/6 month display Department of Environmental Quality Gravimetric Analysis of Particulate Collected with R&P Partisol Samplers and MetOne SASS Samplers Date: June 27, 2003 Revision: 2.0 Page 25 of 25 Systematic Criteria may affect interpretation of the results but do not usually impact the validity of the results. Systematic criteria would only downgrade results if the criteria indicates >10% (3 ug/M3 minimum) error for "B" class, or >20% (6ug/M3 minimum ) error for "C" class. Both "B" and "C" samples are invalid for EPA reporting purposes Criteria Instrument EPA Range Documented Checked Current Future Comment if results are qualified Flags Table (and frequency if not every sample) By Tracking Tracking Data Reporting Criteria Data Completeness NA systematic >= 75% of quarterly data Reports, comparison to Lab/HQ HQ reports LIMS/LASAR reports NA from each site scheduled sampling Reporting Units NA systematic ug/m3 at ambient temp/pressure Reports Lab/HQ Lab review of Manual calculation of NA calculations, HQ review different (rotating of reported results monthly) sites results, at a frequency of 2 per site at 2 sites per month. Results Rounding - annual 3 yr NA systematic nearest 0.1 ug/m3 Reports submitted to EPA HQ HQ methods LIMS/LASAR should NA (>= 0.05 rounded up) generate similar reports Results Rounding - 24 hr, 3 yr NA systematic nearest 1 ug/m3 Reports submitted to EPA HQ HQ methods LIMS/LASAR should NA (>= 0.5 rounded up) generate similar reports Reporting Limits PM2.5 Detection Limit: Lower NA systematic <= 2 ug/M3 standard deviation of field Lab To be developed To be developed NA blanks <(24 x 2) ug, (I.e., <48ug per filter ? PM2.5 Detection Limit: Upper NA systematic >=200 ug/M3 Sampling downgraded due to AQM and To be developed To be developed NA effects of high loading LAB Primary Standards Recertifications Flow Rate Primary Standard NA systematic ± 2% of NIST-traceable standard, Certification documents AQM Documents posted with same NA recertified once every 2 years instrument Primary Reference NA systematic ± 0.1º C resolution, ± 0.5º C accuracy, Certification documents AQM Documentation on file same NA Thermometer ASTM certified Hg in glass, permament certification Primary Reference Barometer NA systematic ± 1 mm Hg resolution, Certification documents AQM To be developed same NA ± 5 mm Hg accuracy, ?frequency of certification? Primary Mass Stds NA systematic ± 0.025 mg from nominal value NVLAP certification Lab Label on mass Label on mass NA documents, lab book standard containers standard containers Microbalance Microbalance Readability NA systematic 1 ug, Manufacturer specs Lab LIMS records balance LIMS records balance NA checked at balance purchase used for weighing used for weighing Microbalance Repeatability NA systematic 1 ug, checked at annual maintenance Yearly balance check/service Lab Label placed on Label placed on NA balance balance Precision (determined by an independent organization? QA or EPA?) Single Analyzer Precision ? NA systematic CV <= 10% Report generated by EPA? EPA? EPA reports? EPA reports? NA 1/3 month Single Analyzer Precision ? NA systematic CV <= 10% Report generated by EPA? EPA? EPA reports? EPA reports? NA 1/year Reporting Organization NA systematic CV <= 10% Report generated by EPA? EPA? EPA reports? EPA reports? NA Precision ? 1/3 month Bias (determined by an independent organization? QA or EPA?) FRM Performance Evalution NA systematic ±10%, EPA report/QA section report EPA/QA EPA report QA section report NA checked at 25% of sites 4/year compared to LIMS report included in (AQM and Lab not directly involved) LIMS/LASAR
"STANDARD OPERATING PROCEDURE"