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Automated Karl Fischer water determinationwith the 774 Oven Sample Processor

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Automated Karl Fischer water determinationwith the 774 Oven Sample Processor Powered By Docstoc
					Application Bulletin 280/1 e

Automated Karl Fischer water determination
with the 774 Oven Sample Processor
Of interest to:
General analytical laboratories; Pharmaceutical industry; Petrochemistry; Plastics, photographic industry; Food analy-
sis
F 1, 4, 5, 6, 7



Summary                                                       Instruments and accessories
In principle the 774 Oven Sample Processor can be             774/Coulometer System
used with all samples that release their water when           2.774.0010 Oven Sample Processor
heat is applied. However, the KF oven method is es-
sential whenever direct volumetric or coulometric Karl        6.2419.000 Sample vessels for 774
Fischer titration is impossible because the sample            6.1448.050 Septum with sealing
contains interfering components or, due to its consis-        6.1808.040 Adapter for needle
tency, is difficult to place in the titration vessel.
                                                              6.1808.090 Adapter for needle
The combination of the 774 Oven Sample Processor
                                                              2.756.0110 KF Coulometer with diaphragm-less
with coulometric Karl Fischer titration (756 or 831 KF-
                                                                         generator cell or
Coulometer) is ideal for samples with a low water con-
tent. Foodstuff, pharmaceutical products, plastics or         2.831.0110 KF Coulometer with diaphragm-less
mineral oil products can be analyzed fully automaed                      generator cell
and extremely accurately. On the other hand, a volu-          2.728.0010 Magnetic Stirrer
metric Karl Fischer titration using a KF Titrino is to be     6.2125.110 Cable 774–PC
preferred for sample with a very high water content
(>50%).                                                       6.2134.040 Cable 756–PC
In accordance with the gas extraction principle the           6.2141.020 Remote cable 774–756
water is driven out of the heated sample by a stream of       6.6012.140 Metrodata TiNet 2.4
dry carrier gas and transferred to the titration vessel,      6.6008.200 Metrodata VESUV 3.0
where the water is determined by a KF titration.
                                                              6.5618.000 Test tool for oven temperature
For temperature-sensitive samples, e.g. foodstuff, the
                                                              2.767.0010 Calibrated Reference
water can be released gently at lower temperatures by
simultaneous extraction with methanol. In this way it is      774/Titrino System
possible to prevent any water released by decomposi-
tion.                                                         2.774.0010 Oven Sample Processor
This Application Bulletin uses examples from the food,        6.2419.000 Sample vessels for 774
pharmaceutical, plastics and petrochemical industries         6.1448.050 Septum with sealing
to describe automatic Karl Fischer water determination        6.1808.040 Adapter for needle
using the 774 Oven Sample Processor and a KF Cou-
                                                              6.1808.090 Adapter for needle
lometer. Information applying to the combination of the
Oven Sample Processor with a volumetric KF titrator is        2.758.0010 KFD Titrino or
given in brackets.                                            2.758.0020 KFD Titrino or
                                                              2.784.0010 KFP Titrino or
                                                              2.795.0010 KFT Titrino
                                                              2.728.0010 Magnetic Stirrer
                                                              6.3014.213 10 mL Exchange Unit
                                                              6.2125.110 Cable 774–PC
                                                              6.2134.040 Cable 758/784–PC
                                                              6.2141.020 Remote cable 774–758/784
                                                              6.6012.140 Metrodata TiNet 2.4
                                                              6.6008.200 Metrodata VESUV 3.0
                                                              6.5618.000 Test tool for oven temperature
                                                              2.767.0010 Calibrated Reference
Application Bulletin 280/1 e
Automatic KF water determination with the 774 Oven Sample Processor
Page 2/11


Reagents                                                  instruments themselves and, if necessary, modified to
                                                          suit the samples to be analyzed.
•   HYDRANAL Coulomat AG Oven, Riedel-de Haën
                                                          The flow rate of the carrier gas (air or N2) should lie
    no. 34739 (for coulometric KF titration)
                                                          between 40...60 mL/min. For solid samples 40 mL/min
•   HYDRANAL Methanol Dry, Riedel-de Haën no.             is normally used, for liquid samples 60 mL/min is set.
    34741 (as additional extraction agent or for volu-    The gas flow must be large enough to transfer the
    metric KF titration)                                  released moisture as quickly as possible to the titra-
•   HYDRANAL Composite 5, Riedel-de Haën no.              tion vessel, and small enough to guarantee the com-
    34805 (for volumetric KF titration)                   plete absorption of the water in the titration solution.
•   HYDRANAL Standard Sodium tartrate dihydrate,          The vessels for conditioning, system preparation,
    Riedel-de Haën no. 34803                              determination of the blank value (see under «Titration
                                                          sequence») and the sample vessels are placed on the
•   HYDRANAL Water Standard KF Oven (potassium
                                                          rack of the 774 Oven Sample Processor. For cou-
    citrate monohydrate), Riedel-de Haën no. 34748
                                                          lometric KF titration the titration vessel is filled with
    or                                                    150 mL HYDRANAL Coulomat AG Oven (for volumet-
•   Apura CombiCoulomat fritless, Merck no. 1.09257       ric KF titration with approx. 30 ... 40 mL HYDRANAL
    (for coulometric KF titration)                        Methanol Dry) and then conditioned.
•   Apura CombiTitrant 5, Merck no. 1.88005 (for vo-
    lumetric KF titration)                                Temperature ramps
•   Apura CombiSolvent, Merck no. 1.88008                 For samples whose temperature behavior is unknown
•   Apura Sodium tartrate dihydrate, Merck no.            a so-called temperature ramp is run (available tem-
    1.06664                                               perature range 50 ... 250 °C). The heating rate should
                                                          be selected so that it can be guaranteed that the
                                                          temperature can actually be achieved inside the sam-
•   Molecular sieve, pore size 0.3 nm, Metrohm no.
                                                          ple. Figure 1 shows a temperature ramp in which the
    6.2811.000
                                                          sample is heated from 50 °C to 250 °C in 100 min, i.e.
•   Carrier gas (air or N2)                               the heating rate is 2 °C/min.

Sample preparation
The sample is thoroughly mixed under conditions
which are as dry as possible. The sample weight de-
pends on the water content. Sample weights that are
too low have a negative effect on the measuring accu-
racy (weighing error); the maximum sample weight is
limited by the reagent capacity (1000 mg H2O per
100 mL reagent for HYDRANAL Coulomat AG Oven).
The absolute amount of water transferred to the titra-
tion vessel for analysis should be in the range 300 ...
1000 µg. We also recommend that the KF reagent is
changed once per week under «normal» operation,
more often if necessary.
The appropriate amount of sample are weighed into
the sample vessels, which should previously have
been conditioned for at least 24 h in the surrounding
                                                          Fig. 1:   Diagram showing a possible temperature ramp.
air. The vessels are then sealed with PTFE-coated
septa which have also been conditioned. When work-
ing gloves should be worn to avoid contamination of       While a temperature ramp is being recorded it is pos-
the samples and prevent contact with skin moisture.       sible to record both the amount of water released and
                                                          the drift as a function of time (see Fig. 5 and 6 in the
Table 2, page 6 makes the relationship between the        annex). By using the heating rate and the elapsed
amount of sample used in the analysis and its water       time it is possible to calculate the associated tempera-
content clear.                                            ture curve (see Fig. 2). This allows statements about
                                                          the kinetics of the water release as a function of the
Instrument preparation                                    temperature. In addition, with thermally unstable sam-
                                                          ples any decomposition reactions in which water is
On the 774 Oven Sample Processor the lift positions       released can be recognized.
for the conditioning vessel (rinsing position) and the
sample vessels (working position in the oven) as well
as the maximum lift path are configured. The previ-
ously programmed methods for the Oven Sample
Processor and the KF Coulometer (or the KF Titrino)
are called up by the TiNet software or directly on the
Application Bulletin 280/1 e
Automatic KF water determination with the 774 Oven Sample Processor
Page 3/11


                                                                                           tract all the water it contains. Any transfer of the water
                 20000                                             2500                    of decomposition formed in the titration vessel at
                                                                                           higher temperatures (from approx. 180 °C) must be
                                                                   2000                    avoided.
                 15000




                                                                          Drift [ug/min]
   Wasser [ug]




                                                                   1500
                 10000
                                                                   1000                    Analytical procedure
                 5000                                                                      Each analysis consists of the following steps:
                                                                   500
                                                                                           •   Conditioning the titration vessel
                    0                                             0
                                                                                           •   Extracting the water from the sample
                         50        100            150          200
                                                                                           •   Transporting the water to the titration vessel
                                         T [°C]                                            •   Karl Fischer titration
                                                                                           •   Calculation of the result
                              Wasser [ug]               Drift [ug/min]
                                                                                           Conditioning
Fig. 2:            Temperature curve of sodium tartrate dihydrate:                         Conditioning, i.e. titrating the titration vessel to dry-
                   amount of released water and the associated drift
                   as a function of the temperature.
                                                                                           ness is carried with the 774 Oven Sample Processor
                                                                                           in the so-called conditioning position. This condition-
                                                                                           ing step must be carried out before every determina-
In the temperature curve of the tartrate sample (see
                                                                                           tion. The oven is heated up to the selected analysis
Fig. 2) it can be seen that it releases its surface water
                                                                                           temperature. Then the needle moves to the sample
uniformly up to a temperature of approx. 110 °C. In                                        position. Only now is the water driven out of the sam-
parallel the drift sinks from approx. 500 µg/min to                                        ple by a combination of a dry stream of carrier gas
100 µg/min. Between 110 °C and 125 °C the water of                                         and the increased temperature of the oven and trans-
crystallization contained in the sodium tartrate di-                                       ferred to the KF titration vessel, where the determina-
hydrate is released; this can also be very clearly rec-                                    tion by a Karl Fischer titration takes place. This titra-
ognized by the occurrence of a «drift peak». When all                                      tion may be coulometric (with the 756 or 831 KF Cou-
the water has been driven out of the sample the drift                                      lometer) or – for samples with a high water content
sinks to its basic value of approx. 10 µg/min.                                             (>50%) – volumetric (with a Karl Fischer Titrino). The
The temperature curve is used to determine the opti-                                       latter method should be used if very small sample
mum oven temperature for driving out the water of the                                      weights and the associated large measuring inaccu-
sample. This temperature should be high enough for                                         racies are to be avoided.
the water to be extracted completely without any de-                                       The double hollow needle of the Oven Sample Proc-
composition of the sample occurring; the reaction time                                     essor can be lowered almost to the base of the sam-
should also be kept as short as possible. For sodium                                       ple vessel and in this way the carrier gas can be
tartrate dihydrate 160 °C are recommended as analy-                                        passed though the heated sample. With liquid sam-
sis temperature. The analytical procedure when re-                                         ples this achieves an additional extraction effect. For
cording a temperature ramp is the same as for a de-                                        the analysis of solid samples a shortened needle is
termination at a given, fixed temperature (see below).                                     normally used [this requires the use of special adapt-
Figure 3 shows the temperature curve of a sample of                                        ers (Ordering no. 6.1808.040 and 6.1808.090. In this
food which, after releasing all its water, starts to de-                                   way turbulent mixing of the sample and contamination
compose at approx. 180 °C.                                                                 of the following samples or the conditioning vessel by
                                                                                           substances adhering to the needle tip can be avoided.

                 10000                                              600                    Water extraction

                 8000                                               500                    Carrier gas dried by molecular sieve is passed
                                                                                           through or over the heated sample and drives out the
                                                                          Drift [ug/min]
   Wasser [ug]




                                                                    400
                 6000                                                                      water it contains (see Fig. 4). The temperature of the
                                                                    300                    oven can be varied according to the thermal stability
                 4000                                                                      of the sample.
                                                                    200
                 2000                                               100
                    0                                               0
                         50      100        150     200          250
                                         T [°C]

                              Wasser [ug]               Drift [ug/min]

Fig. 3:            Temperature curve of a food sample that starts to
                   decompose at 180 °C.
This temperature curve is used to select an analysis
temperature of 120 °C for the sample in order to ex-
Application Bulletin 280/1 e
Automatic KF water determination with the 774 Oven Sample Processor
Page 4/11


                         dry carrier gas                        In conditioning, during which the needle is located in
                                                                the conditioning vessel, any moisture contained in the
                                                                system is removed until a constant low drift in the
                                                                range 10 ... 20 µg/min is achieved. The conditioning
                                                                step must be carried out before each new analysis,
                                                                and also before system preparation and the determi-
                                    to the titration vessel     nation of the blank value. In combination with TiNet
                                                                the start of the sample series takes place via the
                                                                <COND> button; this starts conditioning both the
                                                                Oven Sample Processor and also the KF Coulometer
                                                                or KF Titrino. If the TiNet software is not used the
                                                                analysis is started with the <START> key of the 774
                                                                Oven Sample Processor. At this point the KF Cou-
                                                                lometer or the KF Titrino must be in the STOP mode.
                                  oven                          With automatic drift correction the drift value meas-
                                                                ured immediately before the determination will be
septum                                                          used for determining the water content of the sample
                         double hollow needle                   (subtracted).
                                                                System preparation means that the whole system will
                         sample                                 be adjusted to the selected conditions. An empty
                                                                sample vessel will be treated in exactly the same way
                                                                as the following samples, but the value obtained will
                                                                not be taken into account. We recommend that this
Fig. 4:   Sample vessel with double hollow needle.              step – which at the same time is used for checking
                                                                that the analysis system is working properly – is car-
                                                                ried out before each new sample series.
Thermosensitive samples can be gently analyzed at
lower temperatures by using HYDRANAL Methanol                   Apart from the water in the sample, the sample vessel
Dry as the extraction agent. This is placed in the sam-         also contains atmospheric humidity; this makes a
ple vessel together with the sample. Methanol supports          blank value determination necessary. If methanol is
the release of water, particularly during the boiling           used as an additional extraction agent then its water
process in the oven. It is transferred to the titration         content must also be determined, i.e. included in the
vessel together with the water but does not interfere           blank value. A three-fold determination of the blank
with the titration as the KF reagent also contains              value is normally sufficient. The mean value is stored
methanol.                                                       as a Common Variable and taken into account in the
                                                                calculation of the water content (subtracted).
It is generally advisable to set an extraction time. This
ensures that the driven off water is completely trans-          The system preparation and the blank value determi-
ferred to the titration vessel. We recommend a time of          nations must be carried out under exactly the same
180 seconds. If methanol is used as an additional               conditions as the analysis of the samples. In order to
extraction agent then it is important that a sufficiently       do this an empty system preparation vessel and three
long extraction time is selected in order to prevent a          empty (or filled with solvent) blank value vessels are
premature termination of the determination. In this             placed on the rack of the 774 Oven Sample Proces-
case we recommend at least 15 min.                              sors and processed before the samples.

Karl Fischer titration
For a coulometric Karl Fischer titration a modified KF
reagent is used which contains iodide. During the
determination the iodide is oxidized anodically (genera-
tor electrode) to iodine which then reacts with the wa-
ter. As this is an absolute method no titer adjustment is
necessary.
In volumetric Karl Fischer titration the titer of the titrant
must first be determined by using a certified water
standard. In combination with the 774 Oven Sample
Processor this is done by driving the water out of the
«KF Oven Standards» sodium tartrate dihydrate at
160 °C or potassium citrate monohydrate at 220 °C.

Titration sequence
The water content determined by the gas extraction
with subsequent KF titration is made up as follows:
Water contentabsolute
  = water contentsample + blank value + drift
Application Bulletin 280/1 e
Automatic KF water determination with the 774 Oven Sample Processor
Page 5/11


Instrument settings                                                   Validation of the analysis system
Tab. 1:     Control and titration parameters.                         GLP (Good Laboratory Practice) requires among
                                                                      other things, that the correctness and precision of
                         Parameter              Setting               analytical instruments are checked at regular intervals
Control parameters       EP at U                50 mV
                                                                      by using SOPs (Standard Operating Procedures). We
coulometry:                                                           recommend to validate the analytical system as a
                         dynamics               70 mV                 whole by carrying out a series of determinations with
                         max.rate               max. µg/min           certified standards (see Metrohm Application Bulletins
                                                                      No. 255, 273 and 281).
                         min.rate               15 µg/min
                                                                      The validation of the 774/Coulometer and 774/Karl
                         stop crit.             rel.drift             Fischer Titrino Systems is carried out by using sodium
                         rel.drift              10 µg/min             tartrate dihydrate or potassium citrate monohydrate
                                                                      (methods in Annex). These KF standards are supplied
Titration parameters     start drift            10 µg/min             with analysis certificates in which their exact water
coulometry:
                         I(pol)                 10 µA                 content is given. A 10-fold determination is carried out
                                                                      with different sample weights. The relative standard
Preselections            generator I            400 mA                deviation should be less than ≤2.0%.
coulometry:
                                                                      In addition to the start-up check routines of the in-
Control parameters       EP at U                250 mV                struments, the use of the built-in diagnosis programs
volumetry:
                         dynamics               100 mV                and regular service we also recommend to check the
                         max.rate               max. mL/min
                                                                      electronic components of the instruments (Coulometer
                                                                      or Karl Fischer titrino) by using the 767 Calibrated
                         min.volume incr.       min. µL               Reference.
                         stop crit.             drift                 A measuring insert for the heating block with a built-in
                         stop drift             20 µL/min             temperature sensor (6.5618.000) is used in combina-
                                                                      tion with a calibrated temperature measuring instru-
Titration parameters     titr.direction         –                     ment as an oven temperature test tool for the 774
volumetry:                                                            Oven Sample Processor. The measuring setup is
                         I(pol)                 50 µA
                                                                      inserted into the oven block in the same way as a
Oven settings:           initial temp.          depending on          sample vessel and fixed in position. When the set
                                                sample,               temperature has been reached the inner temperature
                                                normally 50 °C
                                                                      measured by the test tool is compared with the dis-
Gas flow:                flow rate              40...60 mL/min        play of the Oven Sample Processor. If the measured
                                                                      temperature varies greatly from the oven temperature
                         gas type               air or N2
                                                                      displayed (more than ±4 °C) please contact Metrohm
                         gas flow factor        1.0 (for air or N2)   Service.
                                                                      In order to check the gas flow of the Oven Sample
                                                                      Processor a calibrated flowmeter is included in the
Troubleshooting
                                                                      gas flow of the system and the flow rate measured by
Procedure in case of poor precision (reproducibility):                the test tool is compared with the set value. The per-
•   Optimize the titration and control parameters.                    missible tolerance of the flowmeter (with micro-bridge
                                                                      air flow sensor) built into the 774 Oven Sample Proc-
•   Check whether the sample vials are tightly sealed.                essor is ±20%. The external flowmeter cannot be
•   Drift too high: check titration cell, septum and/or               purchased from Metrohm AG.
    seals leaks, molecular sieve used up, poorly condi-
    tioned, ensure thorough mixing.
•   Clean electrodes: indicator electrode mechanically
    with moist polishing powder (aluminum oxide or
    toothpaste), rinse and dry; treat with conc. HNO3 or
    change the electrode; align Pt-pins parallel. Clean
    generator electrode with conc. HNO3.
•   KF reagent contaminated/used up: change the
    solution; use a different batch number if necessary.
•   Check electrical contacts.
•   Check oven temperature.
•   Balance: too inexact, drafts, temperature influ-
    ences, temperature equilibrium not reached, sam-
    ple weight not optimal/too low.
•   Possibly carry out a validation of the analysis sys-
    tem.
Application Bulletin 280/1 e
Automatic KF water determination with the 774 Oven Sample Processor
Page 6/11


Examples of applications                                        Sample                    T            Sample wt. Water content
                                                                                          [°C]         [g]        [ppm]
The following table provides an overview of samples
analyzed by the 774 Oven Sample Processor. In each              Pharmaceutical products:
case the Karl Fischer water determination was carried
                                                                Collagens                 160          0.07...0.4      106000...919000
out in combination with the 756 KF Coulometer using
N2 as the carrier gas (flow rate 40 mL/min). As well as         Denture cleaner,          70           0.2...1.5       38000
the determined water content the sample weights and             Effervescent ta-
                                                                       6
analysis temperatures are given.                                bletts
                                                                Drugs                     140          0.04            67000
Tab. 2:       Water content of samples from various branches    Lyophilizate              150          0.01            50000
              together with their analysis parameters.
                                                                Vitamin C                 80...90      0.1             30000
Sample                     T      Sample wt. Water content      Others:
                           [°C]   [g]        [ppm]
                                                                Sodium tartrate           160          0.02...0.08     155000
Foodstuff:                                                      dihydrate

Lyophilizate               120    0.06          14000           Potassium citrate         220          0.03            55500
                                                                monohydrate
          1
Aromas                     100    0.03...0.08   25000...54000
                                                                Methanol                  110          0.5             230
(Malto-)Dextrin            100    0.03...0.08   47000...88000
                                                                Polyammonium              220          0.03...0.3      10000...850000
Lactose monohy-            155    0.06          52000           compounds
drate
                                                                Emulsified fat com- 220                0.03...0.08     850000
Skimmed milk pow- 90              0.06          44000           pound
   2
der
                                                                Formamidosulfonic 220                  0.2...0.3       <10000
                       2
Whole milk powder 90              0.06          39000           acid
Sweet whey pow-            90     0.06          49000           Pigment                   100          0.03...0.3      79000
   2
der
                                                                Polyolether               150          0.6...1.3       1500
Glucose monohy-            90     0.06          89000
drate
      2                                                         Dibutene                  100...140 0.03               250

Maltose monohy-            120    0.06          59000           Inorganic salt            100          0.01...0.03     580
      3
drate                                                           Lithium cobaltite         100          0.45...1.0      64
Roast coffee,              145    0.06          48200           Building rubble
ground
                                                                Surface water             50...60      0.3             6000
Garlic powder              110    0.2           35000           Bound water               85...140     0.3             10000
Mineral mixtures           110    0.3           60000...70000
Plastics:                                                       1
                                                                    With the 774 Oven Sample Processor the dissolution of the sample
                                                                    in KF reagent, which is required in a direct Karl Fischer titration and
Polypropylene              170    3.0           380                 which frequently cannot be carried out completely, is no longer
                   4                                                necessary.
Polyethylene               115    3.0           40              2
                                                                    With the addition of 4 mL methanol as extraction reagent. Regular
Olefins                    180    3.0           100                 checks of the gas flow are necessary as there is a risk that the
                                                                    needle may be blocked.
Polyamide                  180    0.3           7800            3
                                                                    With the addition of 4 mL 1,5-pentandiol, extraction time 600 s.
Polyoxymethylene           170    0.3           1400            4
                                                                    20 ppm water could be determined as the detection limit.
(POM)                                                           5
                                                                    With self-expanding plastics only the surface water can be deter-
               5
Polystyrene                120    0.05...0.2    200...500           mined with the 774/756 System. The plastics also contain trapped
                                                                    water. This can only be calculated as the difference between the
Refinery products:                                                  total water and surface water; the total water is determined by
                                                                    completely dissolving the sample in p-xylene under heating and
Transformer oil            150    3.0           80                  subsequent volumetric Karl Fischer titration.
                                                                6
Mineral oil                120    1...3         10...100            Above 70 °C the contained carbonate decomposes.

Insulating oil             140    3             5
Crude oil                  140    2             500...1200
Additive                   120    0.01...0.03   44000
Antimony dialkyldi- 50...130      3.0           700
thiocarbamate in
crude oil
Application Bulletin 280/1 e
Automatic KF water determination with the 774 Oven Sample Processor
Page 7/11


Literature                                                   •    Instructions for use of 758 KFD Titrino.
•   Metrohm Application Bulletin No. 137                     •    Instructions for use of 795 KFP Titrino.
    Karl Fischer water determination with the KF cou-        •    Instructions for use of 767 Calibrated Reference.
    lometer.                                                 •    Metrohm leaflet 8.110.1663
•   Metrohm Application Bulletin No. 255                          6.5618.000 measuring set for checking the tem-
    Validation of Metrohm KF titrators and KF ovens               perature of the 774 Oven Sample Processor.
    according to GLP/ISO 9001.                               •    Metrohm leaflet 8.110.1643
•   Metrohm Application Bulletin No. 273                          Checking the gas flow of the 774 Oven Sample
    Validation of Metrohm KF Coulometers using Stan-              Processor.
    dard Operating Procedures.                               •    HYDRANAL Manual
•   Instructions for use of 774 Oven Sample Proces-               Eugen Scholz reagents for Karl Fischer Titrations,
    sor.                                                          2006.
•   Instructions for use of 756/ 831 KF Coulometer.



Schematic diagram of the 774 Oven Sample Processor and 756 KF Coulometer analysis system




                             Water


                                                                                               TiNet
                                                                                                2.4

                                                         756 KF
                                                                                                             LPT 1
                                   stirrer 728
                                                                                                             COM 1
        Oven Sample
                                                                                                             COM 2
        Processor 774

                                                                              6.2134.040

                                                        6.2125.060
Application Bulletin 280/1 e
Automatic KF water determination with the 774 Oven Sample Processor
Page 8/11


Appendix
Parameter report for a temperature ramp (created with Metrodata TiNet 2.4)
'pf                                                      Max. titr. time OFF s
Date 01.03.2001 Time 15:10:11                            Drift correction
Method: temperature gradient                             Auto drift correction
Stored 01.03.01                                          Save data
>Start                                                   Curve ON
Common variables                                         Interval for meas. 5 s
Name Blankvalue                                          Save changes only OFF
Value 89.4                                               EP ON
Comment                                                  C4# from Coulometer OFF
Method variables                                         >Calculations, Berechnungen
Name SmplSize                                            Formulas
Assign &SmplSize                                         RS
Comment SmplSize                                         Content
>Start sequence, Startsequenz                            ('KFC.EP1'-'Blankvalue')/'SmplSize';ppm;1;0;
Instrument 774_1                                         Content%
Sample variable reset                                    ('KFC.EP1'-
>Calculations, Shiftrate                                 'Blankvalue')/10000/'SmplSize';%;4;0;
Formulas                                                 >Report, Report
Transfer                                                 Database
From TiNet to devices                                    Select data
To device 774_1                                          Curve ON
To path &m.ch.sh"15"                                     Result report ON
Comment                                                  Parameter report ON
>Sequence, Sequence                                      Save in water
Instrument 774_1                                         Print layout
Sequence used as ... RMove                               Print options
>Oven settings, OvenSetting                              Font width 12
Sample temp. 50 °C                                       Report per determination
Oven heat.time OFF min                                   Print immediately OFF
Conditioning ON                                          Multipage printout
>Wait Oven temp., WaitOvenTemp                           page numbers OFF
Timeout 0 min                                            Header on each page OFF
Error message OFF                                        Footer on each page OFF
>Feed sample, Probe zuführen                             Print in reverse order OFF
Instrument 774_1                                         Layout
Next sample                                              Text
Feed sample to...                                        Print result report line(s)...
Station 1                                                Report ident. ON
Sample heating                                           Date ON
Sample temp. 50                                          Method ON
Conditioning ON                                          EP variables ON
>Sequence, Sequenz                                       C4X variables OFF
Instrument 774_1                                         Other variables OFF
Sequence used as ... RMove                               Common variables ON
>Oven settings, Ofen Einstellung                         Results ON
Sample temp. 140 °C                                      Satistics OFF
Oven heat.time 45 min                                    Report blocks
Conditioning OFF                                         Results
>KFC, KFC                                                >Remove sample, Probe wegfahren
Instrument 756_1                                         Instrument 774_1
Parameters                                               Remove sample from ...
Control parameters                                       Station 1
EP U 50 mV                                               >End sequence, Endsequenz
Dynamics 70 mV                                           Instrument 774_1
Max.rate max. ug/min
Min.rate 15 ug/min
Titration parameters
Extr. time 2700 s
I(pol) 10 uA
Electrode test ON
Temperature 25.0 °C
Cell type no diaph.
I generator 400 mA
Start conditions
Pause 0 s
Start drift 10 ug/min
Time cond.ok 60 s
Activate pulse OFF
Stop parameters
Rel. drift 5 ug/min
Application Bulletin 280/1 e
Automatic KF water determination with the 774 Oven Sample Processor
Page 9/11


Parameter report for a KF water determination with selectable analysis temperature T = ‘ID1’
(created with Metrodata TiNet 2.4)
'pf                                                      Interval for meas. 20 s
Date 16.08.2001 Time 17:14:51                            Save changes only ON
Method: samplevartemp                                    EP ON
Stored 14.03.01                                          C4# from Coulometer ON
>Start                                                   >Calculations, Calculations
Common variables                                         Formulas
Name Blankvalue                                          RS
Value 112.9                                              Content
Comment                                                  ('KFC.EP1'-'Blankvalue')/'SmplSize';ppm;1;0;
Method variables                                         %Content
Name SmplSize                                            ('KFC.EP1'-
Assign &SmplSize                                         'Blankvalue')/10000/'SmplSize';%;4;0;
Comment SmplSize                                         >Report, Report
Name Id1                                                 Database
Assign &Id1                                              Select data
Comment Identifikation                                   Curve ON
>Start sequence, Start sequence                          Result report ON
Instrument 774_1                                         Parameter report ON
Sample variable reset                                    Save in water
>Calculations, Shiftrate                                 Print layout
Formulas                                                 Print options
Transfer                                                 Font width 12
From TiNet to devices                                    Report per determination
To device 774_1                                          Print immediately OFF
To path &m.ch.sh"15"                                     Multipage printout
Comment                                                  page numbers OFF
>Sequence, Sequence                                      Header on each page OFF
Instrument 774_1                                         Footer on each page OFF
Sequence used as ... RMove                               Print in reverse order OFF
>Oven settings, OvenSetting                              Layout
Sample temp. ='Id1' °C                                   Text
Oven heat.time OFF min                                   Print result report line(s)...
Conditioning ON                                          Report ident. ON
>Wait Oven temp., WaitOvenTemp                           Date ON
Timeout 0 min                                            Method ON
Error message OFF                                        EP variables ON
>Feed sample, Feed smpl                                  C4X variables OFF
Instrument 774_1                                         Other variables OFF
Next sample                                              Common variables ON
Feed sample to...                                        Results ON
Station 1                                                Satistics OFF
Sample heating                                           Report blocks
Sample temp. ='Id1'                                      Results
Conditioning ON                                          Curve
>KFC, KFC                                                From proc. KFC
Instrument 756_1                                         x axis
Parameters                                               Quantity t/s
Control parameters                                       Scaling Auto
EP U 50 mV                                               y axis
Dynamics 70 mV                                           Quantity ug H2O
Max.rate max. ug/min                                     Scaling Auto
Min.rate 15 ug/min                                       Color
Titration parameters                                     Curve 1 Auto
Extr. time 1000 s                                        Curve 2 Auto
I(pol) 10 uA                                             Layout
Electrode test ON                                        Grid ON
Temperature 25.0 °C                                      Curve
Cell type no diaph.                                      From proc. KFC
I generator 400 mA                                       x axis
Start conditions                                         Quantity t/s
Pause 0 s                                                Scaling Auto
Start drift 10 ug/min                                    y axis
Time cond.ok 60 s                                        Quantity Meas
Activate pulse OFF                                       Scaling Auto
Stop parameters                                          Color
Rel. drift 10 ug/min                                     Curve 1 Auto
Max. titr. time OFF s                                    Curve 2 Auto
Drift correction                                         Layout
Auto drift correction                                    Grid ON
Save data                                                >Remove sample, Remove smpl
Curve ON                                                 Instrument 774_1
Application Bulletin 280/1 e
Automatic KF water determination with the 774 Oven Sample Processor
Page 10/11


Remove sample from ...
Station 1
>Sequence, Endsequence
Instrument 774_1
Sequence used as ... CMove
>Shift, Shift
Next sample
Beaker shift to...
Station 1
>RinsePosition, RinsePosition
Station 1
Application Bulletin 280/1 e
Automatic KF water determination with the 774 Oven Sample Processor
Page 11/11


Method for validating the 774/756 system using sodium tartrate dihydrate
(created with 756 KF Coulometer)
 'pa
756 KF Coulometer              5.756.0010                              2500
                                                                                                                                              1500
date 1999-12-14      time 16:27         6                                                                          Wasser
KFC-B            774-D j3                                                                                          [µg]
                                                                       2000
parameters                                                                                                                                    1250

>control parameters
  EP at U                 ..50 mV




                                                                                                                                                     Drift [µg/min]
                                                                                                                                              1000
                                                                       1500
  dynamics                  70 mV




                                                         Wasser [µg]
  max.rate                max. µg/min                                                                                                         750
  min.rate                  15 µg/min                                  1000
  stop crit:         rel.drift                                                                                                                500
  rel.drift                  5 µg/min                                                     Drift
>titration parameters                                                  500                [µg/min]
                                                                                                                                              250
  pause                      0 s
  extr.time                180 s
  start drift                10 µg/min                                   0                                                                    0
                                                                              0     100    200       300     400     500    600   700   800
  temperature             25.0 °C                                                                          t [s]
  time interval              2 s
  max.titr.time            OFF s                          Fig. 5:                 Titration curves for the determination of the water
>statistics                                                                       content of sodium tartrate dihydrate: released
  status:                  OFF                                                    amount of water and drift as a function of time
>preselections                                                                    (conditions: T = 160 °C, 40 mL/min N2, headspace
  drift corr:             auto                                                    technique).
  req.ident:               OFF
  req.smpl size:           OFF
  smpl unit:                 g
  limit smpl size:         OFF                            The determinations were carried out in 150 mL HY-
  text id1          id1 or C21                            DRANAL Coulomat AG Oven. The theoretical water
  text id2          id2 or C22
  text id3          id3 or C23
                                                          content of the standard substance (Apura sodium
  oven:                   COM1                            tartrate dihydrate from Merck) was 15.65% according
  activate pulse:          OFF                            to the analysis certificate. Within this validation context
           ============                                   the content was determined as being 15.680 ±
                                                          0.032 % water (srel = 0.21%); this corresponds to a
                                                          recovery rate of 100.2%.
 'fm
756 KF Coulometer             5.756.0010
date 1999-12-14      time 16:27        6
KFC-B           774-D j3
>calculations
blank=C39;1;µg
content=(H2O-C39)*C01/C00/C02;1;ppm
Water=(H2O-C39)*C03/C00/C04/C05;3;%
C00=              0.01466
C01=                  1.0
C02=                  1.0
C03=                  100
C04=                 1000
C05=                 1000
C39=                 51.5
          ============


 'fr
756 KF Coulometer                5.756.0010
date 1999-12-14      time    16:26        6
KFC-B            774-D j3
smpl size         0.01466   g
smpl heat.time        756   s
sample temp.        160.0   °C
lowest temp.        158.7   °C
highest temp.       160.6   °C
gas flow             38.5   mL/min
drift auto            3.5   µg/min
titr.time             775   s
H2O                2346.9   µg
blank                51.5   µg
content          156575.7   ppm
Water              15.658   %
           ============
Application Bulletin 280/1 e
Automatic KF water determination with the 774 Oven Sample Processor
Page 12/11


Method for validating the 774/756 system using potassium citrate monohydrate
(created with 756 KF Coulometer)
 'pa
756 KF Coulometer              5.756.0010                                                                                               1100
date 1999-10-28      time 16:31        11                          1500
                                                                                                                                        1000
                                                                                                             Wasser
KFC-B            774-D j2                                                                                    [µg]                       900
parameters                                                         1250
>control parameters                                                                                                                     800

  EP at U………………………………………..50 mV                                    1000                                                                 700




                                                                                                                                              Drift [µg/min]
                                                         Wasser [µg]
  dynamics                  70 mV                                                                                                       600
  max.rate                max. µg/min                                  750                                                              500
  min.rate                  15 µg/min
  stop crit:         rel.drift                                                                                                          400
                                                                       500
  rel.drift                  5 µg/min                                                                                                   300
>titration parameters                                                                             Drift
                                                                                                                                        200
                                                                       250                        [µg/min]
  pause                      0 s
                                                                                                                                        100
  extr.time                180 s
                                                                        0                                                               0
  start drift                10 µg/min
                                                                             0       100    200         300           400   500   600
  temperature             25.0 °C                                                                       t [s]
  time interval              2 s
  max.titr.time            OFF s                         Fig. 6:                 Titration curves for the determination of the water
>statistics                                                                      content of potassium citrate monohydrate: released
  status:                  OFF                                                   amount of water and drift as a function of time
>preselections
                                                                                 (conditions: T = 220 °C, 40 mL/min N2, headspace
  drift corr:             auto
                                                                                 technique).
  req.ident:               OFF
  req.smpl size:           OFF
  smpl unit:                 g
  limit smpl size:         OFF                           The determinations were carried out in 100 mL HY-
  text id1          id1 or C21
  text id2          id2 or C22
                                                         DRANAL Coulomat AG Oven plus 50 mL methanol.
  text id3          id3 or C23                           The theoretical water content of the standard sub-
  oven:                   COM1                           stance (HYDRANAL Water Standard KF Oven from
  activate pulse:          OFF                           Riedel-de Haën) was 5.59% according to the analysis
           ============                                  certificate. Within this validation context the content
                                                         was determined as being 5.589 ± 0.049 % water (srel =
                                                         0.88%); this corresponds to a recovery rate of 100.0%.
 'fm
756 KF Coulometer             5.756.0010
date 1999-10-28      time 16:31       11
KFC-B           774-D j2
>calculations
blank=C39;1;µg
content=(H2O-C39)*C01/C00/C02;1;ppm
Water=(H2O-C39)*C03/C00/C04/C05;3;%
C00=              0.02588
C01=                  1.0
C02=                  1.0
C03=                  100
C04=                 1000
C05=                 1000
C39=                 74.4
          ============


 'fr
756 KF Coulometer                5.756.0010
date 1999-10-28      time    16:30       11
KFC-B            774-D j2
smpl size         0.02588   g
smpl heat.time        592   s
sample temp.        220.0   °C
lowest temp.        218.1   °C
highest temp.       220.3   °C
gas flow             39.2   mL/min
drift auto            4.6   µg/min
titr.time             613   s
H2O                1520.9   µg
blank                74.4   µg
content           55892.6   ppm
Water               5.589   %
           ============

				
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Description: Application Bulletin 280/1 e