Docstoc
EXCLUSIVE OFFER FOR DOCSTOC USERS
Try the all-new QuickBooks Online for FREE.  No credit card required.

Recent Analytical Challenges Proportionality Studies

Document Sample
Recent Analytical Challenges Proportionality  Studies Powered By Docstoc
					Recent Analytical Challenges:
   Proportionality Studies

    Environmental Protection Agency
       Office of Pesticide Programs
Biological and Economic Analysis Division

      Analytical Chemistry Branch
           Fort Meade, MD

          Lynda Podhorniak
Residue levels found on crops acquired during Crop Field Trials factor into
                               tolerances.
            General OPP Policy


Currently, not all residue data acquired from
 crop field trials can be used for projecting
                   tolerances.

Only residue data acquired from studies
   conducted within + 25% of a label
   application rate are used without
              adjustment.
              Hypothetical Example:
                  Crop Field Trial for pesticide XYZ on crop ABC :

                  Tolerance        Residues Found       Application rate



REQUESTED:
                   1 ppm                0.9 ppm             1 lb/acre

                                       assumed              assumed
PROJECTED:        0.5 ppm              0.45 ppm            0.5 lb/acre


  This data would not be used and another crop field trial would be requested.
      Application Rates & Residue Levels



No previous rigorous studies or empirical
        data exist to demonstrate a
 linear/proportional relationship between
application rates and residue levels found.


 The EPA OPP Heath Effects
 Division (HED) would like to
build a case for proportionality.
                                         (IR-4)
           USDA Interregional Research Project Number 4
        Expanded Their Existing 1X Crop Field Trials




•   Acequinocyl – cherries
•   Cyazofamid – cabbage
•   Etoxazole – mint foliage
•   Novaluron – peppers, snap beans & foliage
•   Spirodiclofen – blueberries
•   Triflumazole – cabbage
          Study Designed by HED
4 Samples from each field x 4 fields + 2 control=18 samples

• Acequinocyl – cherries             1X, 2X, 4X + untreated
  Cyazofamid – cabbage          ½X, 1X, 2X, 4X + untreated
• Etoxazole – mint foliage      ½X, 1X, 2X, 4X + untreated
  Novaluron – peppers           ½X, 1X, 2X, 4X + untreated
               snap beans       ½X, 1X, 2X, 4X + untreated
               bean foliage     ½X, 1X, 2X, 4X + untreated
  Spirodiclofen – blueberries   ½X, 1X, 2X, 4X + untreated
  Triflumazole – cabbage        ½X, 1X, 2X, 4X + untreated
      Insecticides
      Insecticides
    • Miticides
    • Miticides
      Fungicides
      Fungicides
IR-4 Crop Field Trial of Snap Beans
IR-4 Crop Field Trial of Cherries
    (IR-4) Support of This Study
• IR-4 growers located in:
-   Salisbury, MD
-   Las Cruces, NM
-   Paterson, Prosser, WA
-   Brighton, CO


• IR-4 LABS analyzed 1X samples:
    – U.C. DAVIS   (Western Regional Lab)

    – Cornell University   (New York)

    – Michigan State University         (North Central Research Center)

    – Morse Labs (Sacramento, CA)
IR-4 stored the crops and shipped the crops to ACB.
Chuck Stafford tackles the tough mint samples.
          MINT FOLIAGE




Whole mint plants are now more manageable.
         AFTER USING LBS OF DRY ICE



ROBOT COUPE
FINISHED MINT COMPOSITE
            ETOXAZOLE METHOD: developed for cottonseed
                                            cotton

              10.0 g sample, 150 mL acetone, blend 10 min


                            filter, evaporate

          40 mL, 40 mL, 50 mL CH2Cl2 partition, sep funnel 1

                            filter, evaporate


     75 mL hexane/ACN; 50 mL ACN/ hexane (2x) partition, sep funnel 2

                            evaporate to dry

                            I                   II
                                                               5 mL (3X) 5% ethyl acetate:hexane
5 mL (2x) hexane

                           Silica Gel cleanup




                   hexane, discard     evaporate to dry



                                        1.0 mL acetone


                                          GC/NPD
       ETOXAZOLE IR-4 Western Region Lab Method Modifications for Mint:

                      10.0 g mint, 150 mL acetone, blend 10 min

                                    filter, evaporate

                  40 mL, 40 mL, 50 mL CH2Cl2 partition, sep funnel 1


                                    filter, evaporate

             75 mL hexane/ACN; 50 mL ACN/ hexane (2x) partition, sep funnel 2


                                    evaporate to dry

                                I                        II                  5 mL (3X) 5% ethyl acetate:hexane

 25 mL (2x) hexane                                                            25 mL 5% IPA/hexane
30 mL 2% IPA/hexane
15 mL 5% IPA/hexane
                                Silica Gel cleanup


                                                        Carbon SPE
                        hexane, discard
                                                          evaporate to dry


                                                   0.1% corn oil /acetone

                                                              GC/MSD
                       Tandem Si and Carbon SPE
 ETOXAZOLE -
 mint sample cleanup



25 mL 5% IPA/hexane
ETOXAZOLE
   Etoxazole – RTX-5 column – GC/MSD
Abundance


                                                 TIC: 0701_29_63.D
      9500                                   15.08
      9000

      8500

      8000

      7500
                                           ETOXAZOLE 0.1 ug/mL
      7000

      6500

      6000

      5500

      5000

      4500

      4000

      3500

      3000

      2500

      2000

      1500

      1000

          500

            0
                 5.00        10.00          15.00            20.00        25.00          30.00   35.00
Time-->




  Abundance


                                          TIC: 0701_29_66.D

      42000

      40000

      38000

      36000
                          MINT CONTROL 1:10 dilution
                                                                  MINT CONTROL
      34000

      32000

      30000

      28000

      26000

      24000

      22000

      20000

      18000

      16000

      14000

      12000

      10000

          8000

          6000
                                                     15.12
          4000

          2000


                 14.20   14.40   14.60   14.80   15.00   15.20   15.40   15.60   15.80
      Etoxazole in mint Spike 0.1 ppm
Abundance


                                                           TIC: 0701_29_50.D

     44000

     42000

     40000
                                                           MINT SPIKE 0.1 ppm
     38000

     36000

     34000

     32000

     30000
                                                                                                   TIC
     28000

     26000

     24000

     22000                                 15.10

     20000

     18000

     16000

     14000

     12000

     10000

      8000                                15.05
      6000

      4000

      2000

                 14.60 14.80 15.00 15.20 15.40 15.60 15.80 16.00 16.20 16.40 16.60 16.80
Time-->

          Abundance


                                    Ion 300.00 (299.70 to 300.70): 0701_29_52.D
               11500

               11000

               10500

               10000          ETOXAZOLE SPIKE @ 0.1 ppm

                9500

                9000
                                                                                                  Ion 300
                8500

                8000

                7500

                7000

                6500

                6000
                                                             15.10
                5500

                5000

                4500

                4000

                3500

                3000

                2500

                2000

                1500

                1000

                 500

                      0
                          14.20   14.40   14.60   14.80   15.00   15.20   15.40   15.60   15.80
Pat is ready to move on to NOVALURON
                                     NOVALURON METHOD
                                    (cabbage, potatoes and apples)

                        10.0 g (sample), 100 mL Methanol:H2O (70:30), homogenize (2x)


                                               filter thru celite              final vol adjusted to 250 mL
                                    25 mL aliquot, evaporate to aqueous

                                          transfer with 10 mL 5% NaCl

                                       hexane (2x) partition, glass tube


                                                    evaporate
                                                I                   II
                                                                                 3 mL diethyl ether:ethyl acetate (50:50)
 hexane
3 mL diethyl ether:hexane (20:80)                                                5 mL acetone:hexane (50:50)
3 mL diethyl ether:hexane (50:50)                   NH2 SPE




                                     hexane, discard        evaporate to dry



                                                            Ethyl acetate


                                                                GC/ECD
                         Cornell Modified NOVALURON Method
                                         (snap beans & foliage)
                        10.0 g (sample), 100 200 mL Methanol:H2O (70:30), homogenize
                                                 175 mL Methanol ,homogenize

                                      filter thru celite GF/A filter paper      final vol adjusted to 400 mL
                                    25 mL 80 mL aliquot, evaporate to aqueous

                                         transfer with 10 mL 5% NaCl

                                      hexane (2x) (3x) partition, glass tube


                                                     evaporate
                                                 I                II
                                                                                   3 mL diethyl ether:ethyl acetate (50:50)
 hexane
3 mL diethyl ether:hexane (20:80)                                                  5 mL acetone:hexane (50:50)
3 mL diethyl ether:hexane (50:50)                    NH2 SPE




                                     hexane, discard        evaporate to dry low level



                                                            Ethyl acetate hexane


                                                                 GC/ECD
    Novaluron in cabbage using ECD




Chromatography from a Single Residue Method
           submitted to the EPA.
NOVALURON – SNAP BEANS using µECD

                                    0.01 ug/mL




    NO SPE                     Control




    NO SPE
               Novaluron
                             Spike 0.05 ppm
Change in temperature program – still seeing interferences




                  NO SPE
                                               Control




                   NO SPE
                                     Spike 0.05 ppm
   NH2 Cleanup Added back to method:

                                  Control




Spike recoveries are still 140%




                 Spike 0.05 ppm
       Novaluron 0.01 ug/mL MATRIX STANDARD




Spike recoveries are now 112%



       Spike 0.05 ppm SNAP BEANS
                             Novaluron - Foliage

                                                   Control




Spike recoveries in hexane: 140%
Spike recoveries in matrix standards: 108%


                                                   0.01 ug/mL matrix standard




                                             Spike 1 ppm
          Michigan State University MINATURIZED NOVALURON METHOD
                                                 (Peppers)

                        10.0 5.0 g (sample), 100 50 mL Methanol:H2O (70:30), homogenize (2x)


                                               filter thru celite        final vol adjusted to 125 mL
                                    25 mL aliquot, evaporate to aqueous

                                          transfer with 10 mL 5% NaCl

                                       hexane (3x) partition, glass tube


                                                    evaporate
                                                I                   II
                                                                               3 mL diethyl ether:ethyl acetate (50:50)
 hexane
3 mL diethyl ether:hexane (20:80)                                              5 mL acetone:hexane (50:50)
3 mL diethyl ether:hexane (50:50)                   NH2 SPE




                                     hexane, discard        evaporate to dry



                                                            Ethyl acetate


                                                                GC/ECD
      Novaluron – peppers - final solvent ethyl acetate




Spike recoveries are 68-70% using ethyl acetate.
                                                    Peppers
                                                   Spike 0.05 ppm
                   Peppers - Novaluron - µECD


                                                   Control




Spike recoveries are now 85% using matrix standards.


                                        0.05 ug/mL
                                        Matrix std

                                        1:8 dilution




                                                   ½X
       Changes to 5 of 6 methods:
• Instrumental:     column
                    temperature program
                    inlet – splitless to split
                    mobile phase
                    ion selection

• Cleanup:    SPE added or SPE removed

• Extraction: solvent changes

• Standards: in matrix
2 important messages…
                   RAM INDEX
http://www.epa.gov/oppbead1/methods/ram12b.htm
 Specialized glassware $10,000




Single residue methods are IMPRACTICAL:
and the answer is…
    Etoxazole Results – Mint foliage




Application rate       Levels found   (%CV)

½ x = 0.1 lb ai/acre    2.8 ppm (14.6)
1x = 0.2 lb ai/acre     11 ppm (23.7)
2x = 0.4 lb ai/acre     18 ppm (12.4)
4x = 0.8 lb ai/acre     52 ppm (16.5)
              Novaluron Results




                  Foliage             Snap beans
Application rate Levels found (%CV)   Levels found
½ x = 0.04 lb ai/acre 6.6 ppm (11)     0.09 ppm
1x = 0.08 lb ai/acre  8.9 ppm (12)     0.15 ppm
2x = 0.16 lb ai/acre  27 ppm (14)      0.42 ppm
4x = 0.32 lb ai/acre  53 ppm (5)       0.58 ppm
                                                                     ETOXAZOLE in mint


                                                  60
                                                  50




                                      PPM FOUND
                                                  40
                                                  30
                                                  20
                                                  10
                                                  0
                                                           0.5            1                                 2               4
                                                                         APPLICATION RATE




                        NOVALURON in snap beans                                                                        NOVALURON in bean foliage

                                                                                                   60
                                                                                                   50


                                                                                  Avg. ppm found
            0.800                                                                                  40
ppm found




            0.600                                                                                  30
            0.400                                                                                  20
            0.200                                                                                  10
            0.000                                                                                  0
                    0    1        2                    3         4            5                         0       0.05      0.1     0.15      0.2     0.25      0.3   0.35
                                Application Rates                                                                      Application Rates (pounds a.i./acre)
             Conclusions



The final decisions will be made by the
 risk mangers and the policy makers.
  Other ACB Proportionality project chemists:
      Triflumazole      Cyazofamid &Spirodiclofen     Spirodiclofen & Cyazofamid




       Alaa Kamel
                                                               Yaorong Qian
                           Elizabeth Kolbe

Novaluron & Etoxazole
                         Acequinocyl
                                                    Triflumazole, Cyazofamid & Acequinocyl




Pat Schermerhorn        Paul Golden                           Greg Verdin
                        Acknowledgements

                             EPA/OPP CHEMISTS:
David Miller, Chief, Chemistry & Exposure Branch, Heath Effects Division
David Hrdy, Senior Scientist, Chemistry & Exposure Branch, Heath Effects Division
Philip Villanueva, Mathematical Statistician, Health Effects Division

                             IR-4:
  •   Dan Kunkel & Johannes Corley, IR-4 HQ at Rutgers coordinated the
      project with HED & ACB and provided IR-4 Crop Field Trial photos.
  •   Emy Pfeil, IR-4 Beltsville BARC lab, stored samples in IR-4 freezer &
      offered us her equipment to homogenize some of the samples.

  Method discussions with the IR-4 Regional Labs:
  • Matt Hengel, UC-Davis lab (etoxazole, cyazofamid, acequinocyl)
  • Inga-Mai Larsson-Kovack, IR-4 Cornell Analytical Lab, Cornell University
    Geneva, NY (novaluron/green beans)
  • Wayne Jiang, IR-4 North Central Research Center Michigan State
    University lab – (novaluron/peppers)
  • Todd Wilcox- IR-4 lab in WA (spirodiclofen)
See you next year!

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:4
posted:9/16/2011
language:English
pages:45