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									Arkansas Department of Health
   Division of Public Health
         Laboratories
     Joe Mobley, Paula Barnes, Joseph Dussex
Arkansas Department of Health, Organic Water Laboratory,
      4815 West Markham, Little Rock, AR 72205

               Himansu Javahar Vyas
U.S. Vanadium, Strategic Mineral Technology Center, 4343
         Malvern Road, Hot Springs, AR 71901
Introduction
   EPA Method 525.2 employs ethyl acetate as the primary elution solvent
    for the extraction of SOCs (Synthetic Organic Compounds) in drinking
    water by solid phase extraction (SPE).
   Ethyl acetate replaced methylene chloride used in earlier versions of the
    method because it improved analyte recoveries. However, the use of
    ethyl acetate can greatly increase GC/MS instrument maintenance when
    performed with temperature programmable injections.
   The implementation of performance based methodology will allow
    modification of EPA methods.
   Phthalate acid esters (PAEs) and polyaromatic hydrocarbons (PAHs) are
    spiked into distilled water and extracted by SPE.
   The study uses a C-18 extraction disk with methylene chloride as the
    elution solvent. Spikes are extracted using C-18 disks only and C-18
    disks with pre-filters. Two pre-filters and C-18 disks alone are presented.
    Additionally, drying the disks with nitrogen gas is evaluated. The study
    shows that analyte recoveries are improved so that methylene chloride
    alone can be used as the elution solvent.
Objective
 This work compares modifications of EPA Method 525.2
 intended to improve analyte recoveries.

    Can methylene chloride be used as the extraction
     solvent?
    Do pre-filters improve extraction efficiency and
     reproducibility?
    Does nitrogen gas drying enhance analyte recoveries?
       Extraction Apparatus
   Samples are extracted using six station Empore Extraction
    Manifolds.
   Nitrogen gas is delivered to the manifold from the gas outlet of
    a liquid nitrogen tank. The gas line runs through a high purity
    line regulator to a manifold.
   From the manifold, the gas line steps down from a 1/4 inch
    line to 0.5 mM i.d. Teflon tubing which runs through the top of
    a cleaned empty tuna can.
   The tuna can closely fits over the top of the extraction funnel.
   The Teflon line is looped inside the can so that the gas flow is
    diffused and does not directly blow onto the surface of the
    extraction disk.
Zymark      Acenaphthene-d10    Phenanthrene-d10     Chrysene-d12
Spike #     % Recovery          % Recovery           % Recovery

  1                89                  97                  97
  2                95                  99                  103
  3                100                 97                  104
  4                100                 104                 106
  5                94                  102                 107
  6                94                  101                 107
  7                94                  101                 104
  8                94                  101                 103
  9                99                  103                 105
  10               98                  101                 100
  11               98                  100                 105
  12               92                  96                  101
  13               95                  100                 103
  14               94                  103                 105
  15               91                  98                  104
  16               96                  104                 111
  17               98                  98                  106
  18               94                  102                 111
  19               98                  103                 104
  20               92                  103                 107
              Mean 95             Mean 101            Mean 105
          Std Dev              Std Dev             Std Dev
Whatman GMF Filter & Empore Disk vs. Plain Empore Disk
Drinking Water Matrix Samples-8 Minutes Ambient Air Drying

   Data       Acenaphthene-d10      Phenanthrene-d10         Chrysene-d12
   Name          % Recovery           % Recovery              % Recovery
             Whatman      Empore   Whatman      Empore   Whatman      Empore
             GMF Filter    Disk    GMF Filter    Disk    GMF Filter    Disk

    2757        97         66         98         76        104         83
    2759        68         72         70         77         79         84
    2760        96         84         92         88         96         86
    2761        94         83         95         88        102         89
    2762        92         78        100         84        107         85
    2763        93         79         96         83        105         85
    2764        94         87        101         89        110         91
    2765        87         79         93         85        101         86
    2766        94         92        102         92        105         90
    2767        90         74         97         80         94         76
     Mean       91         79         94         84        100         86
   Std Dev      8.0        7.2        8.7        5.0       8.4         4.0
PAE and PAH % Recovery- - - - - Laboratory Fortified Blanks
 Whatman GMF Filter and Empore Disk - - - Ambient Air Drying
                                                                                          Avg STD
ANALYTE                      #1    #2    #3    #4    #5    #6    #7    #8    #9    #10
                                                                                         % rec. Dev
Naphthalene                  100    91   101    99    85    88   101    99    89    90     94   5.9
Dimethyl phthalate           109   105    96   110   103   100   104   111   111   115    106   5.5
Acenaphthylene                99    90   101    98   103    99    96   101    75    88     95   8.1
Acenaphthene                  99    98   103    95    85    97    99   100    95    95     97   4.6
Diethyl phthalate            126   126   110   109   113   114   121   118   124   133    119   7.5
Fluorene                     106   105   102   105   105    95   103   102    97   110    103   4.1
Phenanthrene                 104   102   102    98   101    96   100   104    95    93    100   3.6
Anthracene                   103   107   105   108   108   105   111   106    97    91    104   5.6
Di-n-butyl phthalate         109   116   109   113   113   114   109   112   108   108    111   2.7
Fluoranthene                 103   105    97    98   107   105    94    97    98    95    100   4.4
Pyrene                       105   112   101   102   104   102   96    98    100   98     102   4.3
Butylbenzyl phthalate        108   116   97    108   108   105   105   113   100   114    107   5.7
Bis(2-ethylhexyl) adipate    78    106    93    93   100   109    95   92    102   105     97   8.6
Benzo[a]anthracene           98    101   100   110    96    99    93   97     93    94     98   4.8
Chrysene                     98     98    97    93   102    97   102   99     95   101     98   2.8
Bis(2-ethylhexyl)phthalate   87     92    96   103    98   102   117   97    109   115    102   9.2
Di-n-octyl phthalate         87    101    82    99   107   114   102   79     90   102     96   10.7
Benzo[b]&[k]fluoranthene     93     98    95    95    97    96    97   94     90   101     96   2.8
Benzo[a]pyrene               95     97    99   103    98   101    96   89     90    88     96   4.9
Indeno[1,2,3-cd]pyrene       87     94    88    89    89   101    96   78     81    99     90   7.0
Dibenzo[a,h]anthracene       75     84    81    80    81    74    88   67     73    78     78   5.7
Benzo[g,h,i]perylene         84     80    85    80    94    95    90   63     83    78     83   8.7
Sample Concentration Using a                        A “helical flow” of
                                                    air is created by the
Zymark TurboVap II                                  stream of gas
                                                    directed into each
                                                    sample tube.
To evaluate analyte loss in the concentration
step, internal standards are spiked directly into
25 mL methylene chloride in a 50 mL TurboVap
tube and concentrated to the 1 mL mark using
the sensor endpoint setting.
Instrumentation
    Varian Saturn II Mass Spectrometer
    Varian Star 3400 GC with SPI Injector
    Varian 8200 Autosampler



Solid Phase Extraction
Materials Evaluated
    3M Empore™ Octadecyl (C-18) Extraction Disks
    3M Empore™ Filter Aid 400 High Density Glass
     Beads
    Whatman ® Glass Microfiber (GMF) Filters, 2 um
Nitrogen Gas Drying - - Empore Disk and Whatman GMF Filter

                              Manifold
                                                 Tuna Can


                  Regulator


                                               Glass Funnel
     Gas Tank


                                            Aluminum Clamp

                                         Whatman GMF Filter

                                               Empore Disk

                                             Support Screen

                                              PTFE Gasket


                                                      Glass
                                               Support Base
  Empore Disk and           Empore Disk       Empore Disk
 Whatman GMF Filter                           and Filter Aid


                                             Glass
    Glass                Glass              Funnel
   Funnel               Funnel

Aluminum                                  Aluminum
   Clamp              Aluminum               Clamp
                         Clamp
 Whatman                                   Filter Aid
GMF Filter             Empore
  Empore                 Disk              Empore
     Disk                                    Disk
                       Support
  Support               Screen             Support
   Screen                                   Screen
   PTFE                  PTFE                PTFE
   Gasket               Gasket              Gasket

   Glass                 Glass             Glass
  Support               Support           Support
    Base                  Base              Base
Acenaphthene-d10 Recovery
Whatman GMF Filter & Empore Disk vs. Empore Disk
Ambient Air Drying
              120


              100
 % Recovery




               80


               60

                                    Whatman GMF + Empore Disk
               40

                                    Empore Disk
               20


                0
                    1   2   3   4   5     6       7     8       9   10
Chrysene-d12 Recovery
Whatman GMF Filter & Empore Disk vs. Empore Disk
Ambient Air Drying
        120

        100

             80
% Recovery




             60

             40                       Whatman GMF + Empore Disk

                                      Empore Disk
             20

              0
                  1   2   3   4   5       6         7    8        9   10
Phenanthrene-d10 Recovery
Whatman GMF Filter & Empore Disk vs. Empore Disk
Ambient Air Drying
          120


          100
 % Recovery




              80


              60


              40                       Whatman GMF + Empore Disk

                                       Empore Disk
              20


               0
                   1   2   3   4   5    6      7      8      9     10
Acenaphthene-d10 Recovery

             105



             90
% Recovery




             75
                                   Empore Disk
                                   Empore Disk & Filter Aid

             60                    N2 Drying 5 min, 20 psi Whatman GMF & Empore Disk
                                   N2 Drying 5 min, 30 psi Whatman GMF & Empore Disk
                                   N2 Drying 8 min, 25 psi Whatman GMF & Empore Disk
                                   N2 Drying 8 min, 30 psi Whatman GMF & Empore Disk

             45
                   0   2   4   6            8                 10                12
Phenanthrene-d10 Recovery

             105


              90
% Recovery




              75
                                   Empore Disk
                                   Empore Disk & Filter Aid
                                   N2 Drying 5 min, 20 psi Whatman GMF & Empore Disk
              60
                                   N2 Drying 5 min, 30 psi Whatman GMF & Empore Disk
                                   N2 Drying 8 min, 25 psi Whatman GMF & Empore Disk
                                   N2 Drying 8 min, 30 psi Whatman GMF & Empore Disk

              45
                   0   2   4   6             8                10                 12
Chrysene-d12 Recovery

         105



             90
% Recovery




             75

                                  Empore Disk
                                  Empore Disk & Filter Aid
             60                   N2 Drying 5 min, 20 psi Whatman GMF & Empore Disk
                                  N2 Drying 5 min, 30 psi Whatman GMF & Empore Disk
                                  N2 Drying 8 min, 25 psi Whatman GMF & Empore Disk
                                  N2 Drying 8 min, 30 psi Whatman GMF & Empore Disk

             45
                  0   2   4   6            8                 10                12
Average Internal Standard
% Recovery Comparison

  Acenaphethene-
       d10


   Phenanthrene-
       d10



    Chrysene-d12


                   0    20          40         60          80         100
                       Whatman GMF & Empore Disk
                       N2 Drying, 8 min/25 psi Whatman GMF & Empore Disk
                       N2 Drying, 8 min/30 psi Whatman GMF & Empore Disk
                       Filter Aid and Empore
                       Empore Disk
                       N2 Drying, 5 min/20 psi Whatman GMF & Empore Disk
Conclusions
    Very little analyte loss occurs in the concentration step.
    Nitrogen gas drying does not significantly improve
     recoveries
    Extraction with the Empore disk produces excellent
     recoveries for the internal standards in laboratory fortified
     blanks.
    Extraction with Filter Aid and the Empore disk produces
     inconsistent and low internal standard recoveries for
     laboratory fortified blanks.
    Internal standard recoveries are improved and are most
     consistent for drinking water matrices extracted with the
     Whatman GMF filter and the Empore disk.
    PAE and PAH recoveries are excellent for laboratory
     fortified blanks extracted with the Whatman GMF filter and
     the Empore disk.

								
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