NOTE: For greater accuracy in oil analysis, weigh 

 accurately about 2.0-2.5 g oil into a 25-ml vol- 

 umetric flask. Dilute to volume with hexane. 

 Shake thoroughly. Place sample in storage bottle 

 and proceed at step 9 under Cleanup. 



Paper 



This procedure is included because occasionally 

 fishery samples come in contact with contami- 

 nated packaging and labelling materials, such as 

 carbonless carbon paper and cardboard. Although 

 the procedure has not been validated by collabora- 

 tive studies, it provides guidelines for an analysis 

 relevant to fishery studies. 



Cut the paper (or cardboard* into small pieces, 

 approximately 1 cm on a side, with a scissors or 

 office paper cutter, which has been cleaned 

 thoroughly with iso-octane or hexane. Mix the 

 paper thoroughly and weigh ca. 7 g into a Virtis 

 flask. Add 15 ml distilled water and mix 

 thoroughly with the paper. Allow the mixture to 

 stand 2-5 min, stir again, and dilute with portions 

 of 1:1 IPA/benzene to a total of 70 ml. Homogenize 

 the mixture briefly at low speed. Push the paper 

 down with the Virtis blades, then homogenize 

 briefly. Repeat the process until the paper is com- 

 pletely homogeneous, approximately 10 min total 

 homogenization time. Follow the usual boildown 

 and Florisil procedures. 



Proccdiiri.' For Dieldrin and Kndrin 



Saponification'' and Extraction 



1) Weigh 10 g of material to be analyzed into a 

 250-ml Erlenmeyer flask. For oil, use only 2 g. 



2) Dissolve 10 g of KOH in 6 ml distilled water. 

 Slowly dilute with 34 ml of ethyl alcohol (95 or 

 100%). Swirl until clear. 



3) Pour the alcoholic KOH over the sample and 

 heat in a water bath without boiling for 20 min; 

 the exact temperature is not critical. 



4) Allow the mixture to cool. Pour the liquid 

 portion into a 250-ml separatory funnel and rinse 

 out the Erlenmeyer flask with 50 ml of water, 

 divided into 4 or 5 portions. Avoid pouring any 

 solids into the separatory funnel. For finely pow- 

 dered samples like meal, filter the sample through 



^Saponification in the pre.sence of some proteinaceous mate- 

 rials has been reported to cause degradation of dieldrin. As 

 stated above, recovery studies are always important. 



a wad of glass wool and rinse the glass wool care- 

 fully with each rinse. 



5) Add 15 ml hexane to the separatory funnel 

 and shake for 2 min. Open the stopcock several 

 times during shaking to relieve the pressure 

 buildup. Allow the layers to separate completely, 

 usually about 30 min. 



6) Drain off the aqueous layer into the Erlen- 

 meyer flask from which it came. Pour the hexane 

 layer into a 30-ml beaker. Do not let any water 

 escape into the beaker. Cover the beaker tightly 

 with aluminum foil. 



7) Pour the aqueous layer back into the 

 separatory funnel and repeat step 5. 



8) Drain off the aqueous layer and discard it. 



9) Return the hexane extract in the beaker to 

 the separatory funnel. Rinse the sides of the 

 beaker with 1 ml hexane. Add the hexane wash to 

 the extract in the separatory funnel. 



10) Wash the hexane extract with 10 ml water 

 by rotating the separatory funnel gently to avoid 

 emulsion formation. Do not shake. Allow the 

 layers to separate and discard the aqueous layer. 



11) Pour the hexane layer into a 50-ml 

 graduated cylinder. Do not transfer any water to 

 the cylinder. Record the volume. Pour the extract 

 into a 23-ml borosilicate screw-cap bottle (with 

 Teflon-lined cap) containing 1 g NagSO^. 



Cleanup 



12) Prepare a Florisil column by filling a 9 mm 

 i.d. X 150 mm glass tube, plugged with glass wool, 

 with ca. 4 cm of Florisil. Or use a 7 mm i.d. x 150 

 mm tube containing ca. 5 cm of Florisil. (The 

 longer column of adsorbent may give slightly bet- 

 ter cleanup.) Wet the Florisil with benzene and 

 wash it with 4 to 5 ml benzene added 1 ml at a time. 

 Wash it next with 10 ml hexane (or more) added 1 

 ml at a time. Pipette 2 ml of the hexane extract 

 onto the column. Put a 12-ml graduated centrifuge 

 tube under the column. Flute with hexane added 1 

 ml at a time. Collect the first 12 ml of hexane 

 eluate, which contains DDMU (the dehydro- 

 chlorination product of TDE), DDE, and PCB. 

 (They may be quantitated if desired.) 



Place a second 12-ml centrifuge tube under the 

 column. Change eluant to benzene; add it 1 ml at a 

 time. Collect the first 10 ml of eluate. Place a 

 modified micro Snyder column on the centrifuge 

 tube to prevent loss of residues during evapora- 

 tion. Concentrate the eluate containing dieldrin 

 and endrin to an appropriate volume (1-3 ml) for 



885 



