Document 4ajZz4nJBkazKJY485O1rzxyQ

w Institute of Anal Leal Chemistry Univoreity of Stockholm 104 05 Stockholm 50 CJ To OECD Study of Pesticide Residue 1967-68 Results obtained by analysis of the OECD exchange samples 1, 3 and 4, Sample No 1. (standard prepared in Holland) The sample was dieted 200 times with petroleum ether (b.p. 60-70C), and 5 to 10^ul aliquots were injected into the gas chromatograph (Varion Aerograph 204). The stationary phase was a mixture (modified as below) of SP-96 and QP-1 (l:3)| 5 % total coating on silanized Qas Chrom P (100-120 mesh). The column (glass) length 150 cm; l.d. 1,8 mm) was prepared by blending in small portions of the two coatings. After conditioning the column for 24 h or more the flow of carrier gas was adjusted (usually 25-28 ml/mln) to give air a retention time of 13 sec. The temperature of the column was selected (usually 180- 190C) to give pplllT a retention time of 20.0 minutes. The preliminary analyses of sample No 1 showed the presence of the following pesticides, eluted in the order given and separated almost totally on the column used: '' Heptachlor epoxide, ppDBE, Dieldrin, Endrin, ppITOD and ppDPT. The two pesticides, Heptachlor epoxide ar.d Endrin, are not in common use in Sweden, and thus a separate analytical investigation was performed at this institute. Endrin was found to dec;-pose on the stationery phase described, and Heptachlor epoxide gave irreproducible results. Addi tional impregnation of the stationary phases,,(with 0.17 % Epikote 1001) woe found to result in a sufficient deactivation demonstrated by studies of recovery of Endrin. A simple change of or. old reference standard of Heptachlor epoxide was sufficient to give acceptable analytical results for this compound. Seven analyses of the sample No 1 gave the following result, reported as ng/ml of the undiluted solution delivered. HONE 045744 l I HONS 0 4 5 7 4 5 Sample No 1 Heptacblor epoxide pp DDE Dieldrin Endrin pp DKD pp BBT nj/ml mean valUe 3800 5100 5500 6600 10400 10200 mean deviation 2. 300 1 200 + 300 t 300 + 500 Further qualitative analyses were made by separate Injections of the sample on SP-96 or QF-1 columns, and after pre-treatment of the sample with fuming sulphuric acid and potassium hydroxide respectively. Ko indications were found for the presence of compounds other than those reported. 2. Sample Mo 3 (ood liver oil from Scotland) Since this sample contains PCB compounds a direct method has been chosen for this study. However, this method only allows the detection of very stable compounds and all oxygen containing pesticides are de composed at the cleaning up stage of the method. Procedure: 200 mg of the oil were dissolved in 5 ml of hexane and shaken for 1-2 minutes with a 1 ml of mixture (l:l) of cone sulphuric acid and fuming sulphuric acid (fuming sulphuric acid; 10 # 50^). The organic phase,.after being washed and then dried, was injected into the column described. The above mentioned columns gave reasonably good resolution of the following peaks of PCB": 2,3,5*6,10,11,12,13 and 14 None of these coincided with any pesticide peak found in the sample. Among the pesti cides we were able to detect, ppDDE and ppBDT do not interfere with any of tho PCB peaks, but ppBDB overlaps PCB 9, a minor component. The peaks of opDDT and PCB 7 also overlap, as well aa those of opDDD and PCB 6. However, the last two generally appear as very small peaks which con be neglected (but not in this samplel) The usually-obtained pattern of PCB residue analysis, especially the relation of the height of pecks 7, 8 and 10, leads us to assume that in this sample half of the peak in the position of PCB 7 is given by opDDT. A quantitative estimation of the amount of Dieldrin present in sample Mo 5 was separately made by measurement of the difference in peak heights between chromatograms of an extract cleaned-up by acetonitrile - petroleum ether partition and chromatograms of the same extract after treatment with the acid mixture discussed Sample No 3 ' Results given In ng/g ood liver oil as delivered Stable pesticides pp DDE OP I)DD pp DEC op EOT pp DOT Dleldrln 400 240 (PCB interference) 490 65 (the rest of the peak reported as PCB 550 90 PCB 2 2' 3 5 7 s 9 10 80 90 260 70 85 140 140 obscured by ppDDD 11 13 . 14 90 60 _52 (1065) 1100 ng/g Sample No 4 (Sample of egg prepared In Holland) A portion (0,5 g) of egg powder in the ampoule was shaken (15 minutes) In o stoppered test tube together with 10 ml of a hexane-benzene mixture (l:l), After standing overnight the tube was shaken again and then centrifuged. The extract was Injected without further treatment into the column previously described. Sample No 4 DDE Dleldrln Endrln pr DDD pp DDT ng/g (ppb) mean value 34.1 44*1 39.1 4.0 103.0 mean deviation + 1.4 i 2'3 + 1.3 - " 1#0 MONS 045746 l 4.6 Stockholm 28/2 1969 Sbren Jensen '!(/u Co (Kruno Nucci y/< Keratin Widwark,