Comparative study of methodologies for the analysis of PCDDs and PDCFs in powdered full-fat milk. PCB, PCDD and PCDF levels in commercial samples from Spain.
Feasibility of two different extraction methods involving solid-liquid extraction and Soxhlet extraction, previously used for the determination of lipid contents and PCB levels on powdered full-fat milk, are now examined for simultaneous PCDD/F analysis. The results of this study are consistent with those found for PCBs. The solid-liquid procedure provides the most efficient extraction of both labelled spiked and endogenous PCDD/Fs with the lowest variability. The average recoveries were 101% (R.S.D. = 6.9%) for 13C12-2,3,7,8-TCDD and 95% (R.S.D. = 11%) for 13C12-1,2,3,4,7,8-HxCDD. The R.S.D.s for endogenous 2,3,7,8-PCDD/Fs were in the 9.3-25% range. In addition, this methodology simplified the subsequent clean-up step as it allowed a semi-selective extraction of the apolar lipids from the milk. The proposed method was applied to simultaneous PCB and PCDD/F analyses in different brands of powdered full-fat milks commercially available in Spain. In all cases, very similar PCB and PCDD/F levels were found. Differences among batches from the same manufacturer were even lower. The total i-TEQ average for PCDDs and PCDFs in the 22 powdered full-fat milk samples analysed was 1.87 pg/g fat basis. This value was similar to those found in cow's milk from other European countries.
Ramos
L
L
Department of I.A. and Environmental Chemistry, I.Q.O. (C.S.I.C.), Juan de la Cierva, Madrid, Spain.
Eljarrat
E
E
Hernández
L M
LM
Rivera
J
J
González
M J
MJ
D000818:Animals; D001572:Benzofurans / Q000032:analysis*; D000072338:Dibenzofurans, Polychlorinated; D004785:Environmental Pollutants / Q000032:analysis*; D008892:Milk / Q000737:chemistry*; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis; D013030:Spain
D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins; D011078:Polychlorinated Biphenyls