Concentrations of polychlorinated dibenzo-p-dioxins, dibenzofurans and non-ortho substituted biphenyls in polar bear milk from Svalbard (Norway).

Polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and non-ortho substituted biphenyls (PCB, CB) were determined in 6 polar bear milk samples from Svalbard (Norway). For these compounds, no data for polar bears have been reported before from this region. Most of the PCDD/PCDF congeners were found at detectable levels. Concentrations expressed as 2,3,7,8-TCDD equivalents (Nordic model) were in the order of 1-3 pg/g(-1) fat (0.2-1.6 pg ml(-1) milk) which is comparable with ringed and harp seal blubber from the same region. On whole milk basis, concentrations were similar to those found in human milk. An estimation of the daily uptake via milk showed that the intake is lower for polar bears compared to humans. As in human milk, relatively high levels of OCDD were found in some polar bear milk samples. The PCDD/PCDF congener pattern in the milk was different to that found in polar bear fat from the Canadian Arctic. Non-ortho substituted PCB levels in polar bear milk were similar to those found in polar bear fat from the Canadian North. However, CB 77 or 169 dominated in the milk while CB 126 was the most abundant congener in fat. PCDD/PCDF levels expressed as 2,3,7,8-TE were highly correlated with the fat content of the milk. No correlation between CB and PCDD/PCDF concentrations was found. Some data indicate that PCDD/PCDF concentrations in polar bear milk decrease with increasing time after delivery.

Identification of opiates in urine by capillary column gas chromatography of two different derivatives.

A capillary gas chromatographic method is described for the identification and confirmation of morphine, codeine, ethylmorphine and 6-monoacetylmorphine in urine. The method was useful for forensic purposes, as morphine and 6-monoacetylmorphine could be measured together with the legal drugs codeine and ethylmorphine. The legal non-prescription drug pholcodine could be detected together with the metabolites normorphine and norcodeine. After extraction and evaporation the opiates were derivatized with either N,O-bis(trimethylsilyl)trifluoroacetamide or pentafluoropropionic anhydride, and both types of derivative were chromatographed on a non-polar capillary column with a nitrogen-phosphorus selective detector. The use of two chemically different derivatives was found to be necessary for the unequivocal identification of all opiates of interest, which were not all separated as a single derivative. If a mixture of opiates was subjected to the two different derivatization agents, the derivatives were eluted in a different order. This improved considerably the selectivity of opiate analysis in urine. Particularly difficult samples would require mass spectrometric confirmation.