Survey of Canadian human blood plasma for ochratoxin A

Abstract

Blood plasma samples collected from 144 healthy volunteers in 16 locations across Canada in 1994 were analysed for ochratoxin A (OTA). The method of analysis included cleanup by C₁₈ solid phase extraction and immunoaffinity columns followed by liquid chromatography (LC) with fluorescence detection, which gave 86.5% (s.d. = 9.7) recovery (n = 31) of OTA (added at 2 ng/ml) with a detection limit of 0.15ng/ml. The arithmetic mean concentration found in the plasma samples, corrected for volume of anticoagulant added, was 0.88 ng/ml with a standard deviation of 0.35ng/ml and a range of 0.29–2.37 ng/ml. Confirmation of identity of OTA was by methyl ester formation for 65 samples and by LC‐tandem mass spectrometry for 17 samples (some of which were included in pooled samples). Statistical analysis, by ANOVA of the log OTA plasma concentrations, showed a highly significant effect due to location in Canada (p =<0.0001) but no effect due to age, sex or blood group of donors. The highest mean concentration was found in Winnipeg, significantly different (p = 0.05) by the Student‐Newman‐Keuls multiple range test from the lowest levels found in Toronto, Vancouver and Saint John.

Keywords:

• ochratoxin A
• mycotoxin
• human exposure.

Notes

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