Scott P M, Kanhere S R
Food Research Division, Health Canada, Ottawa, Ontario.
Food Addit Contam. 1995 Jul-Aug;12(4):591-8. doi: 10.1080/02652039509374347.
Because of concern about possible transmission of ochratoxin A (OA) from contaminated grain adjuncts, development of a sensitive method for its determination in beer was investigated. Solid phase extraction (SPE) on C-18 and silica gel columns in series and on an immunoaffinity column (OchraTest) were used to obtain extracts for quantitation by reverse phase liquid chromatography with fluorescence detection. The standard curve was linear in the range 2.5-50 pg OA injected and detection limits for both methods were of the order 0.05-0.1 ng/ml beer (signal to noise 3:1). Per cent recovery of OA from various beer samples spiked at a level of 1 ng/ml averaged 82-100% for three modifications of the SPE method and 97% for the immunoaffinity column method. Forty-one samples of Canadian and imported beers were analysed. Trace levels of OA (< or = 0.2 ng/ml) were detected in 26 samples by SPE and/or immunoaffinity column methods; there was generally good agreement between the methods. Identity of OA was confirmed by methyl ester formation in five samples cleaned up by the immunoaffinity column procedure.
由于担心受污染的谷物辅料可能会传播赭曲霉毒素A（OA），因此对开发一种用于测定啤酒中OA的灵敏方法进行了研究。串联使用C-18柱和硅胶柱以及免疫亲和柱（OchraTest）进行固相萃取（SPE），以获得提取物，通过带荧光检测的反相液相色谱法定量。进样2.5 - 50 pg OA时标准曲线呈线性，两种方法的检测限均为0.05 - 0.1 ng/ml啤酒（信噪比3:1）。对于添加水平为1 ng/ml的各种啤酒样品，SPE方法的三种改进方法中OA的回收率平均为82 - 100%，免疫亲和柱方法的回收率为97%。分析了41个加拿大啤酒和进口啤酒样品。通过SPE和/或免疫亲和柱方法在26个样品中检测到痕量水平的OA（≤0.2 ng/ml）；两种方法之间总体上具有良好的一致性。通过免疫亲和柱程序净化的5个样品中，通过甲酯形成确认了OA的身份。
