Scott P M, Yeung J M, Lawrence G A, Prelusky D B
Health Canada, Health Protection Branch, Ottawa, Ontario, Canada.
Food Addit Contam. 1997 Jul;14(5):445-50. doi: 10.1080/02652039709374550.
A recently developed sensitive indirect competitive enzyme-linked immunosorbent assay (ELISA) was applied to the determination of fumonisins in beer. Intra-assay and inter-assay recoveries averaged 98.7-102.8% at added fumonisin B1 (FB1) levels of 0.5-50 ng/ml beer, and coefficients of variation were 2.8-4.4 and 4.7-8.6%, respectively. Cross-reactivity of fumonisin B2 (FB2) compared with FB1 averaged 67% in beer. Two experiments were carried out to compare ELISA with liquid chromatography (LC) for determination of fumonisins in beer. In the first experiment, 19 samples (five previously known positive, nine other samples and five spiked samples) were passed through commercial immunoaffinity columns (ICs) and analysed by LC before conducting blind ELISA determinations on the extracts and beers directly. The known positive beers and extracts were used as blind duplicates. The second comparative experiment screened 46 beer samples by ELISA and then 22 positive and three of the negative samples were analysed by LC; the highest level found was 64.3 ng total fumonisins/ml measured by LC (24.7 ng/ml by ELISA). Regression analyses showed good correlation between ELISA and LC in the first experiment but low level interferences (equivalent to up to 5.35 ng fumonisin/ml) were observed by ELISA in the IC extracts. Five of nine beers negative by LC showed < 1 ng/ml ELISA responses on direct beer analysis. The second comparative experiment indicated underestimation by ELISA. However, there were two samples which tested positive by ELISA (0.2 ng/ml) but were found negative by LC (results close to the detection limits of both methods, which were 0.1 or 0.2 ng/ml by ELISA and 0.1-0.15 ng each fumonisin/ml by LC). There were no false negatives. It is concluded that ELISA has considerable value in rapid screening of beer directly for fumonisins.
一种最近开发的灵敏间接竞争酶联免疫吸附测定法（ELISA）被应用于啤酒中伏马毒素的测定。在啤酒中添加伏马毒素B1（FB1）水平为0.5 - 50 ng/ml时，批内和批间回收率平均为98.7 - 102.8%，变异系数分别为2.8 - 4.4%和4.7 - 8.6%。伏马毒素B2（FB2）与FB1相比在啤酒中的交叉反应平均为67%。进行了两项实验以比较ELISA和液相色谱法（LC）用于测定啤酒中的伏马毒素。在第一个实验中，19个样品（5个先前已知的阳性样品、9个其他样品和5个加标样品）通过商用免疫亲和柱（ICs），并在对提取物和啤酒直接进行盲法ELISA测定之前通过LC进行分析。已知的阳性啤酒和提取物用作盲法重复样品。第二个比较实验通过ELISA筛选了46个啤酒样品，然后对22个阳性样品和3个阴性样品进行LC分析；通过LC测得的总伏马毒素最高水平为64.3 ng/ml（通过ELISA为24.7 ng/ml）。回归分析表明在第一个实验中ELISA和LC之间具有良好的相关性，但在IC提取物中通过ELISA观察到低水平干扰（相当于高达5.35 ng伏马毒素/ml）。通过LC检测为阴性的9个啤酒中有5个在直接啤酒分析中ELISA响应<1 ng/ml。第二个比较实验表明ELISA存在低估情况。然而，有两个样品通过ELISA检测为阳性（0.2 ng/ml）但通过LC检测为阴性（结果接近两种方法的检测限，ELISA为0.1或0.2 ng/ml，每种伏马毒素通过LC为0.1 - 0.15 ng/ml）。没有假阴性结果。结论是ELISA在直接快速筛选啤酒中的伏马毒素方面具有相当大的价值。
