Lawrence J F, Wong B
Health Protection Branch, Food Research Division, Ottawa, Canada.
J AOAC Int. 1995 May-Jun;78(3):698-704.
A liquid chromatographic method using a postcolumn electrochemical reactor that oxidizes paralytic shellfish poison toxins to fluorescent derivatives has been developed. Several experimental parameters, including pH and oxidation potential, were investigated. For nonhydroxylated toxins, the sensitivity improved with increasing pH and voltage. At optimum operating conditions, the sensitivity for saxitoxin and gonyautoxins 2 and 3 was an order of magnitude greater than that for neosaxitoxin and B1 and 2 orders of magnitude greater than that for B2. The limit of detection for saxitoxin was 0.10 ng (signal-to-noise ratio, 3:1). Electrochemical oxidation products were similar to those formed in the prechromatographic periodate oxidation method. Shellfish and plankton extracts were analyzed with the electrochemical system, and results agreed well with those obtained with established methods. Shellfish samples contaminated at the regulatory limit of 0.8 microgram/g were readily analyzed by the method.
已开发出一种液相色谱方法，该方法使用柱后电化学反应器将麻痹性贝类毒素氧化为荧光衍生物。研究了几个实验参数，包括pH值和氧化电位。对于非羟基化毒素，灵敏度随着pH值和电压的增加而提高。在最佳操作条件下，石房蛤毒素以及膝沟藻毒素2和3的灵敏度比新石房蛤毒素和B1高一个数量级，比B2高两个数量级。石房蛤毒素的检测限为0.10纳克（信噪比为3:1）。电化学氧化产物与在色谱前高碘酸盐氧化法中形成的产物相似。用电化学系统对贝类和浮游生物提取物进行了分析，结果与用既定方法获得的结果非常吻合。该方法能够轻松分析受0.8微克/克监管限值污染的贝类样品。
