Quantitative determination of aflatoxin in groundnut products
Quantitative determination of aflatoxin in groundnut products
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花生制品中黄曲霉毒素的定量测定
DOI：
10.1039/an9659000305
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发表时间：
1965
期刊：
影响因子：
--
通讯作者：
W. V. Lee
中科院分区：
文献类型：
--
作者：
W. V. Lee
检查动物饲料原料中是否含有黄曲霉毒素（一种与一些花生产品有关的毒素）需要花费大量时间和精力。迫切需要一种方法，使黄曲霉毒素的测定能够以一种简单和快速的方式进行。简而言之，它涉及到在实验室温度下，在有水存在的情况下，用氯仿从磨碎的面粉中提取毒素。在不到1小时的时间内就可以对一顿去脂餐进行测定。毒素量的评估是通过使用Kieselgel G薄层色谱板进行的，如已发表的文献。以前从米饭中提取毒素的方法是用有机溶剂长时间煮沸。提取的缓慢被认为是由于毒素的保护，可能是蛋白质复合物或细胞结构的性质。人们认为有必要以某种方式改变结构，以使毒素能够被溶解。人们发现，当水加入到食物中时，会发生肿胀，这足以使毒素在氯仿中迅速溶解。根据《肥料和饲料法》的规定，对一种有毒的花生粕进行纤维检测时发现，酸性滤液中含有大部分黄曲霉毒素，而且很容易用氯仿从酸性水中提取黄曲霉毒素。从这一事实出发，许多提取都是在氯仿存在的情况下，用冷热、弱酸性和弱碱性溶液以及水进行的。采用传统的甲醇萃取技术对不同毒性的膳食进行测定。结果发现，水（为了保持稠度而使用蒸馏水）的作用方式与酸性和碱性溶液相似，随后又进行了进一步的试验。在早期的实验工作中，大多数试验都是这样进行的：将10或20克的脱脂粉放入一个容量为200至250毫升的瓶子中，并向瓶子中加入相当于10倍于脱脂粉重量的冷水。然后摇晃肿块直到它完全湿润，之后反复翻转瓶子摇晃30分钟。然后加入50或100毫升氯仿，再重复摇晃10分钟。氯仿通过离心或分离漏斗回收，然后用薄层色谱法直接在该溶液中测定黄曲霉毒素，如已发表的文献。结果表明，水-氯仿法与任何一种冗长的甲醇法所得结果一致。有时前者产生的结果稍高一些。
THE examination of raw materials used in animal feeding stuffs for the presence of aflatoxin, a poison associated with some groundnut products, takes much time and effort. The pressing need has been for a method that would permit a determination of aflatoxin to be carried out in a simple and speedy manner. Briefly, it involves the extraction of the toxin from the ground meal by chloroform in the presence of water at laboratory temperatures. A determination can be carried out on a de-fatted meal in less than 1 hour. The assessment of the amount of toxin is made by using thin-layer chromatographic plates of Kieselgel G, as in the published literature.'v2r3 v 4Previous methods for extracting the toxin from the meal involved prolonged boiling with organic solvents. The slowness of the extraction was thought to be because of protection of the toxin, perhaps by a protein complex or by the nature of the cell structure. It was thought necessary to change the structure in some way so as to permit the toxin to be available for solution, and it was found that the swelling that takes place when water is added to the meal causes sufficient disruption for rapid dissolution of the toxin in chloroform to occur. It was found, when a toxic groundnut meal was tested for fibre by the method of the Fertiliser and Feeding Stuffs Act, that the acid filtrate contained most, if not all, of the aflatoxin, and that it was readily extracted from the acidic water by chloroform. Starting with this fact, many extractions were carried out with hot and cold, faintly acidic and alkaline solutions, and water, in the presence of chloroform. Meals of varying toxicity, on which determinations by the conventional methanol-extraction techniques had been made, were used. It was found that water (distilled was used for the sake of consistency) proved to act in a manner similar to the acidic and alkaline solutions, and was subsequently used in further tests. In the early experimental work most of the tests were carried out as described below-A 10-or 20-g portion of the ground, de-fatted meal was put into a bottle of 200 to 250-mlcapacity to which was added cold water, equivalent to about ten times the weight of the meal. The mass was then shaken until it was completely wetted, after which it was shaken by repeatedly inverting the bottle for 30 minutes. Chloroform, 50 or 100 ml, was then added and the shaking repeated for a further 10 minutes. The chloroform was recovered either by centrifugation or by means of a separating funnel, after which the aflatoxin was determined directly in this solution by thin-layer chromatography as in the published literature. It was found that the results obtained by the water-chloroform method were in agreement with those obtained when any of the lengthy methanol methods was used. Occasionally the former yielded slightly the higher results.