测定食品中甲醛的样品前处理方法比较

Comparison On The Pretreatment Method Of Formaldehyde In Food

目的对测定食品中甲醛的四种样品处理方法进行比较,并对超声提取法的提取时间进行优化试验。方法用乙酰丙酮分光光度法。结果乙酰丙酮分光光度法简便,适应于大批量样品的测定。样品的前处理方法:直接蒸馏法和水蒸气蒸馏法的测定值差异无统计学意义,其中以水蒸气蒸馏法为最佳;而超声提取法和水浸泡法的测定结果则偏低,但更简单、快速,而且测定的只是游离甲醛,这对于在食品中添加甲醛或用甲醛水溶液浸泡食品,是很实用的。由超声时间实验,认为超声提取8min～10min为宜。结论实验发现,测定不同类别食品中的甲醛,样品处理应选用不同的方法,才能获得样品中的真实含量。

Objective to compare the four kinds ofpretreatment methods of formaldehyde in food, and to do an optimization tests on the extract time of the method of Ultrasonic extraction. Method the Acetylacetone Spectrophotometry Results Acetylacetone Spectrophotometry is simple and it can be well used to measure batches of food samples. The pretreatment method of the food samples： There are no significant differences between the results of the Direct Distillation and the Stream Distillation, but it is better to choose the latter. The method of Ultrasonic extraction and Immersion in water, with the character of simpler and higher-speed, are practical for the food with formaldehyde or the immersed food by formaldehyde because they just measure the freeformaldehude in the food. According to the ultrasonic test, the best extraction time is between 8min and 10min. Conclusion The tests display in order to get the exact content of formaldehyde in the food sample, we should choose different methods for different kinds of food.