气相色谱法测定豆芽中2,4-二氯苯氧乙酸残留量

Determination of 2,4-Dichlorophenoxyacetic Acid Residues in Bean Sprout by Gas Chromatography

豆芽在国内有着悠久的生产历史,它具有较高的营养价值,是一种深受广大消费者喜欢的食品。但近年来一些生产者为了缩短豆芽的生长周期,使豆芽变得嫩白、粗壮,在豆芽生产过程中添加了激素类植物生长调节剂,2,4-D就是其中一种。改进了现有的检测方法,用乙腈提取豆芽中的2,4-D,14%三氟化硼甲醇溶液进行衍生化,正己烷提取,气相色谱仪配HP-5型石英毛细管气相色谱柱,ECD检测器进行测定,能更加方便、快速和准确地测定豆芽中2,4-D的含量。结果表明,该方法具有良好的线性响应,相关系数为0.995~1.000,最低检出限为0.002 mg/kg,加标回收率为91%~103%。

Production of bean sprout has the centuries-old history in China. Bean sprout has high nutritional value, and is a very popular food. But recently, some producers added the hormones plant growth regulator in the production of bean sprout to shorten growth time and make it tender, white and thick, and 2,4-D is one kind of these growth regulators. Existing test meth- ods were improved, 2,4-D in bean sprout was distilled with methyl cyanide, derived with 14% boron trifluoride formaldehyde solvent, extracted with hexane, and detected by gas chromatography with HP-5 quartz capillary column and ECD detector. This determination could detect 2,4-D quantity in bean sprout more conveniently, rapidly and exactly. Results proved that this deter- mination has good linearity response, correlative coefficient was between 0. 995 and 1. 000, detection limit was 0. 002 mg/kg, and recovery for spiked standards was between 91% and 103%.