毛细管电泳-量子点间接激光诱导荧光检测5种食品防腐剂

Determination of Five Preservatives in Food by Capillary Electrophoresis with Quantum Dot Indirect Laser Induced Fluorescence

以碲化镉量子点为荧光背景物质,建立了毛细管电泳-间接激光诱导荧光检测食品中对羟基苯甲酸丙酯、脱氢乙酸钠、山梨酸、苯甲酸和丙酸钠含量的方法,紫外吸收很弱的丙酸钠在本方法中显示为正峰,可被有效检出。研究了碲化镉量子点浓度、背景电解质浓度、pH值、分离电压对分析物峰高和迁移时间的影响。在最佳条件下,对羟基苯甲酸丙酯、脱氢乙酸钠、山梨酸、苯甲酸和丙酸钠在8.5min内得到分离,检出限分别为0.21,0.32,0.50,0.30和0.36mg/L,相对标准偏差分别为3.9%,2.1%,2.5%,1.9%和2.3%,平均加标回收率分别为96.8%,93.4%,96.3%,98.1%和99.1%。本方法的检出限及线性范围均优于文献报道结果,对食品中这5种防腐剂检测的结果与高效液相色谱法结果一致。

A new assay has been developed by use of capillary electrophoresis with indirect laser induced fluorescence using cadmium telluride quantum dots as fluorescent background substance to determine propylpareben, sodium dehydroaeetate, sorbic acid, benzoic acid and sodium propionate in food, in which the sodium propionate with weak UV absorption can be shown as positive peak and effectively detected. The effect of the parameters such as cadmium telluride quantum dot concentration, background electrolyte concentration, pH and separating voltage on the peak height and migration time of analytes have been studied. Under the optimum conditions, propylpareben, sodium dehydroacetate, sorbic acid, benzoic acid and sodium propionate can be separated within 8.5 min. Their detection limits were 0. 21, 0. 32, 0. 50, 0. 30 and 0. 36 mg/L, relative standard deviations 3.9%, 2.1%, 2.5%0, 1.9%0 and 2.3%, and average recoveries of spiked samples 96.8%, 93.4%, 96. 3%, 98. 1% and 99. 1%, respectively. The detection limits and linear dynamic ranges were better than those reported in the references, and the measurement results for the five preservatives in food by this assay have been proven by HPI,C.