单滴微萃取技术测定饲料中硝基咪唑类药物残留研究

Determination of Nitroimidazoles Residue in Feed Samples with Single-drop Microextraction

建立了单滴微萃取(SDME)与气相色谱-质谱(GC-MS)联合应用技术用于快速检测饲料中的硝基咪唑类药物,对影响萃取的因素进行优化。优化的萃取条件为:溶剂为2.5μL正辛醇,温度为50℃,搅拌速度为600r/min,时间为20min。萃取后,微液滴于70℃衍生45min,进样分析。该方法线性范围为0.5～400ng/mL,线性关系良好(r2>0.9960),检测限为0.16～0.57ng/mL。在饲料中的相对平均回收率为86.8%～103.6%,相对标准偏差为1.7%～7.5%。与传统方法相比,单滴微萃取所需的有机溶剂量很小,是一种快速、简单、安全、有效的检测饲料中硝基咪唑类药物残留的方法。

In this paper, detecting nitroimidazoles in feed by single drop microextraction （SDME）conjunction with gas chromatography-mass spectrometry was successfully developed.Some important factors （nature of organic solvents, microdrop volume, extraction time and stirring rate） affecting extraction efficiency were investigated and optimized separately.Optimal experiment was extracted with 2.5μL n-octyl alcohol in 50℃ for 20 minutes at 600 r/min.After extraction, the microdrop was derivated for 45min in 70℃ and directly analyzed by gas chromatography-mass spectrometry （GC-MS）.The limits of detection （LOD） in water for the four studied compounds were between 0.16 and 0.57ng/mL.The linearity of the method was in the range of 0.5～400 ng/mL with a good correlation coefficient （r^2〉0.996 0）.The recoveries in feed were from 86.8% to 103.6% with the relative standard deviations ranging from 1.7% to 7.5%.Compared with the conventional methods, the proposed method was a rapid, simple, safe and available one for detecting nitroimidazoles in feed.