中空纤维膜液相微萃取-GC-MS测定水果和蔬菜中三唑类杀菌剂残留量

研究了一种直接快速测定水果和蔬菜等固体样品中5种三唑类杀菌剂残留量的新方法,以气相色谱-质谱联用技术为基础,利用中空纤维膜液相微萃取提取固体样品中目标物。通过实验确定最佳萃取条件为：萃取剂为环己烷,固体样品与水的比例为1：3（总质量为10g）,超声震荡5min后以500r/min的搅拌速率在40℃下萃取20min。萃取后取1μL有机溶剂直接进样进行气相色谱质谱分离检测。在此条件下,水果和蔬菜中的三唑酮和多效唑的线性范围为0.5—25mg/kg,腈菌唑、烯唑醇和丙环唑的线性范围为1—25mg/kg;5种目标物的检出限均低于0.210mg/kg;相对标准偏差在4.7%—8.1%之间。该方法可以用于水果和蔬菜等固体样品中三唑类杀菌剂的快速测定。

Analysis of Triazole Fungicides Residues in Fruits and Vegetables by Hollow Fiber-Protected Liquid Phase Microextraction-Gas Chromatography-Mass Spectrometry

A new method for the rapid and direct measurement of triazole fungicides residue in fruits and vegetables was developed based on gas chromatography-mass spectrometry（GC-MS） with hollow-fiber protected liquid phase microextraction（HF-LPME） for the extraction of triazole fungicides in fruits and vegetables.The optimum extraction conditions were investigated：cyclohexane was selected as extract agent,solid samples/water ratio was 1：3（with a total quality 10g）,solid samples were extracted at 40°C for 20min with 500 r/min stirring rates after ultrasonic 5min.After extraction,1μL organic solvent was injected into GC-MS for separation and detection.Under the optimum conditions,linear range was 0.5—25mg/kg for triadimenfon and paclobutrazol,and 1—25mg/kg for myclobutanil,diniconazole and propiconazole;the limits of detection（LOD） were lower than 0.210mg/kg;the relative standard deviation（RSD） was in the range of 4.7%—8.1%.The method is fast and accurate for the determination of trace amounts of triazole fungicides in fruits and vegetables.