分散固相萃取净化气相色谱串联质谱法测定茶叶、西葫芦和芒果中噻螨酮和噻嗪酮残留量

Residue Determination of Hexythiazox and Buprofezin in Tea,Marrow and Mango by Gas Chromatography Coupled with Tandem Mass Spectrometry after Dispersive Solid Phase Extraction Cleanup

建立了分散周相萃取净化、气相色谱串联质谱法(GC-MS/MS)测定茶叶、芒果和可葫芦中噻螨酮和噻嗪酮残留分析方法,并对噻螨酮、噻嗪酮的质谱裂解规律和基质效应进行了分析。噻嗪酮和噻螨酮分别在0.040～40 mg/L和0.025～2.5 mg/L浓度范围内呈线性关系,相关系数0.9910,检出限分别为0.005和0.010 mg/L;不同样品中噻螨酮和噻嗪酮平均回收率为83.6%～116.9%之间,相对标准偏差为2.0%～15.7%,方法定量限为茶叶中0.010 mg/kg,西葫芦、芒果中为0.002 mg/kg采用此方法抽检我国不同地区市场上的120份芒果、西葫芦样品,均未检出噻螨酮噻嗪酮残留;检测20份噻嗪酮田间残留试验茶叶样,均未检出噻嗪酮残留(低于3.9 mg/kg)。

A novel and sensitive method was developed and validated for the simultaneous determination of hexythiazox and buprofezin residue in tea,mango and marrow using gas chromatography coupled with tandem mass spectrometry.Target compounds were extracted by acetonitrile followed by dispersive solid phase extraction cleanup.The fragmentation pathway and matrix effect were investigated. Over the concentration in the range of 0.040—4.000 mg/L for buprofezin and 0.025—2.5 mg/L for hexythiazox in different matrix,the correlation coefficients（r） of the calibration curves were above 0.9910,and the limits of detection（LODs） were 0.005 mg/L and 0.010 mg/L for each other.The average recoveries of hexythiazox and buprofezin in different matrix at three spiked concentration levels ranged from 83.6%to 116.9%with relative standard deviations（RSDs） between 2.0%and 15.7%（n = 5）.The limits of quantitation（LOQs） of hexythiazox and buprofezin,were 0.010 mg/kg in green tea and 0.002 mg/kg in marrow and mango sample.Then,the proposed method was successfully applied to the routine market monitoring of mango and marrow in different regions in China,there was no hexythiazox and buprofezin residue detected in the all of samples （n=120）;and it has also been applied to the residue analysis of buprofezin field test samples（n = 20） in tea garden,the residues of buprofezin were from not detected to 3.9 mg/kg.