摘要
Abstract
[Objective]A detection method based on modified dispersive solid-phase extraction with carbon nanomaterials(QuEChERS)to improve the cleanup effect and combined with gas chromatography-triple quadrupole tandem mass spectrometry(GC-MS/MS)for the simultaneous determination of 31 pesticide residues in tea was developed.[Method]The tea samples were pulverized uniformly and purified by the modified QuEChERS method using carbon nanotubes as adsorption and purification fillers,and the pesticide residues in tea were extracted using a fully automated QuEChERS sample pretreatment system and quantified by GC-MS/MS external standard method.The purification effects of three types of single-walled carbon nanotubes(SWCNTs),multi-walled carbon nanotubes(MWCNTs)and aminated multi-walled carbon nanotubes(MWCNTs-NH2)were compared with each other and in different amounts.[Result]In this study,aminated multi-walled carbon nanotubes(MWCNTs-NH2)were finally selected to improve the traditional QuEChERS filler,and the limits of detection(LODs)of this research method were 0.02～1.68 μg·kg-1,and the limits of quantification(LOQs)were 0.05～5.61 μg·kg-1;The average recoveries of the target compounds at the three levels of spiked recoveries,low,medium and high,were 81.0%～119.7%with the relative standard deviation(RSD)ranging from 1.1%to 10.0%.The target pesticides showed different degrees of matrix effects in tea,and four target pesticides,such as chloroanisole,showed matrix inhibitory effects,while 27 target pesticides,such as lecithromycin,showed matrix-enhancing effects.[Conclusion]The method is automatic and efficient,with high sensitivity,the whole process consumes less time,can effectively save labor costs,and is suitable for the detection of larger batches of tea samples.关键词
碳纳米管/QuEChERS/农药残留/净化/茶叶/气相色谱-三重四级杆串联质谱Key words
Nanocarbon tubes/QuEChERS/pesticide residues/purification/tea/gas chromatography-triple quadrupole tandem mass spectrometry分类
农业科技
