Study on QuEChERS isotope dilution ultra-high performance liquid chromatography-tandem mass spectrometry for simultaneous determination of eight pesticide residues,including cyromazine,in plant food
Objective To establish a QuEChERS isotope dilution ultra-high performance liquid chromatography-tandem mass spectrometry method for simultaneously determining eight pesticide residues,including cyromazine,in plant-based foods.Methods After weighing the sample,a mixed isotope internal standard was added,extracted by acetonitrile,sodium chloride and anhydrous sodium sulfate were added.After centrifugation,the supernatant was purified by ethylenediamine-N-propylsilanized silica gel(PSA),and determined by ultra-high performance liquid chromatography tandem mass spectrome-try(UPLC-MS/MS),and quantified by internal standard method.Results The correlation coefficients of eight pesticides within the concentration range of 0.5～100 μg/L were 0.992 2 to 0.999 8,the detection limit was 0.000 1 to 0.002 mg/kg,and the quantitative limit was 0.0003 to 0.007 mg/kg.After adding three spiked concentrations of 0.002,0.02,and 0.12 mg/kg,the average recovery rate of this method was 86.5％to 110.0％with the relative standard deviation of 1.40％to 9.80％.This method was applied to detect 30 samples of commercially available fruits and vegetables,and all eight pesti-cides were detected,with detection rates of 3.33％to 33.33％,all of which did not exceed the standard.Some samples showed mixed residues of multiple pesticides.Conclusion This method can effectively avoid interference caused by matrix effects of different samples,and its accuracy,precision,and sensitivity all meet the requirements of detection standards.It has the characteristics of simplicity,stability,reliability,and ease of operation,and is suitable for the detection of batch sam-ples.
QuEChERSIsotope-labeled internal standardsUPLC-MS/MSPlant based foodPesticide residues
NETL
NSTL
万方数据
