Simultaneous determination of chlorothalonil and its metabolite in fruits and vegetables using modified QuEChERS-high performance liquid chromatography-tandem mass spectrometry

An analytical method for simultaneous determination of chlorothalonil and its metabolite chlorothalonil-4-hydroxy in fruits and vegetables was developed using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The samples were extracted by acidified acetonitrile, and the extraction solution was analyzed by HPLC-MS/MS equipped with APCI ion source. The results showed that good linearity was obtained in the range of 0.005-0.2 mg/L with correlation coefficients (R²) greater than 0.99. The limits of quantification were 0.01 mg/kg. At the spiked levels of 0.01, 0.05, and 0.2 mg/kg, the average recoveries in four sample matrices (cabbage, cucumber, grape, and apple) were 83%-104% with the relative standard deviations (RSDs) varying from 0.73% to 7.7% (n=6). The proposed method is simple, rapid, accurate and reliable, and it is suitable for the quantitative determination of chlorothalonil and its metabolite in fruits and vegetables.