BACKGROUND: This study was conducted to select and validate the quick and simple analytical method for tolpyralate, a benzoylpyrazole herbicide, in five agricultural products using QuEChERS(quick, easy, cheap, effective, rugged and safe) method and LC-MS/MS(liquid chromatography-tandem mass spectrometry).
METHODS AND RESULTS: The QuEChERS method was extracted with acetonitrile followed by addition of anhydrous magnesium sulfate, sodium chloride, disodium hydrogencitrate sesquihydrate and trisodium citrate dihydrate. After shaking and centrifugation, purification was performed with d-SPE(dispersive-solid phase extraction) sorbents. To validate the optimized method, its selectivity, linearity, LOD(limit of detection), LOQ(limit of quantitation), accuracy, repeatability, and reproducibility from the inter-laboratory analyses were considered. LOQ of the analytical method was 0.01 mg/kg at five agricultural products and the linearity of matrix-matched calibration were good at seven concentration levels, from 0.0025 to 0.25 mg/L (R2≥0.9980). Mean recoveries at three spiking levels (n=5) were in the range of 85.2~112.4% with associated relative standard deviation values less than 6.2%, and the coefficient of variation between the two laboratories was also below 13%. All optimized results were validated according to the criteria ranges requested in the CODEX and MFDS guidelines.
CONCLUSION: Based on the results of this study, the selected and validated method could serve as a basic data for inspecting tolpyralate residue in imported and domestic agricultural products, and establishing the maximum residue limit.