Determination Of Benzoylureas And Bishydrazide In Vegetables By Ultra Performance Liquid Chromatography–tandem Mass Spectrometry With Matrix Solid Phase Dispersion

Vegetable industry, an advantageous and mainstay industry in Chinese export, has the potential of appreciation and add close. In order to guarantee the quality of vegetables and increase the output, many pesticides were applied to control of diseases and pests. However, pesticide residue caused serious pollution and serious people's health risk. In recent years, governments increased the number of test items of the vegetables for import and export constantly, and made more strict standards and lower MRL continuously, so exports of vegetables for our country were facing more and more technical barriers. Vegetable was also one of agricultural products which were most at risk of green trade barriers. Therefore, the analysis on the pesticide multi-residue of vegetables should be accuracy, efficient and rapid. Benzoylureas and bishydrazide were widely applied to vegetables and fruits. This research studied extraction, purification and UPLC-MS/MS detection conditions of the target benzoylureas and bishydrazide in vegetables (Chinese cabbages, Ball cabbages, Tomatoes, Broccolis, Perilla leaves), and developed an ideal analytical procedure based on MSPD coupled to UPLC-MS/MS for the determination of the two kinds of pesticides in vegetables. The main results were as follows:1. In this research, we optimized the kind of dispersant, eluent, and chose the suitable rate between sample and dispersant, the dosage of eluent and purificant. Then a preparation method which used alumina as dispersant (the best ratio between neutral alumina and sample was 2:1), graphitizand carbon black as purificant, and ethyl acetate as eluting solvent (1.0g sample used 30 mL and ethyl acetate as eluting solvent ) was established. The recoveries were 78.5-112.8% at four spiked levels of 1, 5, 10 and 100μg/kg, and the relative standard deviations was 2.3%-10.2%.2. In this research, we optimized the MS/MS condition, chose the suitable mobile phase and mobile phase program, and then a UPLC-MS/MS detection method for the target benzoylureas and bishydrazide was established successfully. The separation was achieved by ultra performance liquid chromatography, and the identification and quantification were performed using MS/MS with multiple–reaction monitoring (MRM) and electrospray ionization in positive or negative mode. The calibration curves showed good linearity in the range of 1-100μg/L with correlation larger than 0.99. The limits of determination (S/N=3) for the pesticides were 0.487-0.988μg/kg, which were lower than MRLs of our country and Japan's'Positive List System'.The proposed method was easier and faster to perform, and lower limits of quantification, and consumed less sample and organic solvents. It could meet the demands of practical use for the rapid and simultaneous determination of benzoylureas and bishydrazide in vegetables.