Study On Rapid Screening Of Pesticides And Antibiotics In Soil

As an essential cultivating additions, pesticides play an important role in modern agriculture.However, they also have an adverse impact. As the country with the largest consumption of pesticides in the world, there are misuse and overuse pesticides by ignorance or a lack of safety concerns. Similarly,antibiotics play an active role in livestock and poultry, aquaculture and human disease, but the abuse of antibiotics is also serious in China. Excessive pesticides and antibiotics pour into the environment,result to environment contamination, and security threat with human and biology.In this study, 72 pesticides and 10 antibiotics which are high-toxic, long residual period, common used were chose. Compared different results by optimizing instrument conditions, extraction and clean-up process, and determination real sample to establishment optimized pretreatment procedure and instrument conditions.1. In this study, ion transitions and time segments were optimized, instrument method of 58 pesticides using gas chromatography-tandem mass spectrometry(GC-MS/MS) was established; besides,ion transitions, mobile phase and elution gradient of ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) were optimized, instrument method of 14 pesticides and 10 antibiotics using UPLC-MS/MS was established.2.In this study, choice of different buffer of Qu EChERS, type and volume of the extract solvent,shaking time and a dispersive solid phase extraction(d-SPE) clean-up were optimized, and then extraction and clean-up procedure were established. Validation experiments were performed in spiked soil samples. The average recoveries at 5 μg·kg-1 and 50 μg·kg-1 spiking levels ranged from 63% to119% with relative standard deviation(RSD) below 20%. The method limits of quantification(LOQ)ranged from 0.1 μg·kg-1 to 2 μg·kg-1. The determination coefficient(r2) were higher than 0.9901 in the linearity range of 0.25-500 μg·L-1 for all the pesticides.3.The optimized method was compared with established methods reported on different papers, and compared with shaking and accelerated solvent extraction(ASE). It has a comparable or more sensitive method LOQ, rapid and simple. Besides, ASE was unsuitable to target compounds in this study.4. The optimized method was then applied to test real soil samples collected from Shandong,Liaoning and Jiangsu provinces use this modified method. It had a good agreement with traditional shaking method.