| The use of pesticides in agricultural production had made an indelible contribution to increaseagricultural production, but it also had a serious harm to the ecological environment and human healthbecause of the unreasonable use of high toxicity, high residue and difficult degradation pesticides.Research of detection technology for pesticide residues in soil will help people more deeply understandits dynamics and pollution mechanism, so as to playing the positive role of pesticide in agriculturalproduction. It was also beneficial us to adopt scientific means to eliminate or weaken the hazards forsoil, even the agricultural ecosystems and human health. The use of pesticide is very large in ourcountry. There was a very important theoretical and practical significance to establish accurate andreliable, high sensitivity and in line with international standards for the detection of pesticide residues,which could help us improve the detection ability of pesticide residues in agricultural environment fromoverall. It also could guarantee the quality and safety of agricultural products and avoid internationaltrade disputes. In this paper, we had selected65pesticides (organophosphorus, organochlorine,pyrethroid and carbamate, triazine herbicides), which were riskiest pesticide，used largely and had along residual period in soil. And the analytical methods of these pesticides had been studied. Thesamples were extracted with acetonitrile using mechanical shaking extraction (MSE) or acceleratedsolvent extraction (ASE), enriched and then cleaned up with solid-phase extraction（SPE）cartridge.Finally, the pesticides were determined by GC, HPLC, GC-MS/MS and UPLC-MS/MS. A set ofanalysis method had been established for the quantitative determination and confirmation of65pesticide residues in soil. The main research results are as follow:1. Compared with the different solvents on the extraction effect of pesticides using MSE and ASEin the paper, and the different extraction temperature for ASE had been compared too. The result ofMSE showed that acetone was volatile and emulsifying in the experiment. The extraction efficiency ofacetonitrile and dichloromethane were good, but dichloromethane had more harm to the environmentand human health. So acetonitrile was finally chosen as the extraction solvent. The result of ASEindicated that various pesticides had better recovery rate using acetonitrile as solvent extraction.Compared with acetonitrile extraction effect under different temperature, ultimately selected theacetonitrile as extraction solvent and60℃as extraction temperature.2. The soil extract was cleaned up by SPE. The type of co-extractives had been analyzed, whichbased on the result of GC-MS/MS detection. Compared with the effect before and after purification inthe experiment, it showed that the SPE cartridge could effectively remove the interfering substance inthe soil and thus reduced the pollution of the instrument.3. Instrumental analysis methods of65kinds of pesticide residues in the soil had been established.The linear regression analysis data indicated that the limits of detection and the linear relationshipbetween response and concentration were good. The method was also validated by analyzing spiked soilsamples. The result showed that the recovery of most pesticides ranged from70%to120%, and therelative standard deviations (RSD) less than20%. This method had good accuracy, precision, and could meet the actual requirements for the simultaneous determination of pesticide residues in soil.4. Compared with actual soil spiked recoveries of three regions with different pH and organicmatter content, we found that this method could get good recoveries of all soils. So it proved the methodhad strong practical application value. |
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