Evaluation Of Common High Purity Solvents For Pesticide Residues Analysis And Its Purification Process

High-purity organic solvents are increasingly used in chromatographic analysis,spectroscopic analysis,pesticide residue detection,mass spectrometry,organic synthesis and combinatorial chemistry,DNA and RNA synthesis.As a representative of high-purity solvents for Pesticide residue analysis,Pesticide residue grade organic solvents have been widely used in food safety,environmental monitoring and clinical medicine.At present,the commonly used Pesticide residue grade organic solvents are:methanol,acetonitrile,n-hexane,isopropanol,ethyl acetate,dichloromethane and petroleum ether etc.Among them,Pesticide residue grade acetonitrile has become one of the most widely used solvents for pesticide residue detection because of its excellent extraction effect on most pesticides.At present,there are two main aspects of bottlenecks in the production of pesticide residues in China:1)Domestic reagents cannot completely remove trace impurities of10^-12g/g?ppt grade?in raw materials and it is easy to introduce new impurities.2)There is no uniform reliable pesticide residue evaluation standards and testing technology;for these two drawbacks,We research group has carried out the evaluation of the quality indicators of seven common domestic and foreign pesticide residue reagent,compared them and found the gap between the domestic pesticide residues and foreign pesticides.We have also developed the product standards that are more suitable for applications and a set of system-available purification processes that has been established to produce pesticides which are more suitable for pesticide residue analysis.The main work is as follows:?1?Developping the Evaluation of suitability with respect to common reagent for pesticide residue analysis such as methanol,acetonitrile,ethyl acetate,n-hexane,isopropanol,petroleum ether and dichloromethane.With emphasis on the purification process of acetonitrile.?1?We have researched the difference about the quality indicators of the seven types of pesticide residue reagent in six companies at home and abroad,and made a product standard more suitable for application based on the differences.?2?A comprehensive evaluation system for pesticide residue reagent was established.The impurities in pesticide residue reagent were qualitatively analyzed by UV spectrophotometer,gas chromatography and gas chromatography-mass spectrometry.?3?We have designed the purification process for unqualified pesticide residues reagent.An adsorption-filtration test combination process was established to prepare for the subsequent pilot scale amplification and a better pesticide residue grade reagent product suitable for pesticide residue analysis was prepared.The product was passed through Guangdong University of Technology,Anhui Fulltime Specialized Solvent&Reagent Co,Ltd and Dongguan entry and exit inspection and Quarantine Bureau.It was verified by these analytical laboratory.The quality of six domestic and foreign reagent brands was Compared.The results showed that:the quality of our product is stable and reliable compared with similar international products.?2?Developing series of the standard specification for pesticide residue grade and formulating the quality control indicators for domestic pesticide residue grade acetonitrile.?1?.Taking research of seven representative pesticide grade high purity reagent products from well-known domestic and foreign reagent companies.The indicators were compared,and the differences between it were studied and the key indicators were confirmed.?2?According to the different index,with reference to foreign brand standards and in combination with the actual situation in our country,the pesticide residue grade acetonitrile standard suitable for the development of China's national conditions was developed.?3?Comparing the chromatographic peaks of the purified product and the pesticide standard under the same conditions and other indicators,it was found that the purified solvent can completely replace the foreign similar products and has the advantage of competition with the international.