Study On Rapid Detection Of Dithiocarbamate And Pyrethroid Pesticide Residues In Agricultural Products

This paper reviewed the application and development of rapid detection of pesticide residues. The detection method of dithiocarbamate and pyrethroid pesticides residues in agricultural products was summarized in emphasis. On this basis, a new rapid detection technology was explored. The rapid detection method of dithiocarbamate pesticides residues in agricultural products was established and the rapid detection of pyrethroid residues was preliminary studied. In addition, the detection tube method is developed and used in the rapid detection of dithiocarbamate to do some exploratory research.In the rapid detection technology of pesticide residues, enzyme inhibition method is the most widely used and relatively mature method. The method is fast, broad-spectrum and low-cost and is mainly used in organic phosphorus and carbamate pesticides. In the detection of dithiocarbamate and pyrethroid pesticide residues, chromatography method is chiefly adopted. However, the chromatography method requires expensive instruments and completed sample pre-treatment process, meanwile it is times consumptive and high-cost, which is not suitable for rapid screening test. Therefore, the study on rapid detection of dithiocarbamate and pyrethroid pesticide residues in agricultural products are of great significance.The results are as follows:1. A kind of rapid detection method was explored based on the development of rapid detection devices. The principle of this method was: in the rapid detection devices, the measured materials were decomposed into a kind of volatile component through chemical reactions. The volatile component was passed by the foreign aid gas (eg. nitrogen) from the matrix of the elements to the absorbing devices and was detected after the high sensitivity color reaction in the color liquid.2. The rapid detection method of dithiocarbamate pesticides residues in agricultural products was established. Dithiocarbamate pesticides in the sample were decomposed to carbon disulfide. Then carbon disulfide was carried by nitrogen to the absorption color solution. It was detected by UV spectrometer. The recoveries were 83～117% and the coefficients of variation from 4.0% to 7.7%. The detection limit was 0.15μg/g. This method was a simple and low-cost method for detecting dithiocarbamate residues in agricultural products. Colorimetric card was developped basing on the spectrophotometry method which made the detection faster and easier.3. The carbon disulfide test tube was developed by the experiment of the test tube materials,reagent selection and color conditions test. And it could be used for dithiocarbamate pesticide residues. After the sample was treated by rapid detection device, we could quickly determine whether the sample contains dithiocarbamate pesticides residues by the color change of the test tube.4. The rapid detection method of containing cyanogen of pyrethroid pesticides residues in agricultural products such as tea was established. In the rapid detection devices, containing cyanogen of pyrethroid pesticides in the sample were decomposed to volatile compound by alkali. Then the volatile compound was carried by nitrogen to the absorption color solution. It was detected by colorimetric assay. The detection limit was 0.4μg/g, the RSD was not more than 6% and the recovery rate was 75.0%～128.0%. The method could be used for the rapid detection of these pyrethroid pesticides residues in tea.The rapid detection method of dithiocarbamate and containing cyanogen of pyrethroid pesticides residues in agricultural products was established. This features of this method were simple, rapid,low-cost and broad spectrum. It improved the rapid detection technology of pesticide residues in agricultural products and was of great significance on the protection of the agricultural products safety.