Study On Residual Analysis And Digestion Of 20% Dichlorobenzazole Suspension On Potato

In current thesis, an analytical method of ultra performance liquid chromatography with PDA detector(UPLC-PDA) was established for the residue of ―erlvejunzuo‖ after extracting from soil, potato and potato foliage samples. The residue and degradation of ―erlvejunzuo‖ in potato were studied for the safe use of ―erlvejunzuo‖ and provide basic data for relevant standards.Soil sample was extracted with dichloride/n-hexane(1/1, v/v); potato and potato foliage sample were extracted with 20 mL 5% glacial acetic acid in acetonitrile and without further purification. The extracts were detected using UPLC-PDA on an ACQUITY UPLC® BEH C18 column. The calibration curve of ―erlvejunzuo‖ showed good linearity from 0.1–10 mg/L and 10–500 mg/L with the correlation coefficient were 0.9999 and 0.9998, respectively. The average recoveries of ―erlvejunzuo‖ were 83.45-99.88% for soil, potato and potato foliage when the fortified concentration levels were 0.01–10.0 mg/kg with the relative standard de viations were 1.90–8.22%. The accuracy and sensitivity of the method meet the requirements of pesticide residues analysis.Field residue trials of 20% erlvejunzuo(SC) on potato were carried out in Guizhou and Anhui province during 2013 and 2014(spraying for one time and two times and interval of 7 days at the low dosage and high dosage(375.0–562.5 g a.i/ha)). The results showed that the residues of ―erlvejunzuo‖ in the soil and potato in Guizhou and Anhui were not detected(under determination limit) at harvest time after spraying for the one and two dosage levels in 2013 and 2014. ―Erlvejunzuo‖ was rapidly degraded, it may be due to easily degradable or instability about this pesticide itself, in addition, volatilization of pesticides sprayed on plants in the field can be an important pathway of emission to the environment. The half- life of ―erlvejunzuo‖ variy from 4.3 to 6.8 days in potato foliage in Anhui 2013 and 2014; The terminal residues of erlvejunzuo on soil and potato was less than 0.01 mg/kg. Therefore, the proper application period, highest dosage and safe pre- harvest interval are after engraftment, 562.5 g a.i/ha(two times) and 7 d.The result of ―erlvejunzuo’s‖ degradation in different soils showed that the higher humidity, temperature and p H in soil, the faster speed of ―erlvejunzuo‖ degrade in the soil. The microorganism can promote the degration of ―erlvejunzuo‖, but organic matter can promote the stable of ―erlvejunzuo‖. In a word, the speed of ―erlvejunzuo’s‖ degradation in soil is mainly influenced by p H.