Analysis Of Multiple Pesticide Residues And Dynamic Degradation Research In Edible Fungi

It is serious that the pesticide residues exceeded maximum residue limit in Chinese edible fungi. This is not only serious harm to people’s health, but also seriously affect import and export trade in edible fungi. In order to rapid detection of pesticide residues in edible fungi and to ensure the environmental safety of edible fungi, a method was established by procymidone and triadimefon etc.25pesticides multi-residue analysis by gas chromatography (GC-ECD) detection in edible fungi and substrates, and research on the degradation dynamics of procymidone and triadimefon in edible fungi and substrates. The sample was extracted by acetonitrile, column chromatography purification by Florisil and using N-hexane+acetone (volume ratio of85:15) mixed eluent leaching. In the range of the added concentration, the average recovery of25pesticides was70%to113%, the coefficient of variation was1.2%to11.6%in edible fungi. The average recovery was71%to106%and the coefficient of variation was2.1%-10.5%in in edible fungi and substrates. The minimum detectable concentration of ostreatus was0.00048mg/kg-0.0037mg/kg. The minimum detectable concentration of citrinopileatus was0.00048mg/kg-0.0037mg/kg. The minimum detectable concentration of substrates was0.00035mg/kg-0.0035mg/kg.The method that low limits of detection, high sensitivity, good recovery and good linearity could better meet the requirements of25pesticides multi-residue analysis in ostreatus and citrinopileatus.A method was established by residues analysis the fungicide procymidone and triadimefon in edible fungi and determine residual dynamic of procymidone and triadimefon to edible fungi and substrates by GC-MS. The results show that the average recovery of procymidone and triadimefon were87.7%-103.0%and84.4%-95.9%, respectively. The coefficient of variation were1.4%-9.0%and3.1%-8.3%, respectively. The minimum detectable concentration of procymidone simple was0.006mg/kg and the minimum detectable concentration of triadimefon simple was0.004mg/kg. Degradation processes were in line with a kinetic equation. The half-life day of procymidone in edible fungi and substrates were3.5d-6.9d and15.3d, respectively and the half-life day of triadimefon in edible fungi and substrates were2.3d-3.1d and14.2d, respectively. The last residue of procymidone and triadimefon in edible fungi and substrates were less than0.001mg/kg.