Residual Analysis of Profenofos in Cotton and Soil

The residue dynamics and final residual levels of profenofos in cotton and soil are determined with GC-ECD.A method for pretreatment and analysis of samples is established.The results indicate that when spraying 500 g·L-1 profenofos emulsion to cotton,the primitive quantities of sediment in cotton leaves are 110 mg·kg-1 in Ji'nan and 83 mg·kg-1 in Changsha trial site,and the half-life of both are 0.7 d and 1.4 d,respectively.The primitive quantities of sediment in soil are 4.8 mg·kg-1 in Ji'nan and 7.2 mg·kg-1 in Changsha trial site,and the half-life of both are 0.5 d and 2.2 d,respectively.The max final residues in cotton seeds is 0.049 mg·kg-1 in Ji'nan and 0.13 mg·kg-1 in Changsha trial site,which are all lower than the recommended MRLs of 2 mg·kg-1 by Codex.