Abstract: The effects of washing solutions on the elimination of residues of metalaxyl and difenoconazole in pakchoi cabbage were determined by GCMS/MS. The results indicated that solutions including tap water， NaCl， NaHCO3， acetic acid and detergent solution played different roles in the reduction of pesticide residues. The removal efficiency decreased in the order of detergent solution > NaCl solution > NaHCO3 solution > tap water > acetic acid. The removal efficiency of the 2 pesticides increased with the increasing concentration of NaCl in solution. In general， the removal efficiency of difenoconazole was higher in all the washing solutions than that of metalaxyl， which indicated that the removal efficiency of these 2 pesticides was not correlated with their water solubility．

Key words: metalaxyl, difenoconazole, pesticide residues