Dissipation and residue behavior of oxine-copper on litchi field application

An analytical method was established for oxine-copper residues in litchi, litchi pulp and soil. The residue levels and dissipation rates of oxine-copper was detected by high performance liquid chromatography- photodiode array (HPLC-PDA). At three fortification levels of 0.10, 0.50 and 2.00 mg/kg in litchi, litchi pulp and soil, recoveries were in the range 80.1 to 103.5%, with relative standard deviations (RSD) of 1.52 to 12.07%. The limit of quantification (LOQ) of method was 0.01 mg/kg for litchi, litchi pulp and soil. The half-lives of oxine-copper in litchi and soil were 9.12 and 7.02 day, respectively. The final residue levels of oxine-copper in litchi, litchi pulp and soil were lower than 1.99 mg/kg at harvest.   Key words: Oxine-copper, pesticide residue, dissipation, litchi, soil.