Residue behavior of sodium 4-chlorophenxyacetate in litchi and soil

An effective method was developed for the determination of sodium 4-chlorophenxyacetate residue in litchi. Field trials were designed to evaluate the dissipation and residue of sodium 4-chlorophenxyacetate in litchi at two locations:Guangdong and Guangxi. Samples were extracted by solution of sodium hydroxide, and further distributed by ethyl acetate after adjusting pH value into 2.5 by HCl and detected by high performance liquid chromatography with photo-diode array. The results showed that average recoveries ranged from 81% to 85% with relative standard deviations of 1.9%-4.6% at the spiked level of 0.01, 0.1 and 1 mg/kg. The limit of detection was 0.005 mg/kg and the limit of quantification was 0.01 mg/kg. Half-lives of sodium 4-chlorophenxyacetate ranged from 3.2 to 5.9 days in litchi and from 15.2 to 20.6 days in soil, respectively. The terminal residues of sodium 4-chlorophenxyacetate in litchi were below 0.01 mg/kg.