Determination of Metalaxyl Residues in Watermelon and Banana by HPLC.

A determination method for metalaxyl(MEL) residues in watermelon and banana had been established by automated solid-phase extraction(SPE) coupled with high performance liquid hromatography(HPLC). Samples were extracted by acetonitrile, homogenized, filtrated, extracted by automated solid-phase extraction(SPE), and finally purified by C18 column. The experiment was carried on SunFireTM C18 column with the mobile phase of acetonitrile-water-methanol(25:40:35, by vol) at the flow rate of 1.0 mL/min. The detection wavelength and injection volume were set at 220 nm and 10 uL, respectively. The recoveries of three different concentrations(0.02, 0.20, 1.00 mg/kg) for watermelon and banana were 94.3%-101.0% and 81.5%-99.6%, respectively. RSD(n = 5)were 1.30%-5.29% and 2.66%-6.67%, respectively. The lower detection limit for metalaxyl was 0.006 mg/kg. This method met with the requirements of pesticide residue detection. [ABSTRACT FROM AUTHOR]