Simultaneous Determination of Naled and Its Reduced Product Dichlorvos by Gas Chromatography

A method for simultaneous determination of Naled and its reduced product Dichlorvos (DDVP) in agricultural products by FPD-GC was developed. Pesticides were extracted with acetone, purified by a coagulating reagent containing ammonium chloride and phosphoric acid, re-extracted with ethyl acetate, and determined by FPD-GC. Content of Naled was calculated as the total of Naled and DDVP because a part of Naled is immediately converted to DDVP. Recoveries were 20.1-83.1% for Naled and 47.5-97.0% for DDVP in 8 agricultural products, apple, cabbage, Japanese radish, cucumber, pumpkin, tomato, brown rice, and green tea at the fortification level of 0.2 or 0.4ppm. Detection limits of Naled were 0.005ppm for vegetables and fruits, and 0.01ppm for brown rice and green tea, respectively. Detection limits of DDVP were 0.002ppm for vegetables and fruits, and 0.004ppm for brown rice and green tea, respectively. No Naled or DDVP was detected among 8 agricultural products tested here.