抄録
A method is described for the determination of acephate in water sample. The water sample was evaporated to dryness. After addition of unhydrous sodium sulfate, acephate was extracted with dichloromethane from the residue. The dichloromethane extract was concentrated in a Kuderna-Danish apparatus to 3-5ml and continue evaporation to 0.5ml under a nitrogen stream. Acenaphthene-d10 (0.5m1 of 1.0ppm dichloromethane solution) as internal standard and acetic acid (50μl) were added and determined by capillary gas chromatography-selected-ion monitoring (GCSIM) . As the addition of acetic acid was effective to prevent adsorption of acephate to injection port, high respons and low relative standard deviation were obtained. In addition, as acephate was very sensitive to column condition, the peak extremely tailed under inferior column condition. The recoveries and relative standard deviation in parenthesis for distilled water and river water were 91.8% (3.2%) and 96.4% (5.0%), respectively. However, acephate was not recovered from tap water, since it was decomposed by residual chlorine. In this method, the detection limit of acephate was 0.5ng.
