气相色谱法测定马铃薯中代森锰锌残留量

Detection of Mancozeb Residue in Potato by Capillary Gas Chromatograph

为了建立马铃薯中代森锰锌农药残留检测的气相色谱分析方法,在100mL顶空瓶中,样品中的代森锰锌与氯化亚锡酸性溶液在80℃下反应2 h后产生二硫化碳(CS_2),CS_2经正己烷收集后采用CP-SILSCB毛细管柱(30 m×0.32 mm×3μm)分离,电子捕获检测器(ECD)测定,以CS_2含量表示代森锰锌残留量。代森锰锌反应生成的CS_2在0.05~1.00 mg/kg范围内峰面积和浓度成良好的线性关系(R^2=0.9979),回收率为91.7%~102.0%,相对标准偏差为2.7%~4.6%,检出限为0.01 mg/kg。该方法简便、准确可靠,适用于马铃薯中代森锰锌残留量的测定。

A method based on capillary gas chromatography （GC） was developed to detect mancozeb residue in potato. In a headspace vial of 100 mL, mancozeb in samples was reacted with acid stannous chloride to produce carbon disulfide （ CS2 ） by heating at 80 ℃ for 2 hours. CS2 was separated on a capillary column （ CP-SIL5 CB ,30m×0.32mm×3μm） after collected by n-hexane, and then, it was detected by GC-ECD. Results showed that the calibration curve for CS2 produced by mancozeb had a good linearity in the range of 0.05 mg/kg to 1.0 mg/kg and the linear correlation coefficient was 0. 9979. The recoveries of mancozeb in potato ranged from 91.7 % to 102.0 %, the relative standard deviations ranged from 2.7 % to 4.6 %, and the detection limit （3S/N） of this method was 0.01 mg/kg. The method is simple, accurate and reliable. It is suitable for the detection of mancozeb residues in potato.