溶剂吸收-气相色谱-质谱法测定地表水中二硫代氨基甲酸酯类农药

Determination on dithiocarbamates pesticideresidues in surface water by gas chromatography-mass spectrometry with solvent absorption

目的采用溶剂吸收-气相色谱-质谱法测定地表水中二硫代氨基甲酸酯类农药,为检测地表水污染情况提供有效的检测方法。方法水体样品中二硫代氨基甲酸酯类农药(包括福美双、福美锌、代森锰锌等)在加热的密闭顶空瓶中,与SnCl_(2)-HCl发生反应生成CS_(2),待降温后,用正己烷萃取CS_(2),通过气相色谱-质谱法测定正己烷相中CS_(2)的量,以此检测二硫代氨基甲酸酯农药的残留量。结果CS_(2)在0.02~0.50μg/ml的线性范围内线性关系良好(R^(2)=0.99929),CS_(2)在0.50~10μg/ml的线性范围内线性关系良好(R^(2)=0.99979);检出限为0.003 mg/kg,定量限为0.01 mg/kg,回收率为90%~110%,其相对标准偏差为2.73%~5.03%。结论该方法简单快捷、灵敏度高、精密度高、回收率好,用于实际样品的检测结果令人满意。

Objective Gas chromatography-mass spectrometry with solvent absorption was used to determine dithiocarbamate pesticides residues in surface water,so as to provide an effective method for detecting surface water pollution.Methods The dithiocarbamate pesticides residues(including TMTD,ziram,mancozeb,etc.)in water samples reacted with SnCl2-HCl in a heated closed headspace bottle to generate CS_(2).After cooling,the liberated CS_(2) was absorbed by hexane and then determined by gas chromatography-mass spectrometry,so as to detect the residual amount of dithiocarbamate pesticides residues.Results Carbon disulfide has a good linear relationship in the linear range of 0.02-0.5 ug/ml(R^(2)=0.99929)and 0.5-10 ug/ml(R^(2)=0.99979).The limits of detection were 0.003 mg/kg and the limits of quantitation were 0.01 mg/kg.The average spiked recoveries were in the range of 90%-110%.The relative standard deviation was from 2.73%to 5.03%.Conclusion The method is simple,rapid,sensitive,accurate and has good recovery rate.It is suitable for the detection of dithiocarbamate pesticides residuesin surface water.