气相色谱法测定小麦粉中福美锌、福美双残留量

Determination of Thiram and Thiram Residues in Wheat Flour by Gas Chromatography

该试验旨在建立溶剂吸收-气相色谱法测定小麦粉中二硫代氨基甲酸酯/盐类残留总量方法,并分析方法的回收率、定量限和精密度。样品中二硫代氨基甲酸酯/盐类与3%氯化亚锡盐酸溶液在90℃水浴条件下反应生成二硫化碳,采用正己烷收集二硫化碳气体,经气相色谱ECD检测器分析,外标法定量,根据回收率、定量限和精密度考察方法的可行性。结果显示,该方法在二硫化碳0.5~50.0μg/mL质量浓度范围内的线性关系较好,在二硫代氨基甲酸酯/盐在0.79~4.0 mg/kg添加水平下的回收率为78.4%~90.6%,相对标准偏差为1.0%~2.94%(n=6),方法检出限为0.5 mg/kg (以CS2计)。试验建立了溶剂吸收-气相色谱法测定小麦粉中的福美锌、福美双残留量的测定方法,该方法快速、准确、灵敏,适合小麦粉中二硫代氨基甲酸酯/盐药物残留的测定。

The study was in order to establish a solvent absorption-gas chromatography method to determine the total amount of dithiocarbamate/salt residues in wheat flour, and the recovery rate, quantification limit and precision of the analytical method. The dithiocarbamates/salts was in the sample react with 3% stannous chloride hydrochloric acid solution at 90 ℃ in a water bath to generate carbon disulfide. The carbon disulfide gas was collected by n-hexane, analyzed by a gas chromatography ECD detector, and quantified by an external standard method. The feasibility of the method was investigated from the recovery rate, quantification limit and precision. The results showed that this method had a good linear relationship in the concentration range of carbon disulfide concentration of 0.5-50.0 μg/mL, and the recovery rate of dithiocarbamate/salt at 0.79-4.0 mg/kg addition level was 78.4%-90.6%. The relative standard deviation was 1.0%-2.94%(n=6), and the detection limit of the method was 0.5 mg/kg(calculated by CS2). This study established a solvent absorption-gas chromatography method for the determination of thiram and thiram residues in wheat flour. This method was fast, accurate, and sensitive, and it was suitable for the determination of dithiocarbamate/salt pesticide residues in wheat flour.