电感耦合等离子体质谱法检测农作物土壤中的镉、锡、锰、锑、钒、钛、锶金属污染物残留

建立全自动石墨消解–电感耦合等离子体质谱(ICP–MS)法检测农作物土壤中的镉、锡、锰、锑、钒、钛、锶金属污染物残留的分析方法。随机采集农作物土壤,取约200 g,置于烘箱中烘干,烘干后的样品用粉碎机粉碎,精密称取粉碎后的样品约0.25 g,置于聚四氟乙烯材质的消解罐内,按既定消解程序进行自动消解处理,得样品溶液,上ICP–MS仪,内标法定量检测。镉、锡、锰、锑、钒、钛、锶的质量浓度在0.03~12 ng/mL范围内与其响应值具有良好的线性关系,线性相关系数r~2均大于0.998。检出限为0.03~12.0 ng/mL,3水平样品加标回收率为88.9%~104.3%;方法的精密度为2.56%~4.59%(n=7)。实验证明该方法具有简单、灵敏度高、重复性良好等特点,可以用于农作物土壤中极微量金属污染物残留的检测。

Determination of cadmium,tin,manganese,antimony,vanadium,titanium and strontium in crop soil by inductively coupled plasma mass spectrometry

An automatic graphitic digestion–inductively coupled plasma mass spectrometry(ICP–MS)method for determining residual amounts of cadmium,tin,manganese,stibium,vanadium,titanium and strontium in crop soil was established.Crop soil samples were collected randomly first,then samples was dried in the oven and crushed.0.25 g crushed samples was precisely weighed and took to automatic graphite digestion for digestion,according to digestion procedure.Samples was detected on ICP–MS,internal standard method was selected for quantitative analysis.Cadmium,tin,manganese,stibium,vanadium,titanium and strontium showed good linear relationships in the concentration range of 0.03–12.0 ng/mL,with the correlation coefficients(r2)all more than 0.998.Average recoveries in 3 different concentrations were in the range of 88.9%–104.3%.The detection limits were 0.003–0.006 ng/mL.Relative standard deviations of repeatability were 2.56%–4.59%(n=7).The method is simple pre-treated,high sensitivity and good repeatability,which can be used for the detection of trace metal contaminant residues in crop soil.