蔬菜水果中无机砷测定方法改进研究

研究改进了应用原子荧光法测定蔬菜水果中无机砷的前处理方法,用6 mol/L盐酸在70℃水浴中提取1 h,使试样充分浸提。吸取4 mL浸提液于10 mL容量瓶或具塞刻度试管中,加碘化钾-硫脲混合液1 mL,消泡剂(正辛醇)3~5滴,加水定容后测定试样中的无机砷。方法检出限为干样0.02 mg/kg,鲜样0.01 mg/kg,完全能够满足国家卫生标准限量和农产品认证指标测定的要求。

Research on Modified Pre - processing Method of Determination of Inorganic Arsenic in Vegetables and Fruit

A modified pre-processing method of determination of inorganic arsenic in vegetables and fruit use of atomic fluorescent spectum is reported.The samples were extraceted with 6 mol/L HCl solution for 1 h in water bath,then,imbibe 4 mL extract liquor in 10 mL measuring flask or 10 mL graduated test tube,and 1 mL miscible liquids of potassium iodide and thiourea and 3 to 5 drop of n-octanol.After constant volume,use atomic fluorescent spectrum to determination the inorganic arsenic.The detection limit of dry samples and fresh samples is 0.02 mg/kg and 0.01 mg/kg respectively,which absolutely meet the demand of determination of inorganic arsenic in vegetables and fruit according to national hygienic standards and agro-product certification factors.