大米中总砷及无机砷含量分析

目的了解大米中砷的含量及分布。方法应用氢化物发生—原子荧光分析技术测定大米中总砷、无机砷,采用高压焖罐对大米样品进行消解测定总砷,用6mol/LHCl提取大米中无机砷,在3mol/LHCl条件下测定总无机砷。结果仪器检出限:总砷0.08ng/ml,无机砷0.10ng/ml;样品回收率:总砷90.5%～103.7%,无机砷为91.6%～105.5%;相对标准偏差:总砷4.1%～6.5%,无机砷4.2%～6.8%。所测大米中总砷含量范围为0.06～0.18mg/kg,无机砷含量范围为0.035～0.13mg/kg,无机砷占总砷的含量为42.5%～88.0%。结论在所检样品中,均检出无机砷与总砷,含量均在国家限量卫生标准以内。

Determination of the Total Arsenic and Inorganic Arsenic in Rice

Objective] To learn the concentration and distribution of arsenic in rice. Methods] Hydride Generation -Atomic Fluorescence Spectrometry was adopted to determine the total arsenic and inorganic arsenic in rice; high pressure jar was used for the dissolve to determine total arsenic in rice; 3 mol/L HCI was used to extract inorganic arsenic in rice; the total arsenic was determined under the condition of 3 mol/L HCI. Results ] The detection limits of total arsenic and inorganic arsenic were 0.08 ng/ml and 0.10 ng/ml respectively; the recovery rates of total arsenic and inorganic arsenic were 90.5% - 103.7% and 91.6% - 105.5% respectively; the RSD of them were 4.1% - 6.5 % and 4.2% - 6.8% respectively ; the total arsenic concentration in rice was 0.06 -0. 18 mg/kgand the inorganic arsenic was 0. 035 - 0. 13 mg/kg; the ratio of inorganic arsenic and total arsenic was 42.5% -88.0%. Conclusion] The total arsenic and the inorganic arsenic can be detected in all samples, but the content of them were below the tolerance limits.