液相-原子荧光联用技术(LC-AFS)对紫菜中无机砷的测定

Determination of Inorganic Arsenic in Laver by Liquid Chromatography Atomic Fluorescence Spectrometry

无机砷是紫菜质量检验中主要的安全卫生指标。通过对紫菜样品的线性范围、检出限、回收率、精密度的测量,建立了液相-原子荧光联用技术(LC-AFS)测定紫菜中无机砷含量的方法。实验结果表明,用1.2 mol/L HCI在70℃水浴下提取2.5 h,用双氧水氧化,以磷酸二氢铵溶液为流动相进行LC-AFS分析,样品加标量在15 ng/mL、50 ng/mL和80 ng/mL时的平均回收率为88.0%~104.4%,相对标准偏差1.9%,方法精密度较高。该方法检测准确、可靠,具有良好的精密度,适用于紫菜中无机砷的检测。

Arsenic is an important safety index of laver in quality inspection. The determination method of inorganic arsenic in laver by using the liquid chromatography atomic fluorescence spectrometry （LC-AFS） is developed, when the linearity, detection limit, recovery rate and precision of the sample were measured. The research results show that, With 1.2 mol/L HCI in 70 ℃ water bath extraction under 2.5 h （H2O2） with hydrogen peroxide oxidation, with two hydrogen ammonium phosphate solution as mobile phase was analyzed by LC-AFS, the average recovery of samples with 15 ng/mL, 50 ng/mL and 80 ng/mL in the scalar at the rate of 88 %-104.4 %, the relative standard deviation of 1.9 %. The method has high detection accuracy, good precision, and is suitable for the determination of inorganic arsenic in laver.