悬浮液进样-火焰原子吸收光谱法测定云冈石窟降尘中的锰

Direct determination of manganese in dust of Yungang Grottoes by flame atomic absorption spectrometry using suspension sample introduction

把降尘样品干燥磨碎并过200目筛后悬浮于0.15%琼脂胶体中制成悬浮液,用火焰原子吸收光谱法成功测定了云冈石窟降尘中锰元素的含量。对悬浮剂进行了选择,考察了共存离子的影响。在优化条件下测定锰的线性回归方程为A=2.9366c(μg/mL)-0.0075(r=0.9982),精密度为3.56%,检出限为0.0012μg/mL,回收率在101.9%～103.5%之间,方法简便、快速、无污染、无被测元素损失。

The dust sample powder passed through 75 μm of screen size was suspended in agar solution to prepare a suspension solution,and then the micro amount of magnesium in the suspension solution was determined by flame atomic absorption spectrometry.Selection of suspension and the influence of coexisting elements were studied.Under optimal conditions,the absorbance and manganese content was described by the equation：A=2.936 6c（μg/mL）-0.007 5（r=0.998 2）.The detection limit of this method for Mn was 0.001 2 μg/mL,relative standard deviation was 3.56% for samples（n=6）,and the recoveries for the method were in the range of 101.9%～103.5%.The method had the advantage of simple and rapid operation,reduced environmental contamination,and less loss of tested elements in the sample.