介孔分子筛SBA-15分离富集-火焰原子吸收光谱法测定矿样中铅

Determination of lead in mineral samples by flame atomic absorption spectrometry after separation/preconcentration with mesoporous molecular sieve SBA-15

研究了介孔分子筛SBA-15材料对痕量Pb2＋的分离富集性能,探讨了溶液pH值、温度、洗脱条件及共存离子对铅分离富集的影响。在最佳实验条件下,介孔分子筛SBA-15能定量、快速吸附试液中的痕量Pb2＋,其静态饱和吸附容量为5.36 mg/g,吸附在介孔分子筛SBA-15上的Pb2＋可用0.05 mol/L HNO3-CH3COOH完全洗脱,洗脱下来的Pb2＋用火焰原子吸收法测定,方法线性范围为0.05~25.00μg/mL,铅的检出限为35 ng/mL。该方法已用于标准矿样和日常矿样中铅的测定,两个标准矿样测定结果的相对标准偏差（RSD）分别为3.8%和4.5%（n=5）,日常矿样的加标回收率在98.7%~106%之间。

The separation and enrichment properties of mesoporous molecular sieve SBA-15 to trace Pb2＋ were studied.The effect of solution pH,temperature,elution condition and coexisting ions on the separation and enrichment of Pb2＋ was discussed.Under the optimal experimental conditions,the mesoporous molecular sieve SBA-15 could quantitatively and rapidly adsorb Pb2＋ in sample solution.The static saturation adsorption capacity was 5.36 mg/g.The adsorbed Pb2＋ on mesoporous molecular sieve SBA-15 could be fully eluted with 0.05 mol/L HNO3-CH3COOH.The eluted Pb2＋ was determined by flame atomic absorption spectrometry.The linear range of method was 0.05-25.00 μg/mL.The detection limit of lead was 35 ng/mL.This method has been applied to the determination of lead in standard mineral and daily mineral samples.The relative standard deviations（RSD） were 3.8 % and 4.5 %（n=5）,respectively.The recoveries of standard addition were 98.7 %-106%.