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通过扫描电镜(SEM)、静态氮吸附(NSA)和红外光谱(FTIR)法对塔卡拉玛干沙漠自然沙粒(简称沙粒)的粒状及其表面结构、比表面积和功能基团进行了分析,以FAAS作为检测手段,动态法研究了沙粒对Pb2+的吸附性及其影响因素并优化了吸附条件;将沙粒作为填料制备了5.0cm×5mm i.d.预富集分离微柱,将其与FAAS联用,提出了沙粒预富集分离微柱-FAAS法测定痕量Pb2+的方法;结果表明:沙粒具有不规则的颗粒形状、粗糙的多孔(坑)表面形貌和硅羟基基团;其粒径分布主要在100～154μm之间,比表面积为7.60m2.g-1,平均孔(坑)径为3.91nm,在室温下pH为6的铅溶液以2.55mL.min-1的流速通过分离柱时对Pb2+的动态吸附量可达到24.9mg.g-1,吸附率为91.5%,选用0.1mol.L-1的盐酸溶液进行解吸,解吸率为99%。
The granularity, surface structure, specific surface area and functional groups of the natural sand in the Takalimakan Desert (sand) were analyzed by scanning electron microscopy (SEM), static nitrogen adsorption (NSA) and infrared spectroscopy (FTIR) , FAAS was used as the detection method to study the adsorption of Pb2 + on sand by dynamic method and its influencing factors, and the adsorption conditions were optimized. The 5.0cm × 5mm id preconcentration column was prepared using sand as filler, FAAS combined with sand column pre-enrichment separation micro-column-FAAS method for the determination of trace Pb2 +; results show that: sand with irregular particle shape, rough porous (pit) surface morphology and silanol groups ; Its particle size distribution mainly between 100 ~ 154μm, the specific surface area of 7.60m2.g-1, the average pore diameter of 3.91nm, at room temperature pH 6 lead solution 2.55mL.min-1 The dynamic adsorption capacity of Pb2 + can reach 24.9mg.g-1 when the flow rate passes through the separation column, the adsorption rate is 91.5%, and the desorption rate is 99% with 0.1mol.L-1 hydrochloric acid solution.