饮用水中痕量银的聚合物改性硅胶固相萃取-火焰原子吸收光谱法测定

研究了以聚异丁烯-alt-马来酸酐和L-半胱氨酸改性硅胶固相萃取-原子吸收光谱法(SPE-FAAS)测定饮用水中痕量银的方法;考察了样品pH、进样体积、流速,以及洗脱剂种类、浓度、体积、流速等参数对萃取率的影响,同时研究了共存离子的影响,评价了萃取材料的吸附容量及再生性能.结果表明,在优化的实验条件下,该法的检出限(3σ)为1.5μg.L-1,相对标准偏差(RSD)为2.9%(c=20μg.L-1,n=7),富集倍数为18.7.该法可成功地用于测定井水、自来水、纯净水等水样中的痕量银.

Determination of trace silver in drinking water by solid phase extraction of polymer-modified silica gel combined with flame atomic absorption spectrometry

A method was established based on solid phase extraction of silica gel modified with poly（iso-butylene-alt-maleic anhydride） and L-cysteine in association with flame atomic absorption spectrometry to determine trace silver in drinking water. The effects of pH value, volume, and flow rate of to-be-tested water samples, as well as the concentration, volume and flow rate of eluant on the extraction rate were investigated. In the meantime, the effect of coexisting ions was studied, and the adsorption capacity and reproductive performance of the modified silica gel were examined. Results indicate that, under the optimized conditions, the present method has a detection limit （3a） of 1.5 μg ·L-1 for silver, a relative standard deviation of 2.9% （c = 20 μg·L-1, n = 7） and an enrichment factor of 18.7, and it can be successfully adopted to determine trace silver in drinking water samples collected from well water, tap water and purified water.