二硫代乙二酰胺改性硅胶固相萃取-火焰原子吸收光谱法测定水中的痕量铜和铅
Determination of Trace Copper and Lead in Water by FAAS Combined with SPE Using Dithiooxamide Modified Silica
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摘要: 制备了二硫代乙二酰胺改性硅胶作为固相萃取吸附剂,在pH 5.2,吸附时间为40 min时,得到Cu2+、Pb2+的最大静态吸附容量,分别为19.50,29.39 mg·g-1。水样中痕量的Cu2+、Pb2+经固相萃取后采用火焰原子吸收光谱法测定。在最佳条件下,Cu2+、Pb2+的线性范围分别为1.0~100,10~300 μg·L-1,检出限(3S/N)分别为0.7,5.0 μg·L-1。加标回收率在97.6%~104%之间。方法用于分析标准模拟水样,测定值与认定值相符。Abstract: Dithiooxamide modified silica gel was prepared and used as a absorbent in SPE. Under the conditions of pH 5.2 and the adsorption time of 40 min, the maximum static adsorption capacities of Cu2+ and Pb2+ obtained were 19.50, 29.39 mg·g-1, respectively. After being seperated and enriched by SPE, trace Cu2+ and Pb2+ in water were determined by AAS. Under optimum conditions, the linearity ranges of Cu2+ and Pb2+ were 1.0-100 μg·L-1 and 10-300 μg·L-1, respectively, with detection limits (3S/N) of 0.7 μg·L-1 and 5.0 μg·L-1, respectively. Recovery rates obtained by standard addition method were in the range of 97.6%-104%. The proposed method was applied to the analysis of standard reference material, giving results consistent with the certified values.