基于电沉积富集-LIBS的水中Cd元素高灵敏稳定测量研究

Highly sensitive and stable measurement of Cd in water based on electrodeposition enrichment-LIBS technology

针对水体痕量Cd元素的高灵敏稳定检测,基于Al片电沉积富集(ED)结合激光诱导击穿光谱(LIBS)检测的ED-LIBS水中Cd分析方法,实验研究了富集时间、富集电压、导电溶质KCl浓度以及电极表面砂纸打磨对Cd元素富集结果的影响。结果表明,经砂纸打磨Al片电沉积富集后,Cd元素富集稳定性得到提升,同时优化确定的富集电压、富集时间和KCl浓度分别为−2.4 V、1200 s和2 g/L。利用该方法,Cd元素检测限和相对标准偏差分别为0.0021 mg/L和3.30%,满足《生活饮用水卫生标准》指标检测需求,为水体中痕量Cd元素的高灵敏稳定分析提供了有力的检测手段。

Aiming at the highly sensitive and stable detection of trace amounts of Cd2+in water,an experimental study based on Al sheet electrodeposition enrichment(ED)combined with laser-induced breakdown spectroscopy(LIBS)to detect Cd in water analysis method(ED-LIBS)is carried out.The effects of enrichment time,enrichment voltage,concentration of conductive solute KCl,and sandpaper polishing on the electrode surface,on Cd element enrichment are analyzed.The result shows that the enrichment stability of Cd element is improved after the Al flakes for electrical-deposition being polished by sandpaper.The optimized enrichment voltage,enrichment time and concentration of KCl are−2.4 V,1200 s and 2 g/L,respectively.By using the proposed method,the detection limit and relative standard deviation of Cd element are 0.0021 mg/L and 3.30%,respectively,which meets the detection requirement of"Sanitary Standards for Drinking Water"and provides an optional method for the highly sensitive and stable analysis of trace Cd elements in water.