溶液阴极辉光放电技术作为一种新型的光谱检测技术, 被广泛应用于环境污染物的分析和检测等方面。 虽然该技术具有结构简单以及成本低等优势, 但是在重金属检测方面, 其灵敏度还有待提高。 针对上述问题, 搭建了氢化物发生-溶液阴极辉光放电光谱测量系统, 实现了对水体中痕量汞(Hg)和锡(Sn)的简单高效检测。 为了得到更优的检测效果, 实验选取270.64和253.65 nm作为Sn和Hg的特征分析谱线, 并将激发源的参数配置为极间距3.5 mm、 放电电流60 mA和电解液流速2.12 mL·min^-1。 同时, 实验对影响氢化物反应的相关实验条件进行了研究, 得到Sn和Hg的最佳硼氢化钠浓度为2%和1.5%, 载气流速为141.50和183.95 mL·min^-1, 样品溶液pH值为1.0。 随后为了进一步分析水体中共存离子对该系统检测性能的影响, 实验评估了Pb²⁺, Ca²⁺, Zn²⁺, Cr³⁺, Cd²⁺, Na⁺, K⁺, Mn²⁺, Mg²⁺, Fe³⁺和Cu²⁺对氢化物发生-溶液阴极辉光放电技术检测Sn和Hg的干扰情况, 结果表明仅Cu²⁺对两种元素的检测干扰较大, Pb²⁺对Hg的检测存在一定干扰, 其他共存金属离子未表现出明显的干扰情况。 基于上述实验条件的优化, 在最佳实验参数下利用外标法建立Sn和Hg的定标模型, 并计算得到Sn和Hg的检出限分别为6.85和1.05 μg·L^-1, 溶液信号强度的相对标准偏差均小于3%( n=10)。 最后, 实验中分别采集了三种不同水质的实际水样, 应用所提出的方法对Sn和Hg进行加标回收率研究, 用标准加入法测得其加标回收率均在97.77%~103.08%之间。 上述结果表明氢化物发生-溶液阴极辉光放电技术在Sn和Hg的检测方面表现出了良好的分析性能, 且该方法具有体积小、 成本低、 抗干扰能力强等优势, 有望为水体中重金属的元素检测提供一种更加简便高效的方法。

As a new type of spectroscopic detection technology, Solution Cathode Glow Discharge technology is widely used to analyse and detect environmental pollutants. Although this technology has the advantages of simple structure and low cost, its sensitivity needs to be improved in detecting heavy metals. In response to the above problems, this paper built a Hydride Generation-Solution Cathode Glow Discharge spectroscopy measurement system to achieve simple and efficient detection for trace mercury (Hg) and tin (Sn) in water. In order to obtain a better detection effect, 270.64 and 253.65 nm were selected as the characteristic analysis lines of Sn and Hg in the experiment. The parameters of the excitation source are configured as the distance between electrodes of 3.5 mm, the discharge current of 60 mA, and the electrolyte flow rate of 2.12 mL·min^-1. At the same time, in the experiment, the relevant experimental conditions affecting the hydride reaction were studied, and the optimal sodium borohydride concentrations of Sn and Hg were 2% and 1.5%, the carrier gas flow rate was 141.50 and 183.95 mL·min^-1, and the pH value of the sample solution is 1.0. Subsequently, in order to further analyze the influence of coexisting ions in the water on the detection performance of the system, the experiment evaluated Pb²⁺, Ca²⁺, Zn²⁺, Cr³⁺, Cd²⁺, Na⁺, K⁺, Mn²⁺, Mg²⁺, Fe³⁺ and Cu²⁺ on the Hydride Generation-Solution Cathodic Glow Discharge technology detects the interference of Sn and Hg. The results show that only Cu²⁺ interferes significantly with detecting two elements. At the same time, Pb²⁺ interferes with detecting Hg to a certain extent, and other coexisting metal ions show no obvious interference. Based on the optimization of the above experimental conditions, the Sn and Hg calibration models were established using the standard external method under the best experimental parameters, and the detection limits of Sn and Hg were calculated to be 6.85 and 1.05 μg·L^-1. The relative standard deviations were all less than 3% ( n=10). The above results indicate that the Hydride Generation-Solution Cathode Glow Discharge technology shows good analytical performance in detecting Sn and Hg. Moreover, this method has the advantages of small size, low cost, and strong anti-interference ability, and it is expected to provide a simpler and more efficient method for detecting heavy metals in water bodies.