溶液阴极辉光放电-原子发射光谱法测定富锶矿泉水中的锶

锶元素是人体不可缺少的微量元素，饮用富锶矿泉水可以为人体补充锶。目前用于检测富锶矿泉水中锶元素的常规分析方法如原子吸收光谱法、原子荧光光谱法、离子色谱法、电感耦合等离子体-原子发射光谱法/质谱法等，具有检测灵敏度高、检测稳定性好的优点，但是相关仪器体积庞大，价格昂贵，能耗高，有些还需要使用惰性/特殊气体，不适合现场、实时和在线连续监测。因此，发展小型化、低成本、快速的光谱检测对锶元素的有效测量具有重要意义。溶液阴极辉光放电-原子发射光谱法是近年来发展迅速的水体金属离子测量方法，具有检出限低、成本低、小型化等优点。因此，建立溶液阴极辉光放电-原子发射光谱系统，实现了富锶矿泉水中锶元素的浓度测量。实验考察了溶液阴极辉光放电装置中放电电流、溶液流速和pH值等参数对锶的信背比的影响，确定了定量分析元素锶的最佳实验条件：溶液流速1.85 mL·min-1、溶液阴极辉光放电装置的放电电流75 mA，pH 1.0的HNO₃作为电解质。选取波长为460.77 nm的光谱线作为锶元素的分析谱线。在上述最佳工作条件下对锶的溶液进行测定，锶元素的发射光谱稳定性为0.52% (n=21)。锶的质量浓度在0.1～20 mg·L-1范围内与其发射强度呈线性关系，线性相关系数为0.999 6。所建立的溶液阴极辉光放电-原子发射光谱法测得锶的检出限为29 μg·L-1。采用搭建的溶液阴极辉光放电-原子发射光谱检测系统测量了市场上常见的三种富锶矿泉水，测量结果与电感耦合等离子体发射光谱法一致。此外，该方法对富锶矿泉水的加标回收率为98.8%~107.6%。结果表明：溶液阴极辉光放电-原子发射光谱法是测定富锶矿泉水中锶的一种有效方法。

Determination of Strontium in Strontium-Rich Mineral Water UsingSolution Cathode Glow Discharge-Atomic Emission Spectrometry

Strontium element is an indispensable trace element in the human body,and strontium rich mineral water is an important means of supplementing strontium in the human body.At present,the conventional analytical methods used to detect strontium elements in strontium-rich mineral water,such as AAS,AFS,IC,ICP-AES/MS,etc.,have the advantages of high detection sensitivity and good detection stability.However,these instruments are bulky,expensive,and energy-intensive,moreover some require inert/special gases,which are not suitable for field,real-time and online continuous monitoring.Therefore,it is of great significance to develop a miniaturized,low-cost and rapid spectral detection technology for the effective measurement of strontium.In recent years,Solution cathode glow discharge-atomic emission spectrometry(SCGD-AES)is a rapidly developing for detecting metal elements in an aqueous solution.Here,the SCGD-AES system was established to measure the concentration of strontium in strontium-rich mineral water.The experimental parameters such as discharge current,sample flow rate and pH on the SBR of strontium were investigated,and the optimal experimental parameters for quantitative analysis of strontium were as follows:1.85 mL·min^-1 for the sample flow rate,75 mA for the discharge current,and the electrolyte acidified to pH 1.0 by HNO₃.460.77 nm was selected as the strontium analytical spectrum line,and the strontium solution was determined under the above optimal working conditions.The emission spectral stability of strontium was 0.52%(n=21).The strontium concentration shows a linear relationship with its emission intensity in the range of 0.1~20 mg·L^-1,and the linear correlation coefficient is 0.9996.The detection limits of strontium were 29μg·L^-1 for the homemade SCGD-AES.The established SCGD-AES detection system measured three types of strontium-rich mineral water in the market,and the results were agreed with the results of inductively coupled plasma-atomic emission spectrometry.In addition,the recoveries of bottled mineral water are 98.8%~107.6%.The results show that SCGD-AES is an effective method for the determination of strontium in strontium-rich mineral water.