基于便携式光谱仪的溶液阴极辉光放电发射光谱检测水体中的锰

溶液阴极辉光放电-原子发射光谱是一种新颖的快速、高效、实时在线的元素分析方法，它可用于水体金属元素的检测。为了实现对水体中Mn元素准确和稳定的测量，采用溶液阴极辉光放电-原子发射光谱法耦合三台不同入射狭缝和分辨率的便携光谱仪(Maya 2000 Pro)对溶液中的Mn离子进行了检测。实验研究了光谱仪的入射狭缝和分辨率对光谱检测的影响，发现光谱仪的入射狭缝越宽光谱强度越大，光谱仪的分辨率越高得到光谱强度与背景强度的比值越高。实验考察了溶液流速和放电电流对Mn发射光谱的影响，在溶液流速为1.86 mL·min-1和放电电流为65 mA时获得较高信背比。实验测试了在溶液流速为1.86 mL·min-1和放电电流为65 mA的优化实验条件下Mn的光谱检测稳定性，三台便携式光谱仪测量Mn在连续一段时间内光谱强度的相对标准偏差分别为0.59%，0.61%，0.80%，检测的稳定性较好。同时探讨了Mn元素的分析性能参数，获得了较低的背景标准偏差，检出限分别为42.8，65.1，33.8 μg·L-1。实验对标定物质中的Mn元素进行定量分析测量，测量误差在0.02%~2.08%之间，精密度为0.63%~1.54%，加标回收率为97%~99%，表明本方法具有较高的检测准确度和稳定性。研究结果显示，溶液阴极辉光放电-原子发射光谱法耦合便携式光谱仪可用于水体中痕量重金属元素Mn的精确检测。

Analysis of Metal Elements Manganese Using Solution Cathode Glow Discharge-Atomic Emission Spectrometry with Portable Spectrographs

Solution Cathode Glow Discharge-Atomic Emission Spectrometry (SCGD-AES) is a novel rapid, high efficient and real-time online element analysis method, which can be applied to metal elements detection in water. In order to achieve accurate and stable measurement of Mn elements in water, solution cathode glow discharge-atomic emission spectrometry coupled with portable spectrographs (Maya 2000 Pro) were used for the detection of manganese elements in aqueous solution in this paper, and three portable spectrographs with different entrance slit and resolution were employed for the determination. The influence of the entrance slit and resolution of the spectrograph on the spectral detection were studied experimentally, the results showed that the intensity of spectral lines increased when the entrance slit increased. The higher the resolution of the spectrograph was, the higher the ratio of spectral intensity to background intensity was was also concluded. The effects of solution flow rate and discharge current on the emission spectrum of manganese were investigated, and a higher signal background ratio was obtained at a flow rate of 1.86 mL·min-1 and a current of 65 mA. The spectral detection stability of manganese under optimized experimental conditions with flow rate at 1.86 mL·min-1 and discharge current at 65 mA was tested, and the relative standard deviations (RSDs) of the three portable spectrographs for measuring the spectral intensity of Mnin a continuous period of time were 0.59%, 0.61%, 0.80% respectively, showing that the stability of detection is good. The analytical performance parameters of manganese were also discussed, and the limit of detection were 42.8, 65.1, 33.8 μg·L-1, respectively. The manganeseelement in the calibration substance was quantitatively analyzed, andthe error range was 0.02%~2.08%, the precision ranged from 0.63%~1.54% and the recovery rate of samples was 97%~99%, which indicates that the method has high accuracy and stability. The results show that the solution cathode glow discharge-atomic emission spectrometry coupled with portable spectrographis a useful technique for accurately detecting trace manganese elements in aqueous solution.