溶液中铬元素的激光诱导击穿光谱检测

Detection of Chromium in Solution by Laser Induced Breakdown Spectroscopy

采用激光诱导击穿光谱(LIBS)技术对含铬污水溶液中的重金属元素铬开展了探测实验。根据一系列含铬浓度不同的污水样品的LIBS实验结果,获得元素浓度和强度之间的关系曲线,即定标曲线。对CrⅡ(283.43nm)及CrⅠ(425.45nm)两处谱线进行了分析和比较。实验发现,283.43nm处原子辐射信号强度比425.45nm谱线强2倍;从定标曲线的线性相关度及信背比来看CrⅡ(283.43nm)谱线要优于CrⅠ(425.45nm)。计算二者检测限,质量浓度分别为80μg/mL(283.43nm)及170μg/mL(425.45nm)。实验采用CrⅡ(283.43nm)的定标曲线对含铬污水溶液进行了定量分析,测得该污水溶液的含铬质量浓度为333μg/mL,与采用原子吸收分光光度计所得到的检测结果(309μg/mL)符合较好。结果表明,在对铬元素进行LIBS检测时选用CrⅡ(283.43nm)谱线要优于CrⅠ(425.45nm)谱线。采用LIBS方法可实现对污水溶液中Cr元素的快速检测,具有很好的应用前景。

Heavy metal element chromium in sewage solution is detected by laser induced breakdown spectroscopy（LIBS）.The spectral lines of Cr element are obtained.The calibration curve of the line intensities versus the concentrations of Cr element is acquired by experiment.Atomic lines of CrⅡ（283.43 nm） and CrⅠ（425.45 nm） are analyzed and compared.The experimental results show that the intensity of atomic emission line of CrⅡ（283.43 nm） is three times as large as that of CrⅠ（425.45 nm）.The linear correlation coefficient of calibration curve and signal-to-background ratio for CrⅡ（283.43 nm） are better than those of CrⅠ（425.45 nm）.The LIBS detection limit of Cr in the solution is 80 μg/mL（283.43 nm） and 170 μg/mL（425.45 nm）.The calibration curve for CrⅡ（283.43 nm） has been used for quantification of Cr in sewage solution,and the concentration of Cr is found to be 333 μg/mL.This result is compared with Cr concentration obtained by atomic absorption spectrometry（309 μg/mL）,and a close agreement is found.This study indicates that the atomic line of CrⅡ（283.43 nm） is better than CrⅠ（425.45 nm） for LIBS detection.The LIBS technique can be applied in the rapid detection of Cr element in sewage and has good application prospects.