微孔喷射辅助水溶液样品激光诱导击穿光谱在线分析方法研究

Micro Hole Sprayer Assisted Laser Induced Breakdown Spectroscopy for Online Analysis of Trace Metal Elements Dissolved in Water

受到水溶液内部复杂基质效应的影响,激光诱导击穿光谱(LIBS)技术在水溶液样品的连续在线检测分析应用中受到很大制约。提出了一种微孔喷射辅助LIBS的新技术,用以实现水溶液中金属元素的连续在线分析。该方法通过微米量级的小孔矩阵和压电陶瓷振荡片将流动液体在线转化成密集的小液滴并连续喷出来,辅助LIBS系统进行检测。依据此思路,设计实现了一套由微孔喷射装置和传统LIBS装置组成的微孔喷射辅助LIBS检测系统。利用该系统,以水溶液中的Ca元素为目标元素展开实验,研究该方法的最优化实验参数、等离子体物理特性和检测能力等。结果表明,该方法对Ca元素的在线检测限能够达到0.96 mg/L,且在0~1124 mg/L范围内谱峰强度和浓度之间具有较好的线性关系。

Due to the complex matrix effects in bulk water,the application of laser induced breakdown spectroscopy（LIBS） in online continuous detection and analysis of liquid sample is limited. Thus,we propose a new method of LIBS assisted by micro hole spraying technology. The essence of this method is to transform the flowing liquid sample into dense droplets and spurt out continuously through a micron hole matrix and piezoelectric ceramic in order to assist the analysis of LIBS. A detection experimental system is established,composing of a micro hole ultrasonic system,a 1064 nm Nd…YAG laser and a fiber optic spectrometer. A series of experiments and analysis are carried out to detect the calcium element dissolved in pure water with the detection experimental system. The optimum experimental parameters,the physical properties of plasma and the analysis ability of this method are studied. The results show that the limit of detection for calcium element is as low as 0. 96 mg/L. And there is a good linearity between spectral peak intensity and concentration within the range of 0-1124 mg/L.