【摘要】 激光诱导击穿光谱作为一种新型的物质成分检测技术,具有快速、实时、微损、原位、多元素同时分析等优势,目前在环境监测,食品安全,选矿冶金,生物医疗,太空探测等多个领域都具有广泛应用。然而,由于元素谱线的自吸收效应,使得激光诱导击穿光谱谱线强度降低,严重时甚至会使特征谱线峰型产生凹陷(即"自蚀"现象),定标曲线变弯曲,导致该技术的元素检测精准度变差,从而无法实现大规模商业应用。因此,对激光诱导击穿光谱自吸收效应及其校正方法的探索,一直以来是学者们研究的热点。综述了自吸收效应校正方法的研究进展,分析了自吸收效应产生的物理机制,分别从实验参数优化、物理辅助装置、自吸收模型和校正算法等多个角度对自吸收效应的几种主要校正方法进行了归纳和总结,并对其优势和缺点进行了对比分析,其中实验参数优化具有原理简单、易操作的优势;能态选择性共振激发自吸收效应抑制效果稳定;微波辅助激发成本较低,可同时对多元素实现自吸收抑制;自吸收系数法可直接量化自吸收效应强弱,计算步骤简便且所需等离子体参数较少;基于内参考线的自吸收校正算法计算效率高,校正效果明显;光学薄法可直接获取光学薄等离子体谱线,避免理论误差。最后,对自吸收效应未来的研究方向和发展趋势进行了展望。更多还原

【Abstract】 Laser-induced breakdown spectroscopy(LIBS), as a new material composition detection technology, has lots of advantages such as rapid, real-time, micro-damage, in-situ, multi-element analysis and so on. At present, it has been widely used in environmental monitoring, food safety, mineral processing and metallurgy, biomedicine, space exploration and other fields. However, due to the self-absorption, the spectral intensity is reduced. In severe cases, the line profile is even sunken in the centrum(“self-reversal”). The linear coefficient of calibration curve decreases, resulting in the deterioration of the accuracy of element detection, so that large-scale commercial applications cannot be realized. Therefore, the exploration of the self-absorption effect and its correction methods has always been the research hotspot. In this review, the progress of the correction method and the physical mechanism of self-absorption are reviewed. The main correction methods are summarized from the perspectives of experiment parameters optimization, physical assist device, self-absorption model and correction algorithm, respectively. The advantages and disadvantages of the primary correction methods are compared and analyzed. The experiment parameters optimization has the advantages of simple principle and operation. The effect of self-absorption reduction of laser stimulated absorption LIBS(LSA-LIBS) is stable. Microwave assisted excitation LIBS(MAE-LIBS) can reduce the self-absorption effect of multiple elements simultaneously and cost low. The self-absorption coefficient method can directly quantify the degree of self-absorption effect, has simple calculation steps and requires less plasma parameters. The self-absorption correction algorithm based on internal reference line has high calculation efficiency and obvious correction effect. Optically thin method can directly obtain optically thin spectral lines to avoid theoretical errors. Finally, the future research direction and development trend of self-absorption is prospected in our opinion.更多还原