激光剥蚀等离子体质谱分析中激光剥蚀参数对信号响应的影响

The Effects of Laser Ablation Operating Parameters on Signal Response in LA-ICP-MS Microanalysis

探讨了激光剥蚀等离子体质谱固体微区分析中激光剥蚀参数对元素分析信号灵敏度及稳定性的影响.这些参数包括激光功率、脉冲频率、剥蚀孔经、散焦距离、剥蚀方式等.讨论了优化的激光剥蚀等离子体质谱信号采集及数据处理方式.在全质量范围内选用具有代表性的元素作为研究对象,建立了激光剥蚀的一般性特征规律和266 nm紫外激光系统的最佳操作条件.在选定的激光剥蚀参数下,大多数被测元素的检出限为22.8～457 ng/g,能够满足固体微区分析的要求.

The effects of laser ablation operating parameters on sensitivity and stability of signal response in solid microanalysis by LA-ICP-MS technique have been respectively investigated. These parameters involve laser power, pulse frequency, spot size, defocus distance and ablation modes, etc. The optimized method for data acquisition of transient signal and data reduction in LA-ICP-MS has been discussed. Five typical elements including ^42Ca, ^59Co, ^139La, ^159Tb, ^232Th were selected as the representatives of signal response in all range of mass. The general characteristics in laser ablation were illustrated and the optimum operating conditions of 266 nm UV laser system were established. The proposed laser ablation parameters condition has been applied to analysis of NIST glass standard references （NIST SRM 610,612） , and the detection limits of most elements are in the range of 22.8 -457 ng/g. This method can be used for the quantitative solid microanalysis.