利用一台小型Nd:YAG调Q激光器,在常压大气环境下诱导激发标准岩石等离子体,通过分析微光谱仪收集记录的等离子体发射光谱来定量分析样品中部分元素含量。选择Si元素作为内标元素,根据分析线与内标线的相对强度比,分别对岩石中的Mg元素和Ca元素建立不同的定标曲线。在实验条件相同且无光谱干扰的条件下,元素含量比的对数值与光谱线总强度比的对数值之间有很好的线性关系,其定量分析曲线的拟合度R最小值为0.996,测得相对标准偏差(RSD)的最大值为6.5%。研究结果表明,利用强度归一化法定量分析岩石主要元素含量在一定程度上可以提高测量准确度。

Plasma is generated from standard rock samples by using a small Nd:YAG Q-switched laser under the atmospheric environment. Concentrations of some elements in the samples are determined by analyzing the plasma emission spectra collected by a miniature spectrometer. Silicon element is selected as internal standard and calibration curves for the magnesium and calcium elements in rock samples are drawn,respectively,based on peak intensity ratios of analysis elerment to the internal standard element. The results show that,if all the measurements are conducted under the same conditions and no line interference occurs to the spectral lines concerned,a good logarithmic linearity between the ratios of element concentrations and the ratios of corresponding relative peak intensity can be found. The minimal degree of fitting (R) value is 0.996 and the maximal relative standard deviation (RSD) value is 6.5% for quantitative elemental analysis. The accuracy for the quantitative analysis of main elements in the rocks can be improved by means of the intensity normalization method.