The analysis of geological samples using laser-induced breakdown spectroscopy (LIBS) is strongly affected by matrix effects. To investigate the improvement of matrix effects by the graphite doping method, rock powder was mixed with graphite powder and pressed into pellets. Four groups of samples with the same graphite content were prepared from a mixture of seven different rock powders and four graphite powders (0, 25, 50, and 75 wt.%). To reduce some of the pulse-to-pulse fluctuations, the internal standardization method was adopted. Four sets of calibration curves of Ca and Mg were prepared using pellet samples with the same graphite content. The influence of graphite content on laser-induced plasma temperature and electron density was further investigated. The coefficients of determination (R²) of the calibration curves after doping graphite are larger than those without doping, and the stability of the spectral intensity, plasma temperature, and electron density after doping are also improved. In particular, when the doping percentage is 50%, the matrix effect is significantly improved. The results show that the graphite doping method has great potential for improving the matrix effects of LIBS in the analysis of rock powder samples.

使用激光诱导击穿光谱法（LIBS）对地质样品进行分析受到基质效应的强烈影响。为了研究通过石墨掺杂法改善基质效应的方法，将岩粉与石墨粉混合并压制成颗粒。从七种不同的岩石粉末和四种石墨粉末（0、25、50和75 wt。％）的混合物制备具有相同石墨含量的四组样品。为了减少一些脉冲间的波动，采用了内部标准化方法。使用具有相同石墨含量的颗粒样品制备了四组钙和镁的校准曲线。进一步研究了石墨含量对激光诱导等离子体温度和电子密度的影响。测定系数（R ²掺杂石墨后的校准曲线的）大于未掺杂石墨时的校准曲线，掺杂后的光谱强度，等离子体温度和电子密度的稳定性也得到了改善。特别地，当掺杂百分比为50％时，基质效应显着改善。结果表明，石墨掺杂方法在改善岩粉样品分析中LIBS的基体效应方面具有巨大潜力。