等离子体质谱法测定地质样品中痕量稀土元素的基体效应及多原子离子干扰的校正研究

Studies on the Calibration of Matrix Effects and Polyatomic Ion for Rare Earth Elements in Geochemical Samples by ICP-MS

采用模拟地质样品中稀土元素间天然组成比的基体匹配校正标准溶液进行外标校正 ,有效地抑制了地质样品分析中的基体效应 ;以 1 1 5 In-1 0 3Rh双内标元素校正 ,监控和校正分析信号的短期和长期漂移 ;通过单个稀土元素及钡的氧化物、氢氧化物的测定计算出等效的干扰浓度 ,进而校正了稀土元素分析中多原子离子干扰 .建立了地质样品中痕量稀土元素测定中基体效应及多原子离子干扰的校正方法 ,通过对 5个标准参考物质的分析 ,定量测定限为 0 .0 0 9～ 0 .1 33μg· g- 1 ,RSD小于 5% .

The calibration method was developed for the matrix effects and polyatomic ion of the analysis of rare earth elements in the geological samples. Matrix effects were minimized by using synthetic calibration solutions which simulated the composition of natural rocks by statistically calculating the average values of 20 geological samples and normalization. Two separate internal standards of 115 In 103 Rh were selected to compensate the drift of analytical signals. Polyatomic ions were calibrated by measuring the oxides (MO +) and hydroxide (MOH +) with individual La, Ce, Pr and Ba solution for the ratio of MO +/M + and MOH +/M + and calculating equivalently concentrations. The proposed method has been applied to the analysis of AGV 1(Andesite), BHVO 2(Basalt), GSR 3(Basalt), DNC 1(dolerite) and RGM 1(rhyolite). The relative error between this work and the recommend values are better than 10% and the relative standard deviations are better than 5%.