电感耦合等离子体质谱（ICP-MS）测定地质样品中稀土元素的过程中，尤其对于高Ba基体的地质样品，由Ba形成的氧化物和氢氧化物离子对Eu元素会产生质谱峰的重叠干扰，严重影响Eu测定结果的准确度和精确度。通过标准溶液的条件实验，测定Ba干扰项相对Ba总量的比例（干扰率）并进行相应的Eu扣除，是一种解决干扰导致Eu测定结果偏高的思路。然而该干扰率在不同基质溶液中是否一致，且随着Ba含量变化是否稳定目前尚不明确。本文通过对不同基体溶液中Ba对Eu干扰率的测定（低分辨模式测定），发现随着溶液中Ba浓度的变化，同一基体溶液中该干扰率较为恒定，而不同基体溶液中干扰率有明显的差别。这说明在对Eu测定结果进行干扰扣除时，需要利用匹配的基体溶液来获取准确的Ba干扰率。应用这种方法扣除得到的Eu结果与质谱的高分辨模式（R=10000）下的测定结果较为一致，数据的重现性也较为理想。因此，利用基体匹配的方式来进行Ba对Eu的数学扣除是一种可行的方法。%Precise and accurate determination of Europium concentration in geological sample using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is hindered by severe spectroscopic overlap of BaO + and BaOH + ions. Correction for Eu concentration mathematically based on precise determination of (BaO++BaOH+)/Ba ratios is an applicable method. However, whether the ratios vary with varying matrix and Ba concentrations remain uncertain. In the current study, we investigated variations in (BaO+ +BaOH+)/Ba ratios in solutions by changing matrix and Ba contents in analyzed solutions. The results show that during the course of measurement, when keeping constant the matrix in solutions, the ratios are almost invariant at different Ba concentrations. In contrast, the matrix of solution has a major impact on the (BaO++BaOH+)/Ba ratios. Corrected Eu concentrations using the (BaO++BaOH+)/Ba ratios obtained are comparable to results obtained using high resolution mode(R=10000), with replicate analysis showing good reproducibility. The results show that using matrix-matching solution is essential for mathematical correction of Eu concentration.
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