Laser ablation multi-collector-inductively coupled plasma-mass spectrometry (LA-MC-ICP-MS) has become a valuable tool for the in situ measurement of the boron isotope composition of geological samples at high (tens to hundreds of μm) spatial resolution. That said, this application suffers from significant analytical challenges. We focus in this study on the underlying processes of two of the main causes for inaccuracies using this technique. We provide empirical evidence that not only Ca ions (Sadekov et al. 2019, Standish et al. 2019, Evans et al. 2021) but also Ar ions, that are reflected within the flight tube of the mass spectrometer, are the source for previously reported issues with spectral baselines. We also address the impact of plasma conditions on the instrumental mass fractionation as a source for matrix- and mass-load-related analytical biases. Comparing experimental data with the results of a dedicated release and diffusion model (RDM) we estimate that a close to complete (~ 97%) release of boron from the sample aerosol is needed to allow for consistently accurate LA boron isotope measurement results without the need for corrections.

中文翻译：

---

使用 LA-MC-ICP-MS 进行硼同位素测量的不准确性来源

激光烧蚀多接收器电感耦合等离子体质谱仪 (LA-MC-ICP-MS) 已成为高空间分辨率（数十至数百微米）原位测量地质样品硼同位素组成的重要工具。也就是说，该应用程序面临着重大的分析挑战。我们在这项研究中重点关注使用该技术导致不准确的两个主要原因的基本过程。我们提供的经验证据表明，不仅 Ca 离子（Sadekov et al . 2019、Standish et al . 2019、Evans et al.。2021），而且在质谱仪飞行管内反射的 Ar 离子也是先前报道的光谱基线问题的根源。我们还解决了等离子体条件对仪器质量分馏的影响，作为基质和质量负载相关分析偏差的来源。将实验数据与专用释放和扩散模型 (RDM) 的结果进行比较，我们估计需要从样品气溶胶中接近完全 (~ 97%) 释放硼，以实现一致准确的 LA 硼同位素测量结果，而无需以便更正。