Matrix effects during laser ablation MC ICP-MS analysis of boron isotopes in tourmaline

Laser ablation multi-collector inductively coupled plasma mass spectrometry (LA MC ICP-MS) and secondary ion mass spectrometry (SIMS) were used to determine the boron isotopic compositions of several natural tourmaline group minerals (elbaite, schorl and dravite). This study reports on the effects of instrument parameters of LA MC ICP-MS and the composition of sample matrix on data accuracy, reproducibility and repeatability. We demonstrate that the tourmaline matrix has a significant effect on the obtained δ11B values and impacts on data accuracy, with a bias of up to ca. 2.5‰ if a non matrix-matched reference material is used to calibrate the measurements. In the case of a matrix-matched calibration, the boron isotopic data obtained by LA MC ICP-MS are comparable to the reference TIMS values, with typical repeatability for δ11B results between 0.2 and 0.5‰ (1s). This is somewhat better compared to the repeatability of 0.8–1.3‰ (1s) for small format single collector SIMS.