Rapid determination of boron isotopic composition (δ11B) in pore water by multi-collector inductively coupled plasma mass spectrometry

Abstract

A new method has been developed for the accurate, precise and more rapid determination of boron isotopes (δ¹¹B) by MC-ICP-MS applicable to seawater and pore water samples. Obvious matrix effects have been observed when applying pure standard solutions to bracket the untreated pore water samples and matrix-containing standards. The matrix effects were eliminated by applying matrix-matched standards to measure the matrix-matched ones. The concentration effect of boron has also been investigated and it shows that boron does not exhibit an obvious concentration effect in the concentration range of 50 μg L⁻¹ to 300 μg L⁻¹. Therefore, IAPSO (seawater) was used as the standard to directly measure the untreated pore water and the results are satisfactory. The salient advantage of this method is that there is no need for boron purification procedures and water samples can be directly used for boron isotopic analysis without obvious sacrifice of precision, thus making this protocol more rapid than other ones.