Automation of boron chromatographic purification for δ B analysis of coral aragonite.

Rationale: To detect the small changes in past pH the boron isotope ratio of coral carbonates, expressed as the δ B value, needs to be both precise and accurate (2sd <<1‰). Boron measurements by Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS) require the boron to be carefully purified before analysis, which is time consuming, and requires specialist training. Here, we use the prepFAST-MC method that enables the automatic extraction of B (up to 25 ng load) from a CaCO matrix.