Application of 10¹³ Ω amplifiers in low-signal plasma-source isotope ratio measurements by MC-ICP-MS: a case study with Pt isotopes

Recent developments in amplifier hardware enable low-noise measurements of exceedingly small ion beams in isotope ratio analysis, yielding higher precision from smaller samples than ever before. To date, these amplifiers have largely been employed in thermal ionisation instruments, with few applications using plasma-source (i.e., MC-ICP-MS) instruments. Here, we demonstrate the utility of these new generation 10¹³ Ω amplifiers in MC-ICP-MS, employing Pt isotopes as a case study, a system that could greatly benefit from the promised advances. The data demonstrate that for samples with low Pt abundance, for a modest increase in uncertainties, the amount of sample required can be reduced by a factor of 50–100. This technique thereby opens up new possibilities for analysis of samples that have low Pt mass fractions or were otherwise impossible to obtain in sufficient quantities.