High-precision, mass dependent Si isotope measurements the critical mixture double-spiking technique.

We have developed a new method for measuring mass dependent Si isotope fractionation critical mixture double-spiking. Samples need to be spiked before column chemistry to guarantee full equilibrium between the sample and double-spike (Si-Si spike). An iterative addition of the double-spike to the sample, usually 2-4 times, is needed to generate a solution very close to the critically spiked mixture.

Diet, cellular, and systemic homeostasis control the cycling of potassium stable isotopes in endothermic vertebrates.

The naturally occurring stable isotopes of potassium (41K/39K, expressed as δ41K) have the potential to make significant contributions to vertebrate and human biology. The utility of K stable isotopes is, however, conditioned by the understanding of the dietary and biological factors controlling natural variability of δ41K. This paper reports a systematic study of K isotopes in extant terrestrial endothermic vertebrates.

Project Vienna: A Novel Precell Mass Filter for Collision/Reaction Cell MC-ICPMS/MS.

The last decade has seen widespread adoption of triple quadrupole-based inductively coupled plasma-tandem mass spectrometry (ICPMS/MS) technique using a collision/reaction cell in combination with a precell bandpass mass analyzer to measure isotopes otherwise masked by spectral interferences. High-precision isotope ratio analysis containing such isotopes would benefit from a similar capability on a multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) platform, but using a quadrupole-based precell mass analyzer for MC-ICPMS/MS has several limitations. To overcome these limitations, we developed a novel precell mass analyzer for MC-ICPMS/MS using sector field technology.

Rb-Sr dating by collision cell, multicollection inductively-coupled plasma mass-spectrometry with pre-cell mass-filter, (CC-MC-ICPMS/MS).

We document the utility for Rb-Sr dating of a one-of-a-kind tribrid mass spectrometer, 'Proteus', coupled to a UV laser ablation system. Proteus combines quadrupole mass-filter, collision cell and sector magnet with a multicollection inductively-coupled plasma mass spectrometer (CC-MC-ICPMS/MS). Compared to commercial, single collector, tribrid inductively-coupled plasma mass spectrometers (CC-ICPMS/MS) Proteus has enhanced ion transmission and offers simultaneous collection of all Sr isotopes using an array of Faraday cups.

Primordial formation of major silicates in a protoplanetary disc with homogeneous Al/Al.

Understanding the spatial variability of initial Al/Al in the solar system, i.e., (Al/Al), is of prime importance to meteorite chronology, planetary heat production, and protoplanetary disc mixing dynamics.