Copper Isotope Compositions Measured Using a Sapphire Dual Path MC-ICPMS with a Collision/Reaction Cell.

We present a new approach to Cu isotopic measurements using a state-of-the-art Nu Sapphire multicollector inductively coupled plasma source mass spectrometer equipped with a collision/reaction cell (CRC-MC-ICPMS). We investigate the effects of Na doping and Cu concentration mismatch between bracketing standard and unknown samples and demonstrate the efficacy of introducing a He-H gas mix into the CRC to efficiently eliminate the sample matrix-based ArNa isobaric interference on Cu. This capability is crucial when measuring samples with high Na/Cu ratios, such as some biological samples, which have significantly different chemical compositions compared to most geological samples.

Multispecies in situ monitoring of a static internal combustion engine by near-infrared diode laser sensors.

A multispecies near-infrared diode laser spectrometer has been constructed for measurements of carbon monoxide, carbon dioxide, and methane directly in the exhaust of a static internal combustion engine. A wavelength modulation-division multiplexing scheme was implemented for the two distributed feedback diode lasers. Gas concentration variations were observed for changes in operating conditions such as increasing and decreasing the throttle, adjusting the air-fuel ratio, and engine start-up.