CO2-laser extraction-static mass spectrometry analysis of ultra-low concentrations of nitrogen in silicates

A new installation for the analysis of picomole quantities of nitrogen has been designed and constructed. It permits the simultaneous analysis of N an d rare gases extracted from silicates by heating. The extraction procedure involves the use of a CO2 laser as a heater, and the analysis is made by st atic mass spectrometry using a high sensitivity high resolution mass spectr ometer. Procedural blanks of similar to 2 picomoles N-2 (60 picogram N) all ow us to analyse routinely N in mg-sized samples such as mantle-derived and meteoritic minerals, and Lunar soil grains.