Development of an instrument for the chemical and isotopic analysis of sub-nanomole quantities of gas from individual fluid inclusions, microfossils and biological tissues using mass spectrometry

Abstract

A micro-volume thermo-electronically-cooled trapping device (TEC trap) was designed and built to trap and facilitate subsequent analysis of sub-nanomole quantities of gas. The TEC trap was used with an elemental analyzer - isotope ratio mass spectrometer (EA-IRMS) to provide fully automated carbon-13 analyses of microfossil samples containing less than 100 times material than that required for conventional EA-IRMS analyses. A fully-automated small-sample preparation system incorporating the TEC trap was designed and built to further reduce minimum sample-size requirements for stable isotope analysis without compromising data quality or ease-of-use for large sample batches. This new sample preparation system provided carbon-13 analyses of microscopic animals, more than 100 times below the normal minimum sample-size limits of conventional EA-IRMS equipment while maintaining a precision of better than 0.2 permil. A cryogenically-cooled micro-volume trapping device was designed and built to trap a wider range of gases than the TEC trap and to permit fractional release of the trapped gases. The anticipated outcome of the use of this trap is to allow the analysis of the gaseous contents of a single 10 um fluid inclusion. These devices and techniques have advanced stable isotope research into the microscopic realm and are providing researchers with the ability to investigate individual microscopic organisms and their preserved remains previously beyond the reach of conventional IRMS techniques and equipment.