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Skidmore College
Stable Isotope and Palæoclimate Analysis Laboratory

MAT-253 Gas Isotope Ratio Mass Spectrometer

MAT 253 Gas Isotope Ratio Mass Spectrometer

The MAT-253 gas isotope ratio mass spectrometer is the central piece of analysis equipment in the lab.  It ionizes single gases of interest (usually, H2, N2, CO2, and SO2) under a general vacuum, hurtles the resulting ions around a curve using magnetic fields, and measures the relative abundance of isotopes in a given sample via the mass-to-charge ratio of the ionic gas ascertained by the particular faraday collector that the ion hits.  Three peripheral devices are connected to produce relatively pure gas from sample material: a Kiel IV, a GasBench II, and a ECS 4010 Elemental Analyzer.  Isotope ratio analysis on those peripherals requires the MAT-253.  The SPA lab MAT-253 has a 5 cup CNOS detector and a 2 cup H/D collector allowing detection of gases with m/z 2-3, 18, 28-30, 40, 44-46, 64 and 66.  Thus, this IRMS is tuned to the analysis of stable isotopes.  The MAT-253 consumes 0.031 nmol/s for 1.5 V signal (5 nA) at mass 44 in dual inlet mode and 0.047 nmol/s for 1.5 V signal (5 nA) at mass 44 in a continuous flow mode.