Latest improvements in field deployable compound specific isotope analyzer based on quantum cascade lasers and hollow waveguide

In our development of a field deployable infrared isotope ratio spectrometer (IR2) for compound specific isotope analysis (CSIA), the IR2's accuracy and stability have reached a stage that small fractionation in reference gas pulses generated as standard are observed easily and repeatedly. Such fine fractionation is often difficult to observe in regular Isotope Ratio Mass Spectrometer (IRMS) due to instrument drift on the order of 10s of minutes. After careful design of reference pulse sequences and long period of data collection, such fractionations are also verified in a commercial continuous flow CSIA-IRMS. Implications of the fractionation and observation process are discussed.