Delta V+ Isotope Ratio Mass Spectrometer
CASIF measures stable isotope ratios of carbon, nitrogen, hydrogen, and oxygen in environmental samples of solids, liquids, and gases using Thermo Fisher Delta V+ isotope ratio mass spectrometer interfaced with various peripheral devices.
The Delta V+ has a universal triple collector (for C, N, and O) and a H2 collector with two additional faraday cups for m/z 2 and 3.
The appropriate reference gases as well as sample gases enter the mass spectrometer via a Conflo IV Universal Interface from Thermo Fisher.
The GasBench II is a continuous flow preparation device and inlet system with repetitive loop injection of gases. CASIF has two Gas Benches; one is used for measuring isotopes of nitrogen and oxygen in dissolved nitrate via the denitrifier method (including d17O) and the other measures isotopes of carbon and oxygen of carbonates and dissolved inorganic carbon (DIC).
CASIF uses a Carlo Erba NC 2500 Elemental Analyzer with a Costech zero-blank autosampler for analysis of carbon and nitrogen isotopes in solid organic samples, such as leaf tissue, wood, animal tissue, filters, and soil. Modifications permit analysis of samples with <0.5% N such as wood and low organic-content soil and sediment.
Temperature Conversion Elemental Analyzer
CASIF uses a Temperature Conversion Elemental Analyzer (TC/EA) from Thermo Fisher to measure hydrogen and oxygen isotopes in solid organic compounds, such as wood and animal tissue.
The spooling wire microcombustion device is based on a design introduced by Brand and Dobberstei (1996), and then optimized Sessions (2005), for analysis of carbon isotopes in nonvolatile organic compounds. The instrument at CASIF is primarily used for analysis of pollen grains.