Instruments

Isotope Ratio Mass Spectrometry (IRMS)

Detailed information is coming soon!!

Check out a simple example of how a Stable Isotope Ratio Mass Spectrometer works.

ThermoFisher Delta V

ThermoFisher Delta V is a magnetic sector instrument with an electron bombardment ion source and multiple Faraday cup detectors for measurement of 15N/14N, 13C/12C, and 18O/16O isotope ratios at the natural abundance level up to about 10 times the natural abundance level for high dilution isotope tracer studies.

The instrument has three inlet devices.  A traditional dual is available for the analysis of N2 and CO2 gas for the analysis of 15N/14N, 13C/12C, and 18O/16O isotope ratios. Samples should be provided in stopcock sealed bulbs which can be attached to the inlet preferably as 0.25-inch tubes, although Cajon adaptors for ODs up to 0.5 inches are available.  Gas samples of 0.5 mL STP or larger can be analyzed.

A Gas bench inlet for samples automated analysis is available when gas specimens are provided in Labco Exetainer 15mL rubber or similar elastomer septum sealed tubes.  The Exetainer tubes with no additives can be recycled by replacing the septum and used most often. Samples should be provided as He mixtures with sample gases at 0.4 to 2%.

The third inlet is the EA (elemental analyzer) combustion inlet. Organic samples are to be provided in a dry form and are costed to CO2 followed by a reduction process to convert CO and NO to CO2 and N2, respectively. Samples are placed in clean tin cups for handling. A sample size of 0.5 to 5.0 mg can be introduced using the EA.

The 13C/12C and 18O/16O analyses using the Gas bench inlet typically have precisions of 0.05, and 0.15‰, respectively.  The precisions performed using the EA inlet for 15N/14N, 13C/12C are 0.3 and 0.1‰.

Thermo Scientific Delta V Isotope Ratio Mass Spectrometer its peripheral devices, available in the IRMS Lab.

Thermo Fisher Delta Plus

The Thermo Fisher Delta Plus is also a magnetic sector instrument with an electron bombardment ion source and multiple Faraday cup detectors for measurement of 15N/14N, 13C/12C, 18O/16O, and 2H/1H isotope ratios from the natural abundance level up to about 10 times natural abundance. In practice, our instrument is used almost exclusively for 2H/1H analysis.

The instrument is equipped with a traditional dual gas bellows inlet. Samples should be provided in stopcock sealed bulbs which can be attached to the inlet preferably as 0.25-inch tubes, although Cajon adaptors for ODs up to 0.5 inches are available.  Gas samples of 0.5 mL STP or larger can be analyzed, but this form of sample submission is slower because it requires manual handling.

An autoinjector feeding into a chromium reduction reactor is available for the analysis of water specimens for the analysis of 2H/1H in water. Water samples between 0.2 and 2 g can be accommodated with each analysis consuming about 1 µL of water. The precision for 2H/1H analysis is 1.0‰.

Finnigan DELTA plus Advantage by Thermo Fisher Scientific connected to the autosampler, available in the IRMS Lab.