Service Provided: Simultaneous determination of carbon and nitrogen and/or sulfur content and stable isotope ratios for solid samples by Elemental Analysis - Isotope Ratio Mass Spectrometry (EA-IRMS). Samples can be prepared and delivered to the MSI Analytical Lab for analysis (reach out to MSI Analytical staff to determine proper sample amounts) or can be prepared in-house, including weighing and encapsulation of samples into tin capsules. Additional preparatory services may be available on request, including sample grinding, acidification, and drying.
Technique Used: Automated Organic Elemental Analyzer (Dumas combustion method)
Measurement Range and Precision:
| Analyte | Optimal Range | Detection Limit | Precision |
|---|---|---|---|
| Carbon, δ13C | 100 - 250 µg | 10 µg | +/- 0.1 ‰ |
| Nitrogen, δ15N | 20 - 80 µg | 10 µg | +/- 0.2 ‰ |
| Sulfur, δ34S | 15 - 30 µg | 5 µg | +/- 0.2 ‰ |
Instruments
*Awarded through NSF's Major Research Instrumentation Program (MRI) in 2023
Award No: 2320674
EA - IRMS
- Manufacturer: Thermo Fisher Scientific, Thermo Finnigan
- Model: *Flash EA IsoLink CN with a Thermo Delta plus Advantage IRMS
- Features
- Individual or simultaneous δ15N, δ13C, and δ34S analysis on solid samples
- Ramped GC-oven for improved elemental separation
- Customized for low concentration δ34S analysis
We can analyze C, N, and S isotopes from a variety of solid substrates, including organics, soils, and sediments. The EA can either be run with a dual reactor for C & N analysis or in single reactor mode for analyses with S. After high temperature combustion, reaction products N2, CO2, and SO2 pass through a ramped GC oven to sharpen peaks. Downstream hardware components are treated with a SulfinertⓇ coating to reduce S carry-over effects.
Samples should be dry and homogenized before sending to MSI AL. We typically weigh and encapsulate samples in tin in-house; we offer a discount for analysis of pre-encapsulated samples. If submitting prepared samples, please double check with AL staff to ensure the
Some substrates likely contain both organic and inorganic C—such as marine sediments, rock powders, or soils. In this case, it may be necessary to acidify sample material to remove inorganic C from the analysis. However, acidification can produce a δ15N offset; in this case, individual samples for either δ13C (decarbonated) and δ15N (regular) analysis may be recommended. Large S samples perform better with interspersed blanks to mitigate carry-over effects.
Please reach out to the analytical lab personnel for in-depth questions on sample preparation, capabilities, and instrument availability.
Rates
Recharge rates for both UC and non-UC researchers cover the cost of sample prep and analysis. A discount of 20% is applied for pre-weighed samples. Non-routine services such as grinding, acidification for POC, or difficult to combust samples will incur additional charges. Priority services are available upon request. Rates are adjusted annually.
| Analytical Service Provided | UC Rate | Non UC Rate | ||
|---|---|---|---|---|
| Isotope Ratio Mass Spectrometry | ||||
| δ13C, δ15N, *δ34S (*additional charges apply for δ34S measurements) | $23.00 | $36.00 | ||
|
|
||||
| Lab Personnel Labor Rates | ||||
| Analytical Lab Group rate (per hour) | $95.00 | $149.00 | ||