Analysis of DIC & DOC in Water by TIC/TOC-IRMS

The SIF provides ¹³C isotope analysis of dissolved inorganic C and dissolved organic C using a TIC/TOC analyzer system interfaced to an IRMS.

Analysis

DIC and DOC are analyzed for ¹³C using an O.I. Analytical Model 1010 TOC Analyzer (OI Analytical, College Station, TX) interfaced to a PDZ Europa 20-20 isotope ratio mass spectrometer (Sercon Ltd., Cheshire, UK). A 20-mL aliquot of sample is transferred into a heated digestion vessel and reacted sequentially with phosphoric acid then with sodium persulfate to convert DIC and DOC each into a pulse of CO₂. The two sequential CO₂ pulses liberated by the chemical treatments are carried in a helium flow to an infra-red gas analyzer (IRGA), then to the isotope ratio mass spectrometer where the ¹³C/¹²C ratios are measured and compared to ratios of laboratory standards calibrated against NIST Standard Reference Materials.

Pricing

Sample Preparation

The SIF does not accept water samples preserved with mercuric chloride (HgCl₂). We suggest collecting water in 50 mL polypropylene centrifuge tubes and preserving your samples by freezing. Remember to leave a small headspace when freezing to avoid vial breakage. All water samples should be filtered through a 0.4 micron filter. Prior to analysis, water samples will be transferred to 40 mL ICHEM 200 series glass bottles.

Shipping

Group samples in ziplock bags to help prevent leaking boxes. Carefully package samples in an insulated box or cooler with dry ice or ice blocks. Coolers will not be returned.

Analysis Order Form

Please include an Analysis Order Form with any samples you deliver to the Stable Isotope Facility. The SIF uses this form to track your samples and to contact you regarding receipt of samples, data, and invoicing. For mixed analysis requests, we recommend completing a separate form for each type of analysis.

Shipping and contact information:
David Harris
UC Davis Stable Isotope Facility
Department of Plant Sciences
One Shields Avenue, Mail Stop 1
Davis, CA 95616
USA

Phone:(530) 754-7517, Fax: (530) 752-4361
E-mail: dharris@ucdavis.edu

Supplies

References

St. Jean, G. 2003. Automated quantitative and isotopic (¹³C) analysis of dissolved inorganic carbon and dissolved organic carbon in continuous flow using a total organic carbon analyzer. Rapid Communications in Mass Spectrometry 17: 419-428

Tips

-Do not freeze water samples that are in glass i-Chem vials. The vials will break during freezing and your samples will be lost.