A Novel Approach for the Simultaneous Determination of Iodide, Iodate and Organo-Iodide for ¹²⁷ I and ¹²⁹ I in Environmental Samples Using Gas Chromatography-Mass Spectrometry

Journal Article · Thu Nov 11 00:00:00 EST 2010 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es102047y· OSTI ID:1154325

Zhang, S.; Schwehr, K. A.; Ho, Y. -F.; Xu, C.; Roberts, K. A.; Kaplan, D. I.; Brinkmeyer, R.; Yeager, C. M.; Santschi, P. H.

In aquatic environments, iodine mainly exists as iodide, iodate, and organic iodine. The high mobility of iodine in aquatic systems has led to ¹²⁹I contamination problems at sites where nuclear fuel has been reprocessed, such as the F-area of Savannah River Site. In order to assess the distribution of ¹²⁹I and stable ¹²⁷I in environmental systems, a sensitive and rapid method was developed which enables determination of isotopic ratios of speciated iodine. Iodide concentrations were quantified using gas chromatography-mass spectrometry (GC-MS) after derivatization to 4-iodo-N,N-dimethylaniline. Iodate concentrations were quantified by measuring the difference of iodide concentrations in the solution before and after reduction by Na₂S₂O₅. Total iodine, including inorganic and organic iodine, was determined after conversion to iodate by combustion at 900 °C. Organo-iodine was calculated as the difference between the total iodine and total inorganic iodine (iodide and iodate). The detection limits of iodide-127 and iodate-127 were 0.34 nM and 1.11 nM, respectively, whereas the detection limits for both iodide-129 and iodate-129 was 0.08 nM (i.e., 2pCi ¹²⁹I/L). This method was successfully applied to water samples from the contaminated Savannah River Site, South Carolina, and more pristine Galveston Bay, Texas.

• Research Organization: DOE Office of Science Subsurface Biogeochemical Research (SBR) (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER)
• OSTI ID: 1154325
• Journal Information: Environmental Science and Technology, Vol. 44, Issue 23; ISSN 0013-936X
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English