The long lived radioisotope (129)I is a uranium fission product, and an environmental contaminant... more The long lived radioisotope (129)I is a uranium fission product, and an environmental contaminant of the nuclear age. Consequently, it can trace anthropogenic releases of (129)I in watersheds, and has been identified as a potential means to distinguish water sources in discharge (Nimz, 1998). The purpose of this work was to identify the sources and mass input of (129)I and trace the transport, partitioning and mass balance of (129)I over time in a remote watershed. We monitored (129)I and other geochemical and isotope tracers (e.g. δ(14)CDIC, δ(13)CDIC, δ(2)H, δ(18)O, etc.) in precipitation and discharge from the Wolf Creek Research Basin (WCRB), a discontinuous permafrost watershed in the Yukon Territory, Canada, and evaluated the use of (129)I as a water end-member tracer. Radiocarbon and geochemical tracers of weathering show that discharge is comprised of (i) groundwater baseflow that has recharged under open system conditions, (ii) spring freshet meltwater that has derived solu...
A new method was developed to extract 129I from urine samples and then measure it by AMS. The sam... more A new method was developed to extract 129I from urine samples and then measure it by AMS. The samples were pre-treated in an autoclave with hydrogen peroxide to remove unwanted compounds from the urine samples and were acidified with nitric acid, followed by precipitation of iodine as silver iodide (AgI) for measurement by AMS. This new procedure is substantially faster than previous methods for the extraction of iodine from urine and results in less chemical waste. The efficiency and reproducibility of this method were evaluated by using 125I as a yield tracer, eventually giving a recovery above 99%. To achieve this, several iterations of the method were required. The method was then successfully applied to measure 129I/127I isotopic ratios and 129I concentrations in 25 human urine samples. The AMS results for 129I in urine ranged 3.3 x 106 atoms/L to 884 x 106 atoms/L and the isotope ratio (129I/127I) in human urine ranged from 7.38 x 10-12 to 3.97 x 10-10 with a median of 1.29 x ...
The long lived radioisotope (129)I is a uranium fission product, and an environmental contaminant... more The long lived radioisotope (129)I is a uranium fission product, and an environmental contaminant of the nuclear age. Consequently, it can trace anthropogenic releases of (129)I in watersheds, and has been identified as a potential means to distinguish water sources in discharge (Nimz, 1998). The purpose of this work was to identify the sources and mass input of (129)I and trace the transport, partitioning and mass balance of (129)I over time in a remote watershed. We monitored (129)I and other geochemical and isotope tracers (e.g. δ(14)CDIC, δ(13)CDIC, δ(2)H, δ(18)O, etc.) in precipitation and discharge from the Wolf Creek Research Basin (WCRB), a discontinuous permafrost watershed in the Yukon Territory, Canada, and evaluated the use of (129)I as a water end-member tracer. Radiocarbon and geochemical tracers of weathering show that discharge is comprised of (i) groundwater baseflow that has recharged under open system conditions, (ii) spring freshet meltwater that has derived solu...
A new method was developed to extract 129I from urine samples and then measure it by AMS. The sam... more A new method was developed to extract 129I from urine samples and then measure it by AMS. The samples were pre-treated in an autoclave with hydrogen peroxide to remove unwanted compounds from the urine samples and were acidified with nitric acid, followed by precipitation of iodine as silver iodide (AgI) for measurement by AMS. This new procedure is substantially faster than previous methods for the extraction of iodine from urine and results in less chemical waste. The efficiency and reproducibility of this method were evaluated by using 125I as a yield tracer, eventually giving a recovery above 99%. To achieve this, several iterations of the method were required. The method was then successfully applied to measure 129I/127I isotopic ratios and 129I concentrations in 25 human urine samples. The AMS results for 129I in urine ranged 3.3 x 106 atoms/L to 884 x 106 atoms/L and the isotope ratio (129I/127I) in human urine ranged from 7.38 x 10-12 to 3.97 x 10-10 with a median of 1.29 x ...
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Papers by Matthew N Herod