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Binary Mixtures of Permanganate and Chlorinated Volatile Organic Compounds in Groundwater Samples: Sample Preservation and Analysis
Citation:
Johnson, K. T., M. WICKHAM-ST. GERMAIN, S. Ko, AND S. G. HULING. Binary Mixtures of Permanganate and Chlorinated Volatile Organic Compounds in Groundwater Samples: Sample Preservation and Analysis. GROUNDWATER MONITORING AND REMEDIATION. National Ground Water Association, Westerville, OH, 32(3):84-92, (2012).
Impact/Purpose:
Journal article for Ground Water Monitoring and Remediation
Description:
Ground water samples collected at sites where in-situ chemical oxidation (ISCO) has been deployed may contain binary mixtures of ground water contaminants and permanganate (MnO4-), an oxidant injected into the subsurface to destroy the contaminant. Commingling of the oxidant and contaminant in aqueous samples may negatively impact the quality of the sample and the analytical instruments used to quantify contaminant concentrations. Ascorbic acid was used to preserve binary mixtures involving a multi-component standard and permanganate and further evaluated involving ground water samples collected at two ISCO field sites. Ascorbic acid reacts rapidly with the MnO4- and limits the reaction between MnO4- and the organic compounds in the mixture. Consequently, the concentrations of many of the compounds in the multi-component standard were within the control limit for quality assurance. However, despite timely efforts to preserve the samples, concentrations in the binary mixture were time-dependent and the concentration of several sensitive compounds fell significantly below the lower control limit. Concentrations of VOCs in field-preserved binary mixture ground water samples were greater than in samples refrigerated in the field, and preserved upon arrival at the lab indicating the time-dependency and benefit of field preservation.
