Validation of a Novel Bioassay for Low-level Perchlorate Determination
Abstract
The bioassay for low-level perchlorate (Perchlorate)determination (range approximately 6 to 40 micrograms per liter [ g/L]), which was the focus of the project, is a benchtop enzyme assay combined with a perchlorate concentration and purification step using solid phase extraction (SPE) cartridges (Heinnickel et al., 2011). It is based on perchlorate reductase activity and couples reduced nicotinamide adenine dinucleotide (NADH) oxidation to perchlorate reduction, with phenazine methosulfate (PMS) as an electron shuttle. Hence the amount of perchlorate in an aqueous sample can be determined enzymatically by monitoring the amount of NADH oxidized spectrophotometrically (i.e., by measuring the decrease in absorbance at 340 nanometer [nm]). The instrumentation for the bioassay is a ultraviolet (UV) spectrophotometer. The equipment and materials are relatively inexpensive and the bioassay potentially may be performed by less highly trained personnel than required by ion chromatography (IC) or liquid chromatography/mass spectrometry (LC/MS) analytical methods. Thus it was thought likely that the benchtop bioassay might supplement more expensive and time consuming analytical procedures as a screening test for perchlorate in groundwater to facilitate tasks such as mapping plumes and monitoring perchlorate levels during remediation. The three performance objectives of the project were: (1) Compare benchtop bioassay results from testing in the principal investigator s (PI) laboratory to results from a reference analytical method performed by a commercial laboratory; (2) Compare results with a benchtop bioassay kit format tested by site field personnel to the site s routine perchlorate detection method; and (3) Evaluate the ease of use of the benchtop bioassay kit format. Six groundwater sources were obtained for the project. Success criteria were met for one of groundwater sources, but were not met for four other groundwater sources.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2013
- Accession Number
- ADA619824
Entities
People
- John D. Coates
Organizations
- University of California, Berkeley