Quantitative Assessment of Bromide Ion Measurements in NTN Samples by Ion Chromatography
Lee Green and Tracy Dombek
Central Analytical Laboratory (CAL)
National Atmospheric Deposition Program
Illinois State Water Survey
Champaign, IL 61820
Bromide is released into the environment via natural and anthropogenic processes. Brominated compounds are used in the production of polymers to increase the fire resistance of a wide variety of products. Methyl bromide is used as a fumigant for a variety of fruits and vegetables and can be applied to soils before plant growth. It can be applied post harvest for some food processing applications. Methyl bromide is classified as an ozone-depleting substance and its use is strictly regulated and monitored by the U.S EPA.
Ethylene dibromide (EDB) was also used as a fumigant until 1984 when it was banned for soil and grain use by the EPA because of its extreme toxicity to human health. Ethylene dibromide is currently used in the treatment of felled logs for bark beetles and termites, and control of wax moths in beehives. EDB can migrate to groundwater supplies, leading to human health concerns (http://www.epa.gov/OGWDW/contaminants/dw_contamfs/ethylene.html). The Central Analytical Laboratory (CAL) for the National Atmospheric Deposition Program/National Trends Network (NADP/CAL) measures chloride, nitrate, and sulfate by Ion Chromatography (IC) The CAL has investigated the analysis of bromide as an anion measurement by IC in NADP/NTN samples.
The estimated MDL 0.006 ppm was determined by measuring the CAL’s lowest calibration standard. As part of bromide ion method development, the CAL measured bromide concentrations in weekly supply blank samples (NADP collection buckets, lids, buckets, bags, etc.) The results from these samples were used to determine background levels of bromide present in the CAL’s supplies. The CAL measured bromide in all of the NADP/NTN samples processed throughout summer and will highlight samples or areas that test positive for bromide