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PERCHLORATE IN FERTILIZERS?: ANALYSIS BY RAMAN SPECTROSCOPY
Citation:
Collette, T W. AND T. L. Williams. PERCHLORATE IN FERTILIZERS?: ANALYSIS BY RAMAN SPECTROSCOPY. Presented at 220th American Chemical Society National Meeting, Washington, DC, August 20-24, 2000.
Impact/Purpose:
Elucidate and model the underlying processes (physical, chemical, enzymatic, biological, and geochemical) that describe the species-specific transformation and transport of organic contaminants and nutrients in environmental and biological systems. Develop and integrate chemical behavior parameterization models (e.g., SPARC), chemical-process models, and ecosystem-characterization models into reactive-transport models.
Description:
Recently, we and others found perchlorate at high levels (approximately 500 - 8000 mg/kg) in 90+% of 25+ fertilizers (primarily lawn-and-garden products) that are not identified as containing components derived from mined Chile saltpeter, which is known to contain perchlorate as a natural contaminant. These products were acquired over the period of November 1998 to January 1999 at 5 locations across the U.S. However, we have subsequently analyzed 20+ similar products, which were acquired after July 1999. Some of these were the same products (although not the same lots) as those previously sampled. Most of these new products do not contain perchlorate above the ion chromatographic detection level. While our more recent results suggest that the contamination of the earlier products may have been an episodic (if not singular) event, there is an ongoing need for robust analytical methods for rapid and definitive analysis of perchlorate in complex matrices such as fertilizer extracts. We will focus the majority of this talk on the merits of Raman spectroscopy to meet this need.