ARS | Publication request: PERCHLORATE IS NOT A COMMON CONTAMINANT OF FERTILIZERS

Submitted to: Journal of Agronomy and Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 2, 2001
Publication Date: March 4, 2002
Citation: Hunter, W.J. 2002. Perchlorate is not a common contaminant of fertilizers. Journal of Agronomy and Crop Science. 187(3): 203-206.

Interpretive Summary: A recent publication suggested that perchlorate was a common contaminant of fertilizers and concluded that fertilizers may be a source of perchlorate contamination of soils and waters. The present study demonstrated that perchlorate was not a contaminant in any of the 15 fertilizers surveyed. These data suggest that perchlorate is not a common contaminant of US fertilizers.

Technical Abstract: Perchlorate consumption can cause mental retardation and tumor formation in humans. Recent suggestions that perchlorate may be present as a contaminant in fertilizers and fertilizer components caused concern within the fertilizer industry. The present study developed methods for improving the HPLC analysis of perchlorate and used these methods to survey 15 US fertilizers for perchlorate. Extraction with 50 mM NaOH rather than water was found to improve extraction efficiency from 84% to 98%. The incorporation of Ca(HO)2 into the extraction medium to yield 1:0.5 or 1:1, SO4-:Ca+2 molar ratios reduced the analytical interference caused by SO4-2 by reducing the slope of the SO4-2 peak tail by ~ 75%. The study found no perchlorate in any of the fertilizers investigated.