Perchlorate is a known contaminant in both drinking water and groundwater, with natural and manufacturing sources. A strong oxidizer, perchlorate has been used in solid rocket fuels, airbags and fireworks. It was identified in low concentrations in the Chilean fertilizers, extensively used in the 19th century in the United States. Perchlorate has atmospheric sources, being reported previously in precipitations. As an anion, it is not expected to travel free for long distances in the atmosphere.

This study, designed to assess natural sources of perchlorate, considered collecting samples from a remote area, with no exposure to manufactured perchlorate. High Arctic ice caps receive contaminants solely from atmospheric sources, which allow determining the annual flux of perchlorate received through precipitation. Depth samples, dating between 1996 and 2005, were collected from Devon Island, Nunavut, Canada, in the spring of 2006. A direct injection, optimized ion chromatography-tandem mass spectrometry (IC-MSMS) method allowed detection of perchlorate in all samples. Concentrations were in low ng/L range and showed seasonality. This represents the first temporal trend reported for perchlorate in precipitation. The same samples were previously analyzed for perfluorinated acids, evidencing their atmospheric formation [1].

[1]. CI Young, VI Furdui, J Franklin, RM Koerner, DCG Muir, SA Mabury Perfluorinated Acids in Arctic Snow: New Evidence for Atmospheric Formation, 2007, Environ Sci Technol, 41, 3455-3461.