Perchlorate Quantitation by LC-MS/MS in Aqueous MatricesDrinking Water
Poster Presentation
Presented by D. Tran
Prepared by M. Brown1, C. Shields2, D. Tran2
1 - SCIEX, 250 Forest St, Marlborough, MA, 01752, United States
2 - SCIEX, 6390 Joyce Drive #100, Golden, CO, 80403, United States
Contact Information: [email protected]; 508-683-9241
ABSTRACT
Perchlorate is a highly soluble and persistent anion widely used as a strong oxidizer in industrial and commercial applications, including explosives, rocket propellants, fireworks, and electroplating of metal finishes. Its widespread use has resulted in environmental contamination and human exposure, raising significant public health concerns. Perchlorate interferes with iodide uptake in the thyroid gland, potentially disrupting thyroid hormone production and adversely affecting prenatal and postnatal development, metabolism, and adult cognitive function.
In response to these risks, several regulatory limits have been established for perchlorate in drinking water. California previously set a maximum contaminant level (MCL) of 6 μg/L (ppb) and has recently approved a revision to 2 μg/L, while Massachusetts has established an MCL of 2 μg/L. At the federal level, the U.S. Environmental Protection Agency (EPA) has proposed a maximum contaminant level goal (MCLG) of 20 μg/L under the Safe Drinking Water Act (SDWA). If adopted, routine compliance monitoring will rely on water utilities, necessitating sensitive, reliable, and accessible analytical methods.
Numerous liquid chromatography–tandem mass spectrometry (LC‑MS/MS) methods for perchlorate determination have been reported, most commonly employing ion‑exchange chromatography for analyte retention. While effective, these approaches often require specialized instrumentation and columns. This study presents a reverse‑phase LC‑MS/MS method designed to facilitate adoption by laboratories already equipped for conventional reverse‑phase analysis.
Chromatographic separation was achieved using a reverse‑phase column with a mobile phase consisting of 10 mM ammonium formate in water (mobile phase A) and acetonitrile (mobile phase B). Detection was performed using a triple quadrupole mass spectrometer operating in multiple reaction monitoring (MRM) mode. The method achieved a lower limit of quantitation below the proposed federal limit of 20 μg/L and met the 2 μg/L LOQ required by California and Massachusetts. Commercially available bottled water and residential tap water samples were analyzed, demonstrating the method’s suitability for routine perchlorate monitoring in drinking water.
