EPA 557 with Approved Modifications to EPA 557, Analysis of HAA by Ion Chromatography Mass Spectrometry with Faster Run Time for Regulatory Samples.

Oral Presentation

Prepared by A. Haghani, A. EATON
Eurofins Eaton Analytical, LLC, 750 ROYAL OAKS SUIT 100, MONROVIA, CA, 91016, United States


Contact Information: Alihaghani@Eurofinsus.com; 626-386-1138


ABSTRACT

EPA 557 with Approved modifications to EPA 557, analysis of HAA by Ion Chromatography Mass Spectrometry with faster run time for regulatory samples.
Ali Haghani, Andy Eaton
Eurofins Eaton Analytical, LLC1, 750 Royal Oaks Suit 100, Monrovia, CA, 91016

Haloethanoic (haloacetic) acids (HAAs) are formed as disinfection byproducts (DBPs) during the chlorination of natural water to make it fit for consumption. Drinking water contaminated with haloacetic acids may cause irritation to your eyes and skin and increase your risk of cancer. It is difficult to determine safe and toxic levels of haloacetic acid in water for human consumption because it is consumed in varying amounts over a long period of time. The amount of haloacetic acid in drinking water in the United States ranges from 0.0053 to 0.016 milligrams per liter. The Environmental Protection Agency standards for haloacetic acid in water are 0.06 milligrams per liter. Sundry analytical techniques have been applied in order to determine the concentrations of the HAAs in potable water supplies: gas chromatography (GC-MS, GC-ECD); capillary electrophoresis (CE); liquid chromatography (LC), including ion chromatography (IC)p and electrospray ionization mass spectrometry (ESI-MS). Detection limits required to analyze potable water samples can be regularly achieved only by GC-ECD and ESI-MS. Without improvements in preconcentration or detector sensitivity, CE and LC will not find application to potable water supplies. The predominant GC-ECD methods use either diazomethane or acidified methanol to esterify (methylate) the carboxylic acid moiety. For HAA5 analytes, regulated under the EPA's Stage 1 DBP Rule, diazomethane is satisfactory. For HAA9 data gathered under the Information Collection Rule, acidified methanol outperforms diazomethane, which suffers from photo-promoted side reactions, especially for the brominated trihaloacetic acids. Although ESI-MS can meet sensitivity and selectivity requirements, EPA 557 run time of >50 minute limits itís usage for commercial laboratories analyzing large quantity of HAA samples. This presentation demonstrates how to modify the run time to 30 minutes while meeting all of the strict EPA 557 requirements. This presentation will discuss the setup, Initial demonstration of capability and comparison of data gathered by EPA 557 for HAA9 to EPA 552.3 (GC-ECD) method used for UCMR4 samples.