AWWA WQTC69296

Research is now complete on the U.S. Environmental Protection Agency's (USEPA's) effort to revise USEPA Method 524.2 for volatile organic contaminants in drinking water. The new method, Draft Method 524.3, achieves several significant goals. It has a revised list of analytes that now includes the iodinated trihalomethanes (I-THMs), fuel oxygenates, and volatile organic compounds (VOCs) amenable to purge-and-trap from the preliminary Contaminant Candidate List 3 (CCL3). It employs maleic acid, a common food preservative, to preserve samples, eliminating the requirement to ship a hazardous reagent (hydrochloric acid) to the field. The new method also allows selected ion monitoring (SIM) for the detection of analytes with very low regulatory limits. Three purge-and-trap concentrators and several traps were evaluated under a large range of purge volumes, purge rates, and dry purge times to determine acceptable limits for these parameters in order to allow method flexibility without jeopardizing performance. Validation studies in a single laboratory have been completed to validate the revised method for precision, accuracy, detection limit, and storage stability using the new preservation agents. Includes 2 references, tables.