You are here:
SOLID-PHASE EXTRACTION OF 35 DBPS WITH ANALYSIS BY GC/ECD AND GC/MS
Citation:
CHINN, R., T. LEE, S. KRASNER, M. DALE, S. D. RICHARDSON, J. G. PRESSMAN, T. F. SPETH, R. J. MILTNER, AND J. E. SIMMONS. SOLID-PHASE EXTRACTION OF 35 DBPS WITH ANALYSIS BY GC/ECD AND GC/MS. In Proceedings, 2007 Water Quality Technology Conference, Charlotte, NC, November 04 - 08, 2007. American Water Works Association, Denver, CO, 1-20, (2007).
Impact/Purpose:
(1) Use a toxicity-based approach to prioritize and identify DBPs that show the greatest toxic response. (2) Comprehensively identify DBPs formed by different disinfectant regimes for the 'Four Lab Study'. (3) Determine the mechanisms of formation for potentially hazardous bromonitromethane DBPs.
Description:
An analytical method for 35 disinfection by-products (DBPs) was developed for a U.S. Environmental Protection Agency (EPA) health effects study. A toxicological evaluation was conducted on drinking water that was "scaled-up" using reverse osmosis (RO) by concentrating the total organic carbon (TOC) from a treated surface water by ~130-fold, replacing bromide lost in the concentration process, and subjecting the concentrate to chlorine disinfection scaled up by the increased TOC content. This concentrated water presented analytical challenges, which were resolved by merging two methods, providing excellent quality control data while increasing the efficiency of the analysis and offering confirmation data for 19 of the target analytes. An automated solid phase extraction procedure was used for all of the sample preparation and the liquid-liquid extraction (LLE) method was eliminated. The sample extract was divided into two separate volumes for analysis by two different instruments. The previously used LLE method offered better extraction recoveries; however other drawbacks of the LLE method resulted in the selection and use of the solid phase extraction method. Quality control data was compared between the two instrumental methods and were found to be similar. Disinfection by-product degradation was shown to occur in two ways: base-catalyzed hydrolysis in water and thermal loss during heated injections on the gas chromatograph. Analytical conditions were chosen to minimize these problems.