Exploring Lower-Level Analysis with DWRL 123-TCP Method: Insights into 123-TCP, EDB and DBCP EvaluationDrinking Water
Poster Presentation
Prepared by T. Nguyen, E. Chae, C. Carroll, L. Sanchez, P. Parmar
Orange County Water District, 18700 Ward St, Fountain Valley, CA, 92708, United States
Contact Information: [email protected]; 714-378-3378
ABSTRACT
Under Clean Water Act, the State Water Resources Control Board (SWRCB) has required that water agencies monitor and set the maximum contaminant level (MCL) for 1,2,3-trichloropropane at five parts-per-trillion (ppt). The Orange County Water District's Phillip L. Anthony Advanced Water Quality Assurance Laboratory uses an EST autosampler to transfer water samples into the sample loop and spiked with the isotope-labeled internal standard, d5-TCP. The purge and trap (PT) introduce the sample to the Agilent 8890 GC, coupled with a 5977C Single Quadrupole (SQ) Mass Spectrometer in selected ion monitoring mode (SIM) to lower the detection limits for 1,2,3- trichloropropane (123-TCP) to 2 ng/L based on the DWRL method Revision 2021.0.
In addition, the laboratory has expanded the scope of the method by adding two synthetic organic compounds (SOC), namely 1,2-Dibromoethane (EDB) and 1,2-Dibromo-3-chloropropane (DBCP) for monitoring. The reporting limits for 123-TCP, EDB, and DBCP are 2, 5 and 10 ng/L, respectively. To achieve the lower reporting limit a method modification was made by using a 20 mL sample loop along with refining the PT and GC-MS parameters. This comprehensive evaluation using the DWRL 123-TCP method shows its efficiency in achieving reliable low-level analysis for 123-TCP, EDB and DBCP, making it a valuable tool for environmental monitoring. The Method Detection Limit (MDL) for 123-TCP was 0.444 ng/L, and accuracy was 109.8% with an RSD of 6.4%.
