Improved EPA 625 Analysis Using Large-Particle Solid Phase Extraction

Oral Presentation

Prepared by T. Anderson, K. Parnell, M. Trass, A. Misa, S. Huq
Phenomenex, 411 Madrid Ave, Torrance, CA, 90501, United States


Contact Information: [email protected]; 310-212-0555


ABSTRACT

EPA Method 625 is used to test for a wide range of semi-volatile organic-pollutants in water. The method specifies liquid-liquid extraction (LLE) followed by GC/MS analysis. Though sufficient to achieve method requirements, LLE presents limitations on recovery, accuracy, and procedural efficiency. Attempts have been made to transfer the method from LLE to Solid Phase Extraction (SPE); in comparison to LLE, SPE has numerous benefits including faster extraction time, solvent reduction, increased reproducibility and increased recovery. However, when standard SPE methodology is applied to water samples containing particulates or sediment, the SPE cartridges often become clogged and extraction data becomes unreliable.

With increasing importance on productivity gains, successful implementation of the SPE technique has gained attention. Therefore, an improved SPE methodology has been developed that incorporates large-particle polymeric SPE cartridges (Strata-XL-C) and improvements in drying. The large-particle extraction-method is effective for the entire range of EPA 625 analytes and is considerably faster and more user-friendly than LLE or standard SPE protocols. Following SPE, the sample is analyzed using a Zebron GC column on a GC/MS system, resulting in a rapid 17 minute run time. By utilizing the large-particle SPE method and Zebron GC method outlined here, EPA Method 625 efficiency, reproducibility and productivity is dramatically improved.