Advances in Sample Preparation for Semivolatile Analysis per EPA Method 625

Oral Presentation

Prepared by C. Marvin, D. Lucas, A. Riemann
Agilent Technologies, Inc., 2850 Centerville Road, Wilmington, DE, 19808, United States


Contact Information: [email protected]; 302-636-8423


ABSTRACT

The US EPA prescribes method 625 for the analysis of semivolatiles in waste water by GC/MS. Traditionally in this method, liquid-liquid extraction has been used to extract the large number of target analytes present in water samples requiring the use of large volumes of hazardous solvents and labor intensive mixing in separatory funnels that can result in emulsion formation. As sample preparation technologies advance, many of these drawbacks have been overcome; however, new technologies must meet performance criteria that demonstrate suitability for the method. This work will describe the use of solid phase extraction (SPE) as a suitable alternative to liquid-liquid extraction for EPA method 625. Target analytes are retained on a sorbent bed allowing elution with small volumes of organic solvent which minimizes solvent use and waste, eliminating large volume evaporation steps, increasing laboratory throughput, and avoiding problems such as emulsions. Data will be presented that demonstrates the advantages of SPE in challenging samples that meet the performance criteria as described in EPA method 625.