Scaling Liquid-Liquid Sample Preparation: Moving from Separatory Funnels to a Vial-Based Extraction for Semivolatile Organics Analysis by GC-MS/MS

New Organic Monitoring Techniques
Oral Presentation

Presented by K. Rosnack
Prepared by F. Dorman, S. Dowd, D. Stevens
Waters, 34 Maple St, Milford, MA, 01757, United States


Contact Information: [email protected]; 508-282-9589

ABSTRACT

Historically, liquid-liquid extractions for aqueous samples has been a mainstay of environmental analytical chemistry. Using methodology such as USEPA Method 3510, or 3520 with automated continuous liquid-liquid extraction devices, tends to dominate the commercial world as these methods provide for well documented performance. Additionally, these methods yield a concentration factor (ca 500-1000) that has been critical in the meeting of required reporting limits for various determinative methods using gas chromatographic separation. While these methods are heavily employed, they do come with significant demands on human resources, time and reagent consumption. Lastly the use of laboratory glassware places demands on washing, revalidation, and it brings the potential for breakage and contamination through reuse.

This presentation will address the scaling of the common liquid-liquid extraction for semivolatile organics (USEPA 8270) using disposable labware. Additionally, this presentation will demonstrate that reporting limits are maintained with this vial-based extraction when moving from GC-MS to GC-MS/MS, so that client data remains unaffected by the switch in sample preparation technique. This is accomplished using a 20-mL extraction of aqueous sample and does not require a concentration step to reduce extract volume. Automation opportunities and batch-based processing will be discussed potentially allowing for a significant reduction in fixed costs and human resource demands in the environmental sample preparation laboratory.