A Cleaner, More Sensitive Approach to EPA Method 8260 Using Large Volume Static Headspace and Active SPME Preconcentration Prior to GCMS Analysis

ABSTRACT

An improved approach for performing EPA method 8260 is presented. Large Volume Static Headspace (LVSH) sample introduction is used which improves method sensitivity relative to standard Purge & Trap technology while maintaining a cleaner system, resulting in longer operation without servicing. A 20mL sample volume is prepared in 40mL VOA vials along with 10g NaCl to help transfer VOCs to the headspace. After automated heating and mixing, 10cc of headspace is introduced into a 3-stage preconcentrator that extracts the SVOCs, water vapor and VOCs in three different traps, followed by backushing of the Tenax^® trap to the first trap for dynamic focusing prior to injection. Refocusing of the sample allows a splitless injection to be made into the GCMS, greatly improving sensitivity. Elimination of sample purging reduces foam and/or aerosol formation, keeping transfer lines clean for an extended period of time. Dean’s Switch technology is used to control ows throughout the system, eliminating problematic rotary valves that increase system carryover and are often the points where leaks occur most frequently. A unique volume measurement technique provides a very consistent approach for volume measurement, insuring excellent overall analytical reproducibility. Data is presented showing 8260 method compliance in regards to calibration linearity, method detection limits, and reproducibility.

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• Create Date November 14, 2018
• Last Updated February 15, 2023