Analytical support of environmental programs has been conducted for several decades using standard-bore capillary columns (0.25mmid) and quadrupole GCMS systems. Depending on method conditions and program requirements, the QC measures can consume a significant portion of a 12-hour shift, leaving less time for analysis of real-world samples. Typical cycle times (time from beginning of a run to the beginning of the following run) for EPA 8270D (and preceding semivolatile methods) have historically been on the order of 35-45 minutes, or longer.
The goal of this study was to demonstrate the capabilities of a new, sensitive, fast-scanning GCMS system to optimize productivity for EPA Method 8270D, while maintaining the strict QC measures of the method, optimizing sensitivity, and expanding the dynamic range.
Significant reduction in the run time can be accomplished by applying the Fast GC technique to this method. This technique involves the use of narrow bore (0.15mm ID) columns, rapid oven heating and cooling, and rapid data acquisition. Several considerations are necessary for reliable analysis using narrow-bore columns. A sensitive quadrupole mass spectrometer is required for identification and quantitation of target compounds at sub-nanogram levels. In addition, fast mass spectral scanning and data acquisition are required, because very narrow chromatographic peaks are produced under these conditions.
A new, sensitive, fast-scanning quadrupole GCMS system was used to significantly reduce the run time for a mixture of 81 analytes. Excellent sensitivity and chromatographic resolution were demonstrated with a significantly reduced run/cycle time.