Fast GC Analysis with PID and FUV Detectors for Industrial Hygiene Monitoring at Low ppb Levels by John N. Driscoll, D. Walsh of PID Analyzers and Phil Smith of USDOL OSHA, has been accepted for podium presentation during the 2011 American Industrial Hygiene Conference & Expo (AIHce), May 14-May 19 in Portland, OR.
Topic:Air Sampling Instrument Performance
Presentation #:PO 111-1
This podium presentation is scheduled in the session titled Field Detection, Sampling and Analysis: Real Time Detection Systems, scheduled for Tuesday May 17, 2011 10:30 AM - 10-50 AM.
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Objective: Fast Analysis of Gases and Solvents- Industrial Hygienists are typically pushed to provide rapid solutions involving a variety of complex mixtures that threaten workers health.
Methods: Portable Gas chromatography with a photoionization detector (PID),one of the most sensitive detectors for organic compounds, and a Far UV detector (nearly universal detector with ppb detection capability). The detection limits for benzene with these two detectors on a conventional capillary column (0. 32 mm id X 15M wax with an 0.5 μ film) were 0.5 ppb for the PID and 30 ppb for the FUV.
Results-Our approach involves using a 25m x 0.32 mm packed with Haysep P (for analysis of solvents) that is restively heated and can be programmed at a high rate. It can also be cooled faster since it has a very small thermal mass. A sample of 50 ppb of benzene was run on the PID & FUV. Note that the peak heights (counts) were improved by 5-9 times for these two detectors. The analysis times were similar because of the stronger retention of benzene on the porous polymer column. The advantage here is that the porous polymer column can be used for gases or solvents whereas the capillary column is designed only for solvents.
Conclusions- The precision (coefficient of variation) at 50 ppb was +/- 5% for the PID and +/- 15% for the FUV. No significant difference in precision was observed between the two types of columns. The main advantage was that the fast GC (with porous polymer column) could analyze a much wider range of compounds than the capillary column.