Saturday, December 22, 2012

Monitoring ppb levels of ambient air pollutants via hyphenated techniques: HRGC/ in-series selective detection


Accepted for presentation in Advancements in Air Monitoring Symposium at the Spring National Meeting of the American Chemical Society April 2013

AUTHORS

1. Jack N Driscoll1 , Dr., PID Analyzers, LLC, 2 Washington Circle, #4, Sandwich, MA, 02563, United States , 6176994307, United States 
2. Jennifer L Maclachlan1 , PID Analyzers, LLC, 2 Washington Circle, #4, Sandwich, MA, 02563, United States , 6176994307, United States



Title: Monitoring ppb levels of ambient air pollutants via hyphenated techniques: HRGC/ in-series selective detection
Abstract Body: High resolution gas chromatography (HRGC) with a capillary column (50,000 to 100,000 theoretical plates) is an efficient and effective means for separation of a complex mixture of chemicals in the ambient air. Since retention times are used for identification, either a second column with a different polarity or the ratio of two detectors are used to confirm the identity of various solutes in a number of USEPA methods. The photoionization detector [1] is a very sensitive (0.5 ppt benzene (VOC's) and non-destructive detector (second detector can be run in-series) for volatile and semivolatile organic compounds. The PID/FID method was described more than 30 years ago [2] for identification of natural gas components, and has been used more recently for identification of ambient hydrocarbons. In a similar manner, a flame photometric detector (FPD) can be used in conjunction with the PID to identify S or P compounds in the air. A PID Analyzers Model 322 Automatic GC with temperature programming and a PID/FID or a PID/FPD was used for these measurements. The ambient measurements were made near our Cape Cod, MA facility which is at the perimeter of the Mass Military Reservation.
References
1. Driscoll, J.N., “Gas Chromatography in Environmental Analysis” Environmental Instrumentation Handbook, Wiley , NY (2005)
2. Driscoll, et al., "Gas Chromatographic Detection and Identification of Aromatic and Aliphatic Hydrocarbons in Complex Mixtures by Coupling Photoionization and Flame Ionization Detectors," J. Chrom., 158, 171 (1978).

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