Performance and characteristics of a trace gas analyzer for the determination of volatile organic compounds in air

Abstract

Adsorptive enrichmenthhermal desorption Micro t r a p VOC and PVOC analysis Humid air sample analysis. SummaryAn instrument has been developed and tested for the continuous measurement of volatile organic compounds (VOC) in air. The system consists of a gas chromatograph equipped with a dedicated sampling device that allows the sample to be transferred to a cooled microtrap via sampling loops (10,100,250 ml) or via a direct pump transfer to the trap. The microtrap is placed in the chromatographic oven just below a modified split-splitless injector, allowing direct liquid injection for calibration of the system; the injector is in communication with the sampling valve equipped with the loop and the sampling pump. The system allows 24-hour sampling and analysis of a large number of VOC (up to 25 individual hydrocarbons ranging from C2-C9) and also polar volatile organic compounds PVOC. Thanks to the particular trap geometry, a minimum consumption of liquid nitrogen (between 150-300 ml) is needed for each analytical run and no water managing system is normally required for humid air samples.

Enhanced preconcentration of selected chlorofluorocarbons on multiwalled carbon nanotubes with polar functionalities

“…Generally, a preconcentration step is necessary to improve sensitivity and detection limits in trace‐level determination. Microsorbent traps, referred to as a microtrap, have been developed to serve as integrated concentration–injection devices for continuous trace level monitoring . Their small dimensions allow rapid desorption of adsorbed compounds with the potential advantages of faster operation, narrow peak width, and sub‐ppb detection limit.…”

Comparison of Partial Reactive Organic Gases (ROG) Emission Factors from a Dairy and Beef Feedlot

“…Not all identified VOC are ROG, some are non-reactive hydrocarbons which may not significantly contribute to ozone formation. According to Monari et al (1996) most of the measured individual VOC are expressed as the sum of non-methane hydrocarbons, and these measurements do not give information on the photochemical reactivity of the hydrocarbon mixtures.…”