Evaluation of two adsorbents for diffusive sampling and thermal desorption-gas chromatographic analysis of monoterpenes in air

Abstract

Tube type samplers with two different adsorbents, Chromosorb 106 and Tenax TA, were evaluated by laboratory experiments and field tests for simultaneous diffusive sampling of alpha-pinene, beta-pinene and delta 3-carene and subsequent thermal desorption-gas chromatographic analysis. No statistically significant effects of exposure time, concentrations of monoterpenes or relative humidity were found for samplers with Chromosorb 106 when running a factorial design, with the exception of the adsorption of delta 3-carene, for which some weak effects were noted. Samplers with Tenax TA were affected by the sampling time as well as the concentration for all terpenes, with a strong interaction effect between these two factors. The terpenes showed good storage stability on both adsorbents. No effect of back-diffusion was noted when using Chromosorb 106, while Tenax TA showed some back-diffusion effects. The uptake rates, in ml min-1, for the terpenes on Chromosorb 106 were 0.36 for alpha-pinene, 0.36 for beta-pinene and 0.40 for delta 3-carene. The corresponding average values on Tenax TA were 0.30 for alpha-pinene, 0.32 for beta-pinene and 0.38 for delta 3-carene. The field validation proved that diffusive sampling on Chromosorb 106 agreed well with pumped sampling on charcoal for stationary samples, while the personal samples indicated a discrepancy of 25% between Chromosorb 106 and charcoal samples. Tenax TA generally gave lower results than Chromosorb 106 in all field samples. Samplers packed with Chromosorb 106 could be used to monitor terpene levels in workplaces such as sawmills. The major advantages with this method are the sampling procedure, which is simple to perform compared to other techniques, the easily automated analysis procedure and the possibility to reuse the samplers.

Development and validation by accuracy profile of a method for the analysis of monoterpenes in indoor air by active sampling and thermal desorption-gas chromatography-mass spectrometry

“…The present results showed that Tenax TA was a suitable sorbent for TD-GC-MS analysis of monoterpene hydrocarbons, and thus corroborated previous studies [52][53][54]. In contrast with the findings of Coeur et al [55], the present results revealed neither a time nor a temperature effect on the storage of the investigated molecules.…”

Isoprene and monoterpene fluxes measured above Amazonian rainforest and their dependence on light and temperature

“…In addition, the sample storage time was low (1-2 days) with demonstrated stability of monoterpenes on Tenax-TA over this time frame [Sunesson et al, 1999]. While ozone was not removed from the ambient air samples, low volumes of ambient air were collected (1.0 L) and its atmospheric mixing ratios were < 10 ppb on the majority of measurement days.…”

Multivariate evaluation of VOCs in buildings where people with non-specific building-related symptoms perceive health problems and in buildings where they do not

“…Carbopack X was used for sampling and analysis of 1,3-butadiene and benzene (Strandberg et al, 2005;Sunesson et al, 2006). The tubes were thermally desorbed in an ATD 400 (Perkin Elmer) connected to a gas chromatography-mass spectrometry (GC-MS) system (Hewlett Packard/Agilent 5973/6890, Stockholm, Sweden).…”