Comparison of some porous polymers as adsorbents for collection of odour samples and the application of the technique to an environmental malodour

Abstract

A range of Chromosorbs and Tenax-GC have been compared with regard to their efficiency as adsorbents for volatile odorous compounds using a very simple model system. When desorption was accomplished by solvent elution using acetone, Chromosorb 103 provided the best recoveries of those investigated (between 90 and 95%). I n situations where thermal lability of trapped compounds is not a problem, use of Tenax-GC and thermal desorption a t about 250 "C would be recommended on the basis of this survey, during which this approach consistently provided recoveries greater than 96% from small sample volumes. The latter procedure was applied to the analysis of an industrial malodour from an animal rendering factory, and using gas chromatographymass spectrometry over 35 compounds (92% of the total odour sample) were positively identified. I n particular, a range of alkylthiophenes may be characteristic of this particular odour.

Quantitative Performance of a Simple Tenax‐GC Adsorption Method For Use in the Analysis of Aroma Volatiles

“…For the 500 mL/min purged samples, substantial collections of the intermediate and higher molecular weight compounds were achieved after 7 min, and very good collections occurred after 30 min. However, continued purging at 500 mL/min through 180 min (3 hr) caused greatly diminished recoveries (<20%), and this was attributed to breakthrough or elution of the components from the Tenax-CC during collection by the high gas flow (Kuo et al, 1977;Bertsch et al, 1975;Krost et al, 1982). Similar effects probably account for much of the lack of sensitivity of the dynamicpurge system for the more polar short-chain alcohols in the mixture (Sakodynskii et al, 1974;Schaefer, 1981;Leahy and Reineccius, 1984).…”

“…Similar effects probably account for much of the lack of sensitivity of the dynamicpurge system for the more polar short-chain alcohols in the mixture (Sakodynskii et al, 1974;Schaefer, 1981;Leahy and Reineccius, 1984). High flow rates with the dynamic-purge system, however, have been advocated for lessening analysis times (Barnes et al, 1981), and the results of these trials indicate that such approaches are valid providing overall analytical conditions are appropriately established.…”

“…Tenax-GC (2,6-diphenylparaphenylene oxide polymer; ENKA, The Netherlands) has emerged as a widely-used porous polymer for these applications. Some of the general properties of adsorptive techniques in these applications have been reported, including retention volumes for different components (Kuo et al, 1977;Novotny et al, 1974;Sakodynskii, 1974;Bertsch et al, 1975;Krost et al, 1982;Kawata et al, 1982) and the effects of sampling times and purging rates on retention of volatiles on Tenax-GC (Buckholz et al, 1980). Other studies have involved assessments of recoveries of various components from porous polymers (Leahy and Reineccius, 1984;Williams, 1982) as well as reproducibility of analyses (Noble et al, 1980;Jennings et al, 1972;Withycombe and Lindsay, 1972).…”

Advantages and limits of adsorption sampling for physico-chemical measurements of odorous compounds

“…This last technique is convenient for evaluating present organic molecules and their concentration [2]. For many applications, it has become the standard method for the determination of target compounds in atmosphere [3][4][5][6].…”

“…This last technique is convenient for evaluating present organic molecules and their concentration [2]. For many applications, it has become the standard method for the determination of target compounds in atmosphere [3][4][5][6].Difficulties in the overall analysis of malodorous atmospheres arise from the different properties of their components, such as volatility, polarity and reactivity. None of commercial sorbents can be considered universal, i.e.…”