Journal of Chromatography A, 917 (2001) 367–374 www.elsevier.com / locate / chroma Short communication Investigation of the storage stability of selected volatile sulfur compounds in different sampling containers * Michael Sulyok, Christina Haberhauer-Troyer, Erwin Rosenberg , Manfred Grasserbauer Institute of Analytical Chemistry, Vienna University of Technology, Getreidemarkt 9 /151, A-1060 Vienna, Austria Received 31 July 2000; received in revised form 13 February 2001; accepted 13 February 2001 Abstract The suitability of various sample containers (i.e. standard Tedlar sample bags, black / clear layered Tedlar sample bags and Silcosteel sample cylinders) was examined for a gaseous multicomponent standard containing methylmercaptan, ethylmer- captan, dimethyl sulfide, ethylmethyl sulfide, 2-propylmercaptan, 1-propylmercaptan, 2-butylmercaptan, diethyl sulfide and 3 1-butylmercaptan (1 mg / m each in nitrogen). In the black/clear layered Tedlar sample bags, significant losses (up to 10% for methylmercaptan as the most critical component) were observed after 2 days, whereas in the standard Tedlar sample bags the recovery of methylmercaptan was approximately 90% even after 1 week. The Silcosteel sample cylinders were suitable for sampling of volatile sulfur compounds with respect to the stability of the analytes, but the recoveries exceeded 100% especially for the higher boiling compounds, which was attributed to enrichment effects on parts of the sampling system.  2001 Elsevier Science B.V. All rights reserved. Keywords: Volatile organic compounds; Sulfur compounds 1. Introduction warning agents for the consumer for safety purposes [1]. The odorisation process requires a fast and Knowledge of the type and concentration of accurate analytical method for the control of the volatile sulfur compounds (VSCs) in natural gas is of concentrations of the sulfur compounds in the raw great importance to the industry for several reasons. gas and of the odorant level in the odorized gas, On the one hand, these compounds poison catalysts, since excessive concentrations of these compounds cause corrosion and contribute to environmental result in an elevated number of consumer complaints pollution (formation of acidic rain), which makes the [2]. reduction of natural occurring VSC concentration The analysis of VSCs is particularly difficult, mandatory. On the other hand, odorous sulfur com- since they tend to adsorb onto surfaces and, in the pounds are added to the odorless natural gas as case of mercaptans, may undergo partial oxidation [3,4]. Therefore, all the materials which the VSCs come into contact with during sampling and analysis *Corresponding author. Tel.: 143-1-58801-15190; fax: 143-1- should be as inert as possible. In contrast to air 58801-15199. samples, where the concentrations of the VSCs are in E-mail address: erosen@mail.zserv.tuwien.ac.at (E. Rosen- 3 3 berg). the lower mg/m – or even in the ng/m – range 0021-9673 / 01 / $ – see front matter  2001 Elsevier Science B.V. All rights reserved. PII: S0021-9673(01)00654-9