Journal of Chromatography A, 1375 (2015) 140–145 Contents lists available at ScienceDirect Journal of Chromatography A jo ur nal ho me pag e: www.elsevier.com/locate/chroma A novel method for measuring trace amounts of total sulphur-containing compounds in hydrogen Michael L. Downey ∗ , Arul Murugan, Sam Bartlett, Andrew S. Brown Analytical Science Division, National Physical Laboratory, Teddington, Middlesex TW11 0LW, United Kingdom a r t i c l e i n f o Article history: Received 13 October 2014 Received in revised form 26 November 2014 Accepted 27 November 2014 Available online 4 December 2014 Keywords: Hydrogen Purity Quality Total sulfur Gas chromatography Trace analysis a b s t r a c t A novel method for the analysis of total sulphur-containing impurities in a hydrogen matrix has been developed. This method has a limit of detection (LoD) significantly lower than that maximum amount fraction for sulphur-containing compounds (4 nmol mol -1 ) specified by the international standard for hydrogen to be used in fuel cell vehicles (ISO 14687-2). To measure the LoD for this method, a novel gas standard containing five different sulphur-containing compounds at low nmol mol -1 amount fractions has been gravimetrically prepared. Stable primary gas standards that are traceable to the SI were used to successfully validate the amount fractions of the sulphur-containing compounds in this gas standards using gas chromatography with flame ionisation detection (GC-FID) and sulphur chemiluminescence detection (GC-SCD). © 2014 Elsevier B.V. All rights reserved. 1. Introduction As Governments set targets to reduce carbon dioxide emissions and increase the use of energy produced from renewable sources [1,2], several new energy infrastructures are becoming established. To realise these targets, powering vehicles using hydrogen is one possible route. Hydrogen is predicted to be a key future energy vector as it can be produced by a completely carbon free path at the point-of-use; one way being to use electrolysis powered by renewable energy sources [3]. Additionally, the use of proton exchange membrane (PEM) fuel cells in vehicles or other devices is a viable method for providing energy to these systems without releasing carbon dioxide or other pollutants into the urban environment. These qualities have led major automotive manufacturers to produce hydrogen fuel cell vehicles and several countries to establish hydro- gen refuelling networks: as of March 2013 there were 208 hydrogen re-fuelling stations worldwide with 95 more planned [4,5]. PEM fuel cells operate by facilitating the catalytic reaction of hydrogen with oxygen from the air across an electrolyte that is permeable only to hydrogen ions, thus producing an electric current. A significant potential drawback is that the catalyst (usu- ally platinum) used at the fuel cell cathode is very susceptible to ∗ Corresponding author. Tel.: +44 020 8943 6121; fax: +44 020 8614 0446. E-mail address: michael.downey@npl.co.uk (M.L. Downey). degradation by impurities. Therefore in order to ensure fuel cell lifetime, the hydrogen supplied to the device must meet stringent purity requirements. In order to address this issue, standards have been published that dictate the minimum quality of hydrogen that should be used in fuel cell vehicles. A recent ISO (International Organisation for Standardisation) standard (ISO 14687-2) [6] provides purity speci- fications for hydrogen to be used in PEM fuel cells (Table 1). The SAE (Society of Automotive Engineers) have used the same purity crite- ria in their own standard SAE J2719 [7]. Future legislation is likely to incorporate these specifications, as indicated by the proposed EC Directive [8] on the deployment of an alternative fuels infrastruc- ture which states, “hydrogen refuelling points shall comply with the relevant EN standard, to be adopted by 2014, and, pending pub- lication of this standard, with the technical specifications included in the ISO 14687-2:2012 standard.” This paper discusses the analysis of total sulphur-containing compounds in hydrogen with the aim of achieving a limit of detec- tion (LoD) lower than the maximum allowed amount fraction specified in ISO 14687-2 (4 nmol mol -1 ) (the standard also has an additional, non-mandatory recommendation than the LoD should ideally be three times lower than this). Sulphur-containing compounds can be present in hydrogen pro- duced by the steam reformation of natural gas [6]. The typical compounds found are likely to be those originally present in natu- ral gas such as thiols, organic sulphides and hydrogen sulphide. The analysis of such compounds in odorised natural gas is well http://dx.doi.org/10.1016/j.chroma.2014.11.076 0021-9673/© 2014 Elsevier B.V. All rights reserved.