title: Investigation to find a suitable reference material for use as an inverse gas chromatography system suitability test.
abstract: The purpose of this study was to find a suitable material for use as a system suitability test material for inverse gas chromatography (IGC). The purpose of a system check is to measure the variability of the instrument being used rather than the material being analysed. Having such a system check for IGC enables a basic GMP requirement to be met. IGC results can then be used in regulatory submissions to support other already established techniques for characterising pharmaceutical materials. Alpha-alumina was chosen because it is inorganic, stable at high temperatures, resistant to hydration and is already established as a system check material for surface area determination by nitrogen adsorption. Two columns (1 and 2) packed from the same reference sample jar of alpha-alumina and analysed under the same conditions yielded dispersive surface energies of 34.8+/-0.8 and 35.3+/-0.8 mJ/m(2), respectively, at 15% RH. Column 1 was analysed on a second IGC system, and gave a dispersive surface energy of 34.7+/-0.2 mJ/m(2). No significant change was evident after 7 months storage under laboratory ambient conditions. Analysis of material from a second reference sample jar of alpha-alumina produced results not noticeably different to those of the first, yielding a dispersive surface energy of 35.3+/-0.1 mJ/m(2). A change was seen to occur in the surface properties alpha-alumina when the humidity was varied, but the change appeared to be consistent across the two columns reported. Based upon the data in this experimental, alpha-alumina appears to be a suitable material for use as a system suitability test material for IGC.
authors.affiliation: GlaxoSmithKline, New Frontiers Science Park, Third Avenue, Harlow, Essex CM19 5AW, UK. joanne.2.stapley@gsk.com
authors.forename: J
authors.initials: J
authors.lastname: Stapley
authors.forename: G
authors.initials: G
authors.lastname: Buckton
authors.forename: D
authors.initials: D
authors.lastname: Merrifield
mesh_terms: D000537:Aluminum Oxide; D002626:Chemistry, Pharmaceutical / Q000295:instrumentation / Q000592:standards*; D002849:Chromatography, Gas / Q000295:instrumentation / Q000592:standards*; D005740:Gases; D006813:Humidity; D007202:Indicators and Reagents; D012015:Reference Standards
chemical_list: D005740:Gases; D007202:Indicators and Reagents; D000537:Aluminum Oxide