Gas-chromatographic determination of concentrations of trace amounts of 46 odorants prepared in air in a 10-m3 stainless-steel odour test room

Abstract

The determination of the concentrations of trace amounts of 46 odorants prepared at odour threshold levels (in parts per billion) in air in a 10-m³ stainless-steel odour test room was investigated by gas chromatography using two pre-concentration methods, namely cold trapping with liquid oxygen and room-temperature adsorption trapping with porous polymer beads, such as Tenax-GC or graphitised carbon black coated with a small amount of stationary phase (SP-1000 + orthophosphoric acid)(0.3 + 0.3% on Carbopack B, 60–80 mesh). The 46 odorants tested were four sulphur compounds, ten lower aliphatic carbonyl compounds, an aromatic hydrocarbon, seven lower aliphatic mono-alcohols, eleven phenols, six lower aliphatic carboxylic acids and seven indoles. The recoveries of the odorants having boiling-points of less than about 150 °C were quantitative, but those having boiling-points of more than 160 °C gave recoveries of about 50%, except for the phenols, which had much lower recovery levels.