Quantification of CO2, SO2, NH3, and H2S with a single coated piezoelectric quartz crystal

Previous experiments showed that a quartz crystal coated with tetramethylammonium fluoride tetrahydrate (TMAF) could be used to quantify CO2. It was also known that TMAF absorbed SO2 and H2S, although there were no studies involving quartz crystal microbalances (QCMs) with the latter gas. The remarkable stability of the frequency of the TMAF-coated crystals was reason enough to test them for a series of gases of environmental interest: CO2, SO2, NH3, H2S, and CO. Studies of Sensitivity of TMAF to those gases are reported, along with a detailed discussion of the signal shape. Traps of specially prepared molecular sieves were used in an attempt to separate some of the analytes. (C) 2000 Elsevier Science S.A. All rights reserved.