Soluble phthalocyanines as coatings for quartz-microbalances: specific andunspecific sorption of volatile organic compounds

Various new phthalocyanines (PcMs) species were synthesized which can be di ssolved in organic solvents. They turned out to form particularly sensitive coatings on quartz-microbalances (QMBs) for the detection of a variety of volatile organic compounds (VOCs) in the gas phase. A two-step sorption mod el describes both, the initial highly sensitive response at low concentrati ons by preferential absorption and the less sensitive response at high conc entrations by non-preferential absorption for different analyte/PcM combina tions. The thermodynamic evaluation allows to determine the heats of specif ic interactions from temperature dependent sorption isotherms. (C) 1999 Els evier Science S.A. All rights reserved.