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An atmospheric pressure chemical ionization mass spectrometer (APCI-MS) combined with a chromatographic technique to measure the adsorption enthalpy of acetone on ice

2003; Elsevier BV; Volume: 226; Issue: 2 Linguagem: Inglês

10.1016/s1387-3806(03)00019-8

1873-2798

Christophe Guimbaud, Thorsten Bartels‐Rausch, Markus Ammann,

Advanced Chemical Sensor Technologies

An atmospheric pressure chemical ionization mass spectrometer (APCI-MS) has been developed to investigate the adsorption properties of atmospheric trace gases on ice using a chromatographic method. The APCI-MS system is presented and discussed as an analytical technique to monitor the gas-phase concentration of trace species by proton transfer reaction and ligand switching reactions involving protonated water clusters as reagent ions. The chromatographic method used relies on temperature-dependent retention time measurements of trace gases within a column packed with ice or snow. The adsorption enthalpy of a trace gas, ΔHads, is readily obtained from its retention time as function of temperature. The study of the adsorption enthalpy of acetone on ice is chosen due to its recent importance to the atmospheric chemistry community. The measured ΔHads on a packed column filled with ice spheres (400 μm<Ø<500 μm) (−54.4±7.6 kJ mol−1, 2σ) and on a packed column filled with aged snow (−56.0±2.8 kJ mol−1, 2σ) are in agreement with the literature values obtained using other analytical techniques, i.e., low pressure ice-coated wall flow tube reactors and volumetric methods. The possibility for the APCI-MS to measure ΔHads of acetone with different ice surfaces, and ΔHads of other species of atmospheric interest, is also discussed.