Normal and cyclic alkanes and alkenes form stable gas-phase ions in air at atmospheric pressure from 40 to 200°C when moisture is below 1 ppm. Ionization of alkanes in a (63)Ni source favored charge transfer over proton transfer through pathways involving [M-1](+) and [M-3](+) ions. Ion mobility spectra for alkanes showed sharp and symmetrical profiles while spectra for alkenes suggested fragmentation. Ion identifications were made by using mass spectrometry, and ionization pathways were supported by using deuterated analogs of alkanes and alkenes. Alkanes were ionized seemingly through a hydrogen abstraction pathway and did not proceed through an alkene intermediate. New methods for interpretation of mobility spectra utilizing ion mobility spectrometry, atmospheric pressure chemical ionization mass spectrometry, chemical ionization mass spectrometry, and ion mobility spectrometry-mass spectrometry data were demonstrated.

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New data are presented of the post‐common‐envelope binary VW Pyx and its associated planetary nebula (PN), K 1‐2. The central star is found to be a single‐lined (and possibly double‐lined) spectroscopic binary and is a good candidate for a system in which the main‐sequence secondary star is more massive than the subdwarf primary star. The old PN has a high excitation level and a measured electron temperature, TO∼ 17 000 K for an assumed log ne= 2.7 cm−3. The so‐called ‘jets’ are found to be lower‐ionization regions with TN∼ 11 000 K and TO∼ 16 000 K with log ne∼ 2.5 cm−3 and with low, but fairly typical, PN abundances. We discuss possible histories for K 1‐2 and the jets. However, there are still many unknowns in the study of accretion and jet formation for such PN binary central stars.

???The definitive version is available at www.blackwell-synergy.com '. Copyright Blackwell Publishing. DOI: 10.1111/j.1365-2966.2005.08898.x [Full text of this article is not available in the UHRA]We present intermediate-resolution, phase-resolved spectra of the close-binary systems EC 11575???1845 and V664 Cas, the central star of the planetary nebula HFG 1. Both systems have a very rich emission-line spectrum originating from the face of the cool star, which is irradiated by the hot subdwarf star. The H i emission lines are wide, consistent with Stark broadening. These have a complex shape due to strong absorption near the line centre. We report on new spectroscopic orbits for both subdwarf stars, based on radial velocity measurements of their He ii lines. The orbits of the heated face of the cool companions were measured from narrow emission lines, and from the wide H i profiles; some differences were found between ions. At phases around 0, absorption lines from the photosphere of the secondary star of V664 Cas are seen. These are used to estimate a spectral type of mid-F to early K, and we report on their radial velocities. Synthetic spectra from the non-local thermodynamic equilibrium model atmospheres were used to fit features in the optical spectrum of the hot subdwarf star of EC 11575???1845, from which we estimate Teff= 105 000 ?? 20 000 K, log g= 6.7 ?? 0.3, log nHe/nH=???0.8 ?? 0.1 . Finally, we consider the most likely range of component masses for these two systems

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