Invited review article: an odor-sensing system--powerful technique for foodstuff studies.

This work examines gas sensor array technology combined with multivariate data processing methods and demonstrates a promising potential for rapid, non-destructive analysis of food. Main attention is focused on detailed description of sensor used in e-nose instruments, construction, and principle of operation of these systems. Moreover, this paper briefly reviews the progress in the field of artificial olfaction and future trends in electronic nose technology, namely, e-nose based on mass spectrometry. Further discussion concerns a comparison of artificial nose with gas chromatography-olfactometry and the application of e-nose instruments in different areas of food industry.

Development of headspace solid-phase microextraction-gas chromatography method for the determination of solvent residues in edible oils and pharmaceuticals.

The application of headspace solid-phase microextraction for isolation and enrichment of solvent residues from oils and pharmaceuticals is discussed. The optimal parameters for isolation and preconcentration of common process solvents (hexane, benzene, toluene and selected chloroderivatives of hydrocarbons) were established. Four fiber types (100 microm polydimethylsiloxane (PDMS), 75 microm Carboxen-PDMS, 65 microm PDMS-divinylbenzene and 85 microm polyacrylate) were evaluated to choose the most efficient coating, able to absorb the greatest amount of analytes. GC-flame ionization detection (FID) and GC-electron-capture detection systems were used for quantitative and qualitative analysis, adequately to the appropriate group of the analytes. For all compounds the limit of detection (LOD), linearity, dynamic range, repeatability and intermediate precision were estimated.

Comparison of extraction techniques for gas chromatographic determination of volatile carbonyl compounds in alcohols.

Two extraction procedures, i.e. conventional liquid-liquid extraction (LLE) and liquid solid-phase microextraction (SPME) for extraction of the oximes formed after derivatization of carbonyl compounds with o-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine (PFBHA) in alcoholic solutions have been compared. The limit of detection for LLE followed by GC-ECD determination of C1-C6 was in the range of 0.23-3.3 microg/L, whereas for liquid SPME 0.005-0.33 microg/L. Both methods elaborated can be applied to the determination of carbonyl compounds present in spirits and alcoholic beverages.

Quantitative determination of hydroxylamine.

This paper is a survey of 66 studies from the literature and presents a review of the quantitative methods most widely used for the determination of hydroxylamine and its salts. Volumetric, electrochemical and spectrophotometric methods are discussed, compared and evaluated.