Pyrolysis gas chromatography of some sterols

Quantitative structure–retention relationships applied to liquid chromatography gradient elution method for the determination of carbonyl-2,4-dinitrophenylhydrazone compounds

“…This descriptor also correlates with HPLC retention index working in linear gradient elution mode for a set of 2-n-ketoalkanes-2, 4-dinitrophenylhydrazones. Similar results were found using the number of carbon atoms as molecular descriptor [8].…”

“…Kováts methodology [8], the linear aldehydes ethanal-DNPH, propanal-DNPH, butanal-DNPH, pentanal-DNPH, hexanal-DNPH and octanal-DNPH were used to obtain an equation that linearly correlates the experimental log k with the retention index (RI) established for each linear aldehyde as 200, 300, 400, 500, 600 and 800, respectively. This was applied to experimental data obtained using C 18 and cyano columns in isocratic elution mode.…”

“…These compounds can reach the atmosphere from the exhaust of motor vehicles and other equipment using hydrocarbon and alcohol as fuels [11]. A usual method for the analysis of carbonyl compounds involves HPLC-UV analysis of previously obtained 2,4-dinitrophenylhydrazones (DNPH) derivatives [8,14].…”

Sublimation Thermodynamic Parameters for Cholesterol, Ergosterol, β-Sitosterol, and Stigmasterol

“…The data from vapor pressure measurements presented below confirmed the same. Although in this work decomposition of samples was not detected in the temperature region of interest, it is important to note that the existence of dehydrogenation or hydrogenation reactions 36,37 has been reported in the literature under very different reaction conditions.…”

Gas chromatography

“…Novel applications of pyrolysis GC include differentiation of normal and pathological microbial cells (710), pathogenic microorganisms (359,585), and other compounds of biological interest such as proteins, carbohydrates, blood components, glandular secretions, muscle, nut oils, and pollen (624); the identification of surfactants by cleavage of hydrophobic groups (526); the determination of combustible carbon in carbonaceous chondrites (248); the identification of flame retardant textile finishes (170) and fiber analysis for forensic purposes (780); other forensic determinations such as the analysis of adhesives, plastics, soils, drugs, fibers (918), and thermosetting acrylic resins used in automotive enamels (558); the pyrolysis of the organometallic compounds, tetramethyltin (433) and trimethylantimony (694); the direct determination of organic carbon in water by reductive pyrolysis (845); the determination of chlorine and bromine (156) and oxygen (676) in organic compounds; the pyrolysis of copolymers with methods developed for distinguishing between copolymers and their homopolymer mixtures (13,363); and the pyrolysis of sterols (289).…”