static headspace Dotaz Zobrazit nápovědu
BACKGROUND: A comparative analysis by using static headspace (HS) and steam distillation (SD) GC-MS of the volatile and the semi-volatile secondary metabolites from leaves of cultivated Majorana syriaca. METHODS: The essential oils endogenous to cultivated thyme were isolated and identified by HS-GC-MS technology and compared to those from SD-GC-MS. RESULTS: The HS-GC-MS results showed that the Palestinian cultivated thyme is rich in monoterpene hydrocarbons and phenolic monoterpenes such as alpha-phellandrene, alpha-pinene, beta-myrcene, m-cymene, p-cymene, gamma-terpinene, thymol and carvacrol. In all the samples gamma-terpinene, p-cymene, thymol and carvacrol were the most abundant compounds. CONCLUSIONS: HS and SD-GC-MS have proved that most of the cultivated thyme samples examined has thymol isomer as the major phenolic constituent.
- MeSH
- dobromysl (rod) chemie MeSH
- listy rostlin chemie MeSH
- monoterpeny analýza MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- thymol analýza MeSH
- Thymus (rostlina) chemie MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- Geografické názvy
- Střední východ MeSH
Attempts at quantification of gas contents in the determination of volatile organic compounds in soils were made. The static headspace technique and methanol extraction followed by thermal desorption and gas chromatography were compared. Soils with different physicochemical properties were contaminated by treatment with vapour from an aqueous solution of perchloroethylene (PCE) of the concentration 140 mg l?1. Soil spiking in a modified desiccator took place for up to 24 h. After exposure the samples were analyzed within two days. Gas extraction can rapidly provide quantitative data on PCE concentration in soils. The results were not significantly different from those obtained by more expensive and time-consuming liquid extraction.
