Abstract An analytical method using gas chromatography isotope ratio mass spectrometry (GC-IRMS) combined with solid phase micro-extraction (SPME) was developed to measure the δ 13C values of six typical volatiles commonly occurring in wine (isoamyl acetate, 2-octanone, limonene, 2-phenylethanol, ethyl octanoate and decanoate) for first time. SPME selected a divinylbenzene/carboxen/polydimethyl...

A new automated method based upon solid phase micro-extraction (SPME)/fast gas chromatography-mass spectrometry (GC-MS) was developed for the quantitative determination of airborne peracetic acid (PAA). The method is suitable for the quick assessment of brief acute exposure as well as for long-term environmental monitoring of PAA and can assist in improving safety and environmental quality in w...

Volatile compounds are responsible for the wine "bouquet", which is perceived by sniffing the headspace of a glass, and of the aroma component (palate-aroma) of the overall flavor, which is perceived on drinking. Grape aroma compounds are transferred to the wine and undergo minimal alteration during fermentation (e.g., monoterpenes and methoxypyrazines); others are precursors of aroma compounds...

In this work, the stability of antioxidant compounds in malting barley seeds before and after production final products is reported. reflection, findings revealed that process fermentation had a significant impact on activity. vitro, capacities were evaluated using DPPH free radical scavenging assay. The results obtained from spectrophotometric analysis showed lowest inhibition value was observ...

Dracocephalum kotschyi (Lamiaceae), as one of the remarkable aromatic plants, widely grows and also is cultivated in various temperate regions of Iran. There are diverse reports about the composition of the oil of this plant representing limonene derivatives as its major compounds. There is no report on cloning of mono- or sesquiterpene synthases from this plant. In the present study, ...

The determination of γ-nonalactone as one of the important odor-active compounds in freshly cooked non-scented rice is reported. It was evaluated by gas chromatography-olfactometry (GC-O) analysis and identified by gas chromatography-mass spectrometry (GC-MS) analysis in the headspace above the freshly cooked non-scented rice samples extracted by using a modified headspace solid-phase microextr...

Multiple field studies have suggested chemistry within a forest canopy is poorly understood due to inadequate detection and quantification of reactive biogenic emissions, such as terpenes. To measure emission rates of terpenes at Blodgett Forest, a coniferous forest in the Sierra Nevada mountains of California, we placed enclosures over branches of the dominant species at the site – Ponderosa p...

The biological and organoleptic properties of Bulgarian yogurt are largely determined by the metabolic activity selected strains Lactobacillus delbrueckii ssp. bulgaricus. HS-SPME-GC-MS technique was used to analyze volatile compounds produced following strains: bulgaricus MG1, MG2, MG3 MG4, MG5 MG6, MG7 MG8. A study optimize conditions SPME performed. optimum extraction aromatic components obt...

This thesis presents different analytical strategies for the study of the degradation of synthetic polymers. Particular attention was given to the mechanisms involved at the beginning of the polymer breakdown. Three model polymers were used in order to assess different degradation rates. The first polymer studied was a stabilised polyether: Poly(ethylene oxide-propylene oxideethylene oxide) tri...

Background: Fritillaria imperialis is an endangered species with pharmaceutical alkaloids that can be effective in reducing blood pressure and reducing cardiac palpitations.   Objective: Comparison of head space solid phase microextraction (HS-SPME) and hydro-distillation (HD) techniques in determination of essential oils in Fritillaria imperialis Methods: Quality and quantity determination o...