Two simple methods using headspace solid-phase microextraction (HS-SPME) coupled to a gas chromatograph with a flame ionization detector were compared for the determination of polycyclic aromatic hydrocarbons (PAH) in soils. These compounds were included in the US Environmental Protection Agency's Priority Pollutants list. Direct hot water HS-SPME extraction and sonication organic extraction fo...

In this research the lipid fraction of two strains of Streptococcus thermophilus was studied. Lipids were extracted by applying Folch method and fractioned by thin layer chromatography (TLC). Fatty acid composition was determined both before TLC, on the total fat extracted, and after TLC on diacylglycerol and apolar fractions. Gas chromatographic analysis was performed by using both flame ioniz...

Background Biodiesel, an alternative energy source, has been attracting increasing worldwide interest in recent decades. It is obtained by base-catalyzed transesterification, resulting in a final mixture consisting of mono-alkyl esters and other by-products (e.g. glycerol, alcohol, free fatty acids). This composition provides a level of operational quality control that enables biodiesel to be m...

A new, simple, precise, and rapid high-performance thin-layer chromatography (HPTLC) method was developed for the analysis of commercial emulsifiable concentrate (EC) formulations of cypermethrin, alpha-cypermethrin, and lambda-cyhalothrin. A known amount of reference grade synthetic pyrethroid and its EC formulation was subjected to TLC, and the amount of pesticide present in the active ingred...

Tabernaemontana catharinensis is a tree rich in indole alkaloids, such as coronaridine and voacangine that have antileishmanial activity. SFE from T.catharinensis using CO2 + 5.1% (m/m) of cosolvent (ethanol, isopropyl alcohol, methanol, water and their mixtures) was studied. The global yields and the compositions of extracts were determined. The data were taken at 250 bar, 45oC, and total solv...

Since the isolation of artemisinin 32 years ago, it has been analyzed by different chromatographic techniques. This work compared the analysis of artemisinin from crude plant samples by GC with flame ionization detection (GC-FID) and HPLC with evaporative light scattering detector (HPLC-ELSD). Data is also presented indicating that GC is suitable for the quantification of two of artemisinin pre...

We introduce a new in-situ instrument, Thermal desorption Aerosol GC/MS-FID (TAG), capable of hourly measurements of speciated organic compounds in atmospheric aerosols. Aerosol samples are collected into a thermal desorption cell by means of humidification and inertial impaction. The sample is thermally desorbed and transferred with helium carrier gas into a gas chromatography (GC) column, wit...

Carduus nutans L. is a biennial plant which is belonging to Asteraceae family known as musk or nodding thistle commonly. Carduus species includes different active ingredients like essential oil, resin, tannin, fatty oil, starch, flavonolignans, polyacetylenes. Importance of phytochemistry and chemical ecology researches increase gradually. The fat extraction was carried out by Soxhlet method wi...

Six cultivars (Franquette, Marbot, Mayette, Mellanaise, Lara, and Parisienne) of walnuts (Juglans regia L.) were collected during the 2001 crop, from Bragança, Portugal. Chemical composition, including moisture, total oil content, crude protein, ash, carbohydrates, and nutritional value, was evaluated. Fat was the predominant component, ranging from 62.3 to 66.5%. Total oil was extracted and an...