Phospholipid fatty acids (PLFAs) are key components of microbial cell membranes. The analysis of PLFAs extracted from soils can provide information about the overall structure of terrestrial microbial communities. PLFA profiling has been extensively used in a range of ecosystems as a biological index of overall soil quality, and as a quantitative indicator of soil response to land management an...

A gas chromatography (GC) method including a full evaporation headspace (FE-HS) sampling technique was developed for rapidly and simultaneously measuring volatile products for acetone-butanol-ethanol (ABE) fermentation. In this method, a small volume (<50 μL) of fermentation broth was directly injected into a sealed headspace sample vial (22 mL) and the mass transfer of acetone-butanol-ethanol ...

Menthol is widely used as a fragrance and flavor in the food and cosmetic industries. It is also used in the medical and pharmaceutical fields for its various biological effects. Gas chromatography (GC) is considered to be a sensitive method for the analysis of menthol. GC chromatographic separation was developed using capillary column (VF-624) and a flame ionization detector (FID). The method ...

The main effects of six experimental factors on the efficiency of HS (headspace) extraction in headspace gas chromatography--flame ionization detector (HS-GC-FID) determination of twenty organic solvents routinely used in production of pharmaceuticals were obtained on the basis of the results of experiments carried out according to the Plackett-Burman factorial design. The effects were used as ...

BACKGROUND Urinary organic acids are water-soluble intermediates and end products of the metabolism of amino acids, carbohydrates, lipids, and a number of other metabolic processes. In the hereditary diseases known as organic acidurias, an enzyme or co-factor defect in a metabolic pathway leads to the accumulation and increased excretion of one or more of these acidic metabolites. Gas chromatog...

Acrylates have been widely used in the synthesis of pharmaceutical polymers. The quantitation of residual acrylate monomers is vital as they are strong irritants and allergens, but after polymerization, are relatively inert, causing no irritation and allergies. Poly(ethylene oxide) (PEO) hydrogels were prepared using pentaerythritol tetra-acrylate (PETRA) as UV crosslinking agent. A simple, acc...

A rugged jet expansion module was designed, built, and utilized to sample liquefied gas for gas chromatography-discharge ionization detector (GC-DID) analysis. The module is inserted at an intermediate stage between a higher pressure sample cylinder and lower pressure gas injection manifold. The title jet module permits selection of liquid-phase or vapor-phase sampling by setting the valve-cyli...

In this study we have investigated the possibility of processing waste rubber gloves using pyrolysis. Y-zeolite catalyst was employed to upgrade the pyrolysis products to give higher yields of valuable aromatic compounds such as toluene and xylenes. The composition of the pyrolysis products was determined using gas chromatography with linked mass spectrometry (GC-MS), gas chromatograph equipped...

Present study aims the optimisation and validation of the extraction procedures for the determination of polycyclic aromatic hydrocarbons (PAHs) in sediment samples. As analytical techniques, gas chromatographymass detector (GC-MS) and gas chromatography-flame ionization detector (GC-FID). The optimized methods were soxhlet extraction, ultrasonic bath extraction and solid phase micro extraction...

Many herbal medicines pertain characteristic odour which indicates the volatility of some compositions. Most of the volatiles constituents have low molecular weight, typically, monoterpenes, sesquiterpenes and phenylpropanes and their oxygenated derivatives (Harnone, 1998). Some herbs contain high content of volatile oils from which the oil themseleves are used as drugs, for example eucalyptus ...