Metabolism of free (nonesteriRed) arachidonic acid (5,8,11,14-cis-eicosatetraenoic acid) via the cyclooxygenase (COX) pathway produces a cascade of biologically active compounds collectively known as prostaglandins (PGs). These include prostaglandin D2 (PGD2), prostaglandin E2 (PGE2), prostaglandin F2 (PGF2), prostacyclin (PGI2) and thromboxane A2 (TXA2) (Figure 1). The analysis of PGs and rela...

possibility of very selective separations that depend on the geometry of the molecules to be separated rather than the more generalized solubility mechanisms acting in gas}liquid chromatography. It should be theoretically possible to design adsorbents for particular separations. In the branch of liquid chromatography known as afRnity chromatography, for example, it is already possible to manufa...

Gas chromatography (GC) is a widely applied technique in many branches of science and technology. For over half a century, GC has played a fundamental role in determining how many components and in what proportion they exist in a mixture. However, the ability to establish the nature and chemical structure of these separated and quantified compounds is ambiguous and reduced, and requires a spect...

Gas chromatography (GC) is generally believed to be restricted to the analysis of ‘volatiles’ and is less applicable to the analysis of so-called ‘heavy’ compounds. The introduction of persilylated glass and fused silicea columns, of thermostable stationary phases and of non-discriminative injection devices in capillary GC (CGC) have made the deRnitions of ‘volatile’ and ‘heavy’ very Sexible. H...

Aliphatic and aromatic mono-, diand polyamines are naturally occurring compounds formed as metabolic products in microorganisms, plants and animals, in which the principal routes of amine formation include the decarboxylation of amino acids, amination of carbonyl compounds and degradation of nitrogen-containing compounds. Accordingly, amines are important indicators of a wide variety of biochem...

nical mixtures found in the formulation and the measurements made on the basis of calibration with these mixtures. Chlorobiphenyl (CB) refers to the individual congener named by the Ballschmiter number. TEQs refer to the sum of the concentration of the congener equivalent to 2, 3, 7, 8 TCDD obtained by using the toxic equivalence factor for each PCB. POLYCHLORINATED BIPHENYLS: GAS CHROMATOGRAPHY

chromatography with cellulose tris(3,5-dimethylphenylcarbamate)-coated phases. Improved resolution of basic analytes. Journal of Chromatography A 728: 195}199. Hostettmann K, Marston A and Hostettmann M (1997) Preparative Chromatography Techniques. Applications in Natural Product Isolation. Berlin: Springer. Li T-S, Li J-T and Li H-Z (1995) ModiRed and convenient preparation of silica impregnat...

A basic discussion of the principles of gas chromatography and a description of a combustion gas analyzer using this chemical analysis techniqlJe are presented. During the past several years the combustion gas analyzer has been used extensively in airbreathing propulsion research projects at the APL Propulsion Research Laboratory to analyze samples from supersonic combustion and fuel-air mixing...

background and objective: reduced fat cheese often exhibits poor sensory quality due to the reduction of fat, which plays a critical role in flavor and texture. therefore, there is the challenge to produce a reduced fat cheese with improved sensory attributes and texture that is also comparable to its full-fat counterpart. the main objective of this research was to investigate the effect of dif...