A gas chromatography-mass spectrometry method for quantification of polyhydroxyalkanoates (PHAs), containing 4-carbon to 16-carbon monomers, even in the absence of standards, was developed. Strong linear correlations existed between PHA carbon number and retention time/response factor (R(2) ≥ 0.987). Based on the correlations, high recovery values, between 100.5% and 114.3%, were obtained for P...

Hyphenated gas chromatography (GC) (Chaturvedi & Nanda, 2010; Coleman III & Gordon, 2006) mainly refers to the coupling of the high-performance separation technique of gas chromatography with 1) information-rich and sophisticated GC detectors which otherwise can be mostly operated as a stand-alone instrument for chemical analysis, and 2) automated online sample preparation systems. The term “hy...

Inverse gas chromatography (IGC) represents a unique reRnement of a classic chromatographic method in which an unknown solid material such as a powder, Rbre or Rlm may be characterized. By reversing the traditional role of unknown mobile phases and known reference stationary phases, the gas}solid chromatographic retention processes may be used to characterize an unknown particulate sample by el...

A gaschromatographic method is presented for the determination of thiopental (and of its metabolite pentobarbital) in cases of severe head injuries treated by induction of therapeutic barbiturate coma. To 1 ml serum the internal standard and saturated ammonium sulphate solution are added. The mixture is extracted by chloroform and the concentrated organic phase is injected into the gaschromatog...

From the chemical point of view, wines are aqueous alcoholic solutions containing more than 1000 components that can be present at high concentrations (g L ), but also at trace levels (ng L ). Some of these components determine the organoleptic properties of wines, while others are signi"cant for classifying their origin and/or for checking whether some adulteration has taken place. Concentrati...

Pyrolysis of agricultural waste to produce fuel gas involves formation of tars as noxious by-products. In this paper the qualitative analysis of tars formed during pyrolysis of rice husks is presented, based on identification by gas chromatography-mass spectrometry and interpolation of retention times on a polyaromatic hydrocarbon index scale. The influence of some reaction parameters on produc...

Derivatization reactions are meant to transform an analyte for detectability in Gas Chromatography (GC) or other instrumental analytical methods. Derivatization in GC analysis can be defined as a procedural technique that primarily modifies an analyte’s functionality in order to enable chromatographic separations. A modified analyte in this case will be the product, which is known as the deriva...

This review describes analytical methods developed for the separation, identification and quantitation of trans-isomers of unsaturated fatty acids. Although these methods are applicable to a wide variety of food matrices, we have particularly emphasised the analysis of trans unsaturated fatty acids in milk fat. Various methods are described such as infrared spectroscopy, direct gas chromatograp...

Sera from patients being treated with phenytoin were analyzed for the drug by spectrophotometry, gas chromatography, radioimmunoassay, enzyme immunoassay, and liquid chromatography. The essay values obtained were intercompared statistically. Enzyme immunoassay and liquid chromatography appear to be attractive alternatives to the more traditional methods of spectrophotometry and gas chromatograp...

Spectroscopy Laboratory, The Dow Chemical Company, Midland, Michigan, USA In December 1955 or thereabouts, the authors coupled a homemade gas chromatograph to a research time-of-flight mass spectrometer constructed by W. C. Wiley, I. H. McLaren, and D. B. Harrington. This unique gas chromatography/mass spectrometry (GC/MS) instrument generated mass spectra at a lo-kHz rate for display on an osc...