Gas-Liquid Chromatographic Separation and Determination of Methylamines

Gas-liquid chromatographic determination

A method for the determination of total bile acids in human feces that is suitable for routine application is described and discussed. Bile acids are extracted from freezedried feces with acetic acid and toluene, in the presence of the i?ternal standard 23-nordeoxycholic acid. After saponification of the extract, bile acids and the internal standard are methylated and converted by mild chromic ...

Gas-liquid chromatographic determination of nicotine and cotinine in plasma.

We report a procedure for determining nicotine and cotinine in plasma. Nicotine is extracted from 1 ml of plasma with diethyl ether, back extracted, and analyzed by gas-liquid chromatography with a nitrogen/phosphorus detector. Nicotine and its internal standard, modaline, had retention times of 1.9 and 2.9 min, respectively. Cotinine is then extracted from the same plasma with dichloromethane ...

Gas-liquid chromatographic determination of mono- and diiodotyrosines in serum.

A sensitivie, reliable gas-chromatographic assay for monoiodotyrosine and diiodotyrosine in human serum is reported. The oxazolidinone-heptafluorobutyric anhydride derivatives allow the quantitation of both compounds in the linear range of 0.2 to 7.6 mg/L of serum. Analytical recovery averaged 88%, and mean accuracy and within-run precision were 98 and 2%, respectively. Concentrations of monoio...

Simultaneous Gas-liquid Chromatographic Determination of Aldoses and Alduronic Acids

Aldoses and alduronic acids can be simultaneously identified and quantitated by wide-bore capillary gas-liquid chromatography. The aldoses are converted to alditol acetates and the alduronic acids are converted to their corresponding N-propylaldonamide acetates. Standard mixtures containing as little as 100 ng each of arabinose, xylose, mannose, galactose, glucose, inositol, mannuronic, glucuro...

Gas-liquid partition chromatography: the separation and micro-estimation of ammonia and the methylamines.