Principle Chromatographic procedures allow a separation of substance mixtures with the aid of a stationary separating phase and a mobile phase. In gas chromatography the mobile phase is a gas. The mobile phase, to which the mixture to be separated is added, transports the substance mixture through the separation column at a constant flow rate. Interactions occur between the mobile phase and the...

We evaluated the Hewlett-Packard 5995B benchtop capillary gas chromatograph-mass spectrometer (GC-MS) for its ability to identify drugs commonly detected and (or) measured in the clinical toxicology laboratory. Initial experiments indicated that the instrument as originally configured, with an isolation valve between the gas chromatograph and mass spectrometer, was unsatisfactory for the identi...

Gas-liquid chromatography of cellular fatty acids was used in automatic identification of clinical bacterial isolates. The intraspecies variation in the occurrence of fatty acids and the variation in the relative gas-liquid chromatography peak areas of different fatty acids were evaluated and compared with the relative peak areas of these acids. A new chromatogram comparison method involving th...

Diffusates from seedlings and root exudates from 6-week-old plants of a monoecious line of cucumber, Cucumis sativus L., contained considerably higher levels of gibberellin-(GA-) like substances than did those from plants of an isogenic gynoecious line. Most of the GA-like activity was found in a chromatogram region typical of GA(1) and GA(3); some activity, particularly in root exudates, appea...

The technique of gas-liquid chromatography-chemical ionization mass spectrometry can easily identify trace peaks and unresolved peaks on gas-liquid chromatography, utilizing MH(+) ions of chemical ionization mass spectra. In polyunsaturated fatty acid methyl esters such as C22:5 and C22:6, the determination of molecular weights that are difficult to determine by electron impact mass spectrometr...

Small biochemicals are the end result of all the regulatory complexity present in a cell, tissue, or organism, including transcriptional regulation, translational regulation, and posttranslational modifications. Metabolic changes are thus the most proximal reporters of the body’s response to a disease process or drug therapy. In 1971, Robinson and coworkers1 conceived the core idea that informa...

Leishmaniasis is one of the most important parasitic infections, but current treatments are unsatisfactory due to their toxicity, cost and resistance. Therefore, the development of new antileishmanial compounds is imperative. Many people who live in endemic areas use plants as an alternative to treat the disease. In this paper, we characterised the essential oil from Piper auritum, evaluated it...