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At least 793 records · Page 44Linked to original sources
PubMed1992

Resolution of terfenadine enantiomers by beta-cyclodextrin chiral stationary phase high-performance liquid chromatography.

Enantiomers of terfenadine were resolved by high-performance liquid chromatography (HPLC) using a chiral stationary phase (CSP) column packed with beta-cyclodextrin (beta-CD) covalently bound to silica. Separation was achieved in both the reverse phase and normal phase modes. Resolution of enantiomers was confirmed by ultraviolet-visible absorption, circular dichroism, and mass spectral analysis.

Chromatography, High Pressure Liquid↗
PubMed1976

Further studies on the blue and near ultraviolet reversible photoreaction with an intracellular particulate fraction of the fungus, Alternaria tomato.

Further studies have been made on the blue and near ultraviolet-reversible photoreaction in a cell-free system of the fungus Alternaria tomato, prepared by two-layer sucrose density gradient centrifugation. A light-minus-dark difference spectrum of the supernatant fraction showed a dip in the near ultraviolet region, mainly at 280 nm, when irradiated with near ultraviolet light which could not be reversed by following the initial irradiation with blue light. The difference spectrum of the dialyzed particulate fraction, located in the 68% sucrose band, showed a peak absorbance in the blue region, mainly at 400 nm, when irradiated with near ultraviolet light, and also could not be reversed by blue light. When the particulate fraction plus the supernatant fraction was irradiated with near ultraviolet light, the increment rate of peak absorbance in the blue region increased compared to that of the particulate fraction lacking the supernatant, and both peak absorbance in the blue region and the dip in the near ultraviolet region were reversed by irradiation with blue light following the application of near ultraviolet light. Thus, it was concluded that two photoresponsive systems are involved in blue and near ultraviolet reversible photoreaction on an intracellular particulate fraction.

Alternaria↗
PubMed1991

Simultaneous assay for isoniazid and hydrazine metabolite in plasma and cerebrospinal fluid in the rabbit.

A simple procedure for the simultaneous determination of isoniazid and hydrazine metabolite in plasma and cerebrospinal fluid in the rabbit is described. The assay involves organic extraction before and after derivatization of the two compounds and the internal standard, phenelzine. The extract of the derivatized compounds was evaporated to dryness at 40 degrees C and the residue redissolved in the mobile phase (50 microliters). A 25-microliters aliquot was injected into the liquid chromatograph and eluted with acetonitrile-water-triethylamine (70:30:0.4, v/v) containing 5 mM heptanesulphonic acid on a 30-microns C8 precolumn linked to a 10-microns C18 microBondapak column at ambient temperature (25 +/- 1 degree C). The eluate was detected by ultraviolet detection at 320 nm.

Animals↗
PubMed2000

Quantitative analysis of hydrophobic pulmonary surfactant proteins by high-performance liquid chromatography with light-scattering detection.

A new method for the separation and quantification of two hydrophobic lung surfactant proteins (SPs) is described. It is based on size-exclusion chromatography using the apolar stationary phase butyl silicagel with a pore size of 30 nm and isocratic elution with chloroform, methanol and trifluoroacetic acid. The samples were prepared from sheep lung lavage fluid by centrifugation and fractional extraction with butanol and chloroform-methanol. The chromatograms show three peaks in the elution order SP-B, SP-C and lipids. A small peak ahead of SP-B, which disappeared after reduction with 2-mercaptoethanol, was oligomeric SP-B. The response of the evaporative light-scattering detector was non-linear. For preparative high-performance liquid chromatography ultraviolet detection at 279 nm is recommended.

Chromatography, High Pressure Liquid↗