a new method for analysis of benzene, toluene, and xylene (btx) using high performance liquid chromatography-uv detection (hplc-uv) is described and compared to the gas chromatography (gc) method. a charcoal adsorption tube connected to a small pump was used to obtain samples from an atmosphere chamber standard. samples were extracted with methanol and analyzed by hplc-uv. chromatography was is...

A new high-performance liquid chromatography (HPLC) stationary phase was firstly synthesized based on the ionic liquid 2-ethyl-4-methylimidazole chloride. And the performances of the resulting stationary phase were determined by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), and (13)C nuclear magnetic resonance (NMR) spectroscopy. The retention characteristics of the resu...

Molecular species of neutral phospholipids, phosphatidylcholine (PC) and phosphatidylethanolamine (PE), were resolved by reversed-phase high-performance liquid chromatography (HPLC) using mobile phases of acetonitrile-methanol-water containing tetraalkylammonium phosphates (TAAPs). Competitive interactions of TAAPs and analyte solutes with a reversed-phase HPLC column resulted in reduced retent...

Reversed-phase high-performance liquid chromatographic (HPLC) behavior of fluorescent labeled phospholipids (PLs) was studied. Molecular species of phosphatidylethanolamine (PE) derivatized with fluorescein-, thiocarbamoyl-, pyrenesulfonyl-, and dimethylaminonaphthalenesulfonyl (dansyl)-fluorophores were separated on octadecylsilica with a mobile phase of acetonitrilemethanol-water in the prese...

A HPLC method was developed for separation and quantitative determination of inositol tri-, tetra-, penta-, and hexaphosphates. The method included extraction of inositol phosphates with HCl, separation of the inositol phosphates from the crude extract by ion-exchange chromatography, and ion-pair Cl8 reverse phase HPLC analysis using formic acid/methanol and tetrabutylammonium hydroxide in the ...

Using solid-phase extraction columns and "high-performance" liquid-chromatographic (HPLC) analysis, we could determine cyclosporin A and nine of its metabolites in blood, bile, and urine. To facilitate calculations of concentrations of cyclosporin A and its metabolites from the chromatograms, we used cyclosporin D as internal standard. For the HPLC analysis we used two sequential 250-mm analyti...

The preliminary research work carried to find out the concentration of Gentamicin in the raw material. Two different techniques used in this study for the quantification of Gentamicin. They are microbiological assay method and reversed phase HPLC. The concentration of Gentamicin was quantified even at very lower concentration by microbiological assay method and it is sensitive. The test organis...