A reverse phase high-pressure liquid chromatography system for rapid separation of various retinoids (vitamin A and its analogs) with little or no degradation is described. This method permits detection of as little as 22 pmol of retinoic acid. The procedure has been applied to the study of retinoic acid metabolism in vitamin A-deficient hamsters.

many modern analytical methods deal with the trace-level determination of compounds of interest in highly complex environmental samples by means of chromatographic techniques. the introduction of a “clean” sample into an analytical instrument can make analyses easier and prolongs the equipment life. the use of solid-phase extraction (spe) has grown and is a fertile technique of sample preparati...

in this project, eggshell membrane was used as a solid phase extraction sorbent for extraction of morphine followed by hplc analysis. at first, raw eggshell membrane was used and then, because of low adsorption of morphine on untreated eggshell membrane (

background and objectives: the addition of plasticizers (mainly phthalates and adipates) makes plastic flexible and popular for packaging, storing and preserving food, water, and so on. the most widely used plasticizer in food contact applications is di-ethylhexyl phthalate (dehp) though being suspected to have carcinogenic and estrogenic properties. the aim of this study is application of magn...

Abbreviations: ACN: Acetonitrile; AvBD: Avian Beta-Defensin; CAM: Carbamidomethylation; 1,5 DAN: 1,5 Diaminonaphthalene; DHB: 2,5 Dihydroxybenzoicacid; DTT: Dithiothreitol; FITC: Fluorescein Isothiocyanate; IAA: Iodoacetamide; ISD: In Source Decay; MALDI-MS: Matrix-Assisted Laser Desorption Ionization Mass Spectrometry; m/z: Mass/Charge; PI: Propidiumiodide; RP-HPLC: Reverse Phase-High Pressure...

PURPOSE: To develop an alternate high performance liquid chromatographic method (HPLC) for the analysis of the positive inotropic agent, milrinone, in rat and human plasma. METHODS: To plasma samples (0.1 mL), containing milrinone and the commercially available internal standard, amrinone, were added 0.15 mL of water and 0.35 mL of acetonitrile. Tubes were briefly vortexmixed and centrifuged. T...

We used reverse-phase high-pressure liquid chromatography to measure free norepinephrine and dopamine simultaneously in human urine. Samples were treated with alumina, and the catecholamine(s) then eluted from it were directly injected onto a reverse-phase column (octadecyl-silica stationary phase), with 0.17 mol/liter acetic acid as the mobile phase and ultraviolet detection at 280 nm. The ass...

This article describes reverse phase high-performance liquid chromatography (RPHPLC) methods for determination of diuretics in different human body fluids (whole blood, plasma, serum or urine). Sample preparation procedures, including solid-phase extraction, liquid-liquid extraction, dilution, precipitation as well as automated RPHPLC procedures, are discussed in order to present the advantages...

A procedure is described for purifying a low molecular weight peptide that induces differentiation in mouse myeloid leukemia M1 cells. The factor comes from the conditioned medium of macrophage-like cells differentiated from mouse myeloid leukemia M1 cells. The procedure for purification includes gel filtration on Sephadex G-15, anionic exchange chromatography, thin-layer chromatography, revers...