This HPLC method for measuring antipyrine, lorazepam, and indocyanine green in 0.5 mL of plasma can be used in studies of liver function in which these "model" compounds are used. After a fast, simple, one-step extraction procedure with acetonitrile, an isocratic HPLC system is used, with a single detection wavelength (214 nm) and a single internal standard (1-acetamidopyrene). The mobile phase...

separation of ten sedative- hypnotic drugs was performed by rp-hplc using mixed micellar mobile phase. effect of temperature, type and amount of organic modifier in mobile phase on efficiency (n) and asymmetry factor (b/a) showed that, the appropriate conditions for a good separation were 35°c and 7% (v/v) butanol in mobile phase.  variations of selectivity factor versus butanol concentration, ...

We present a rapid, sensitive, and automated HPLC method with direct resolution of l-folinic acid (l-FA), d-folinic acid (d-FA), and 5-methyltetrahydrofolate (5MTHF) from plasma samples. Plasma (500 microL) is first extracted on solid phase (RP-18 cartridge). The dI-FA peak is collected on-line from a reversed-phase column (RP-8, 119 x 2 mm, 4 microns: HPLC 1) and then automatically loaded onto...

Relative hydrophobicity and lipophilicity of 63 compounds with known permeability through the blood-brain barrier (BBB) was examined by partitioning in aqueous dextran-poly(ethylene glycol) two-phase system and octanol-buffer system, and by gradient RP-HPLC at pH 7.4. Combination of the relative hydrophobicity estimates, N(CH(2)) obtained by aqueous two-phase partitioning and the lipophilicity ...

We present two new methods for purifying dinosterol (4a,23,24-trimethyl-5a-cholest-22E-en-3b-ol) from sediments for the purpose of hydrogen isotope analysis via gas chromatography–isotope ratio mass spectrometry (GC–IRMS). The first method uses reversed phase-high performance liquid chromatography (RP-HPLC) to purify dinosterol from structurally similar 4a-methyl sterols that co-elute on GC ana...

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 (