Methods: A simple, isocratic reverse-phase high performance liquid chromatographic (RP-HPLC) method has been developed for simultaneous estimation of methotrexate, dexamethasone and indomethacin using ibuprofen (IBP) as internal standard with photodiode array detection at 254 nm. The process was carried out on C18 column (5 μm, 250 mm X 4.6 mm) using methanol: orthophosphoric acid (1.67 % v/v) ...

Phytosterols are a group of steroids alcohols which had been regarded as a functional factor. An unknown compound in phytosterol samples and phytosterol standard samples was detected by HPLC using symmetry C18 column. The quantity of the compound was increased with the enrichment of β-sitosterol. After being collected and analyzed by GC-MS and compared with standard diagram from Wiley and Nist ...

A specific ultra-performance liquid chromatography–mass spectrometry (UPLC–MS) method was developed for the simultaneous determination of puerarin, daidzein, baicalin, wogonoside and liquiritin in rat plasma. Chromatographic separation was performed on a C18 column packed with 1.7 m particles by a linear gradient elution. The analytes and carbamazepine (internal standard, I.S.) were monitored i...

In this precise, accurate, and specific liquid-chromatographic procedure for determining progesterone in serum, the serum is diluted 10-fold with water/methanol (65/35 by vol), and the progesterone is extracted from the sample by passage through a column of graphitized carbon black (Carbopack B, Supelco). After washing the column, we elute the progesterone with chloroform/methanol (90/10 by vol...

We describe a rapid, simple HPLC method routinely used in our clinical laboratory for determining amiodarone and its metabolite desethylamiodarone. These compounds are released from serum proteins by pretreatment with an acidic solution and then extracted onto a C2 reversed-phase clean-up column. After elution from the extraction column, the compounds are separated and quantified by HPLC with a...

A tidal bore is a wave propagating upstream as the tidal flow turns to rising. It forms during spring tide conditions when the flood tide is confined to a narrow funneled channel. To date, theoretical and numerical studies rely upon physical experiments to validate the developments, but the experimental data are limited mostly to visual observations and sometimes free-surface measurements. Here...

The fish gill is the most physiologically diversified vertebrate organ, and its vasculature the most intricate. Application of vascular corrosion techniques that couple high-fidelity resins, such as methyl methacrylate, with scanning electron microscopy yields three-dimensional replicas of the microcirculation that have fostered a better appreciate gill perfusion pathways. This is the focus of ...

On the basis of the integrable Kaup–Boussinesq version of the shallow-water equations, an analytical theory of undular bores is constructed. A complete classification for the problem of the decay of an initial discontinuity is made.