Two methods of purification of the plantaricin ST31, a bacteriocin produced by Lactobacillus plantarum ST31 are used in this study – the method of ammonium sulfate precipitation, Sep-pack C18 cartridge and reverse-phase HPLC chromatography on C18 Nucleosil column, and the method of direct purification by cation exchange SP Sepharose Fast Flow column Amersham (Pharmacia Biotech). The purity of t...

An ultra high performance liquid chromatography (UHPLC) method using an Agilent 1290 Infinity LC system with an Agilent 1290 Infinity Diode Array Detector (DAD) was developed for the separation of Shenmai injections. Good separation of complex systems was achieved by connecting two columns: an Agilent ZORBAX Eclipse Plus C18 column (2.1 mm × 100 mm, 1.8 μm) and an Agilent ZORBAX SB C18 (2.1mm ×...

We here report a reversed-phase HPLC method for the determination of free cortisol in human urine, using methylprednisolone as the internal standard. Before chromatography, samples were extracted with a C18 solid-phase extraction column and the steroids were separated on a LiChrospher 100 C18 column with a mobile phase of methanol/acetonitrile/water (43/3/54 by vol). Linearity, precision, and a...

Sulfonamides were extracted from honey with acetate buffer (pH 5.0), and cleaned up by solid phase extraction (SPE) procedure. The liquid chromatography (LC) separation was carried out on RP C18 column using acetic acid and acetonitrile as the mobile phase in gradient mode and monitored with fluorescence detector, after pre-column derivatisation. Recoveries from spiked honey were above 80%, and...

a rapid and reproducible method is described that employs solid phase extraction (spe) using dichloromethane, followed by gas chromatograph-mass spectrometry for the determination of toxic toluene, xylene and cumene (txc) from different lake water of dhaka mega city of bangladesh. the method was applied to detect and quantify txc in water samples collected from surface and 30 cm depth of water....

A novel uronic acid-containing glycosphingolipid (UGL-1) was isolated from the ascidian Halocynthia roretzi. UGL-1 was prepared from chloroform-methanol extracts and purified by the use of successive column chromatography on DEAE-Sephadex, Florisil, and Iatrobeads. Chemical structural analysis was performed using methylation analysis, gas chromatography, gas chromatography-mass spectrometry, ma...

Fast analytical methodologies are mandatory for large scale metabolic profiling. Here, we present a thorough evaluation of different column chemistries in combination with different mobile phases for fast LC-MS urinary metabolic profiling. Three porous HILIC materials were investigated, next to core-shell C18-, XB-C18- and PFP-RPLC material. The performance of the selected column chemistries wa...

Ten new polyhydroxyolean-12-ene pentacyclic triterpenoidal saponins, named rogchaponins 1-10, were isolated from the methanolic extract of the roots of Camellia sinensis by a series of chromatographic methods (silica gel flash column and C18 MPLC followed by C18 HPLC). Their structures were established by 1D and 2D-NMR techniques along with IR and HR-TOF-MS. Rogchaponins R4 ( 4) and R5 (5) show...

The performance of isocratic separations of 11 pollutant phenols (PP) using monolithic (Chromolith RP-18e) and conventional reversed-phase 5 microm (Luna and Purospher C18) and 4 microm (Synergi C12) particulate size columns, selected from high purity silica materials, has been compared. The separations have been optimized based on a previously optimized separation in which a reversed-phase C18...