Proteomic samples such as human serum are an extreme challenge to study due to the large dynamic range of the proteins of interest. The proteins in human serum can range from those considered “high-abundance” proteins, present at 2%–50% of the total protein mass (typically the μg/mL–mg/mL range) to those considered tissue biomarkers present in the pg/mL–ng/mL range. Multidimensional separation ...

A simple one-step in situ "click" modification strategy was developed for the preparation of hydrophobic organic monolithic columns for the first time. The column morphology and surface chemistry of the fabricated monolithic columns were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, respectively. The chromatographic ...

This paper presents two high performance liquid chromatographic (HPLC) methods used for the separation and determination of artificial sweeteners aspartame, acesulphame K, sodium saccharin, and sodium cyclamate in beverages and special nutritional products (special food intended for specific population groups). All four compounds are soluble in aqueous solutions and can easily be separated and ...

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...