One of the ultimate goals of ion chromatography is to determine both anions and cations found in samples with a single chromatographic run. In the present article, recent progress in ion-exclusion/ion-exchange chromatography for the simultaneous determinations of inorganic anions and cations are reviewed. Firstly, the principle and the control for the simultaneous separation and detection of ...

Trichloroacetic Acid (TCA) was used as an efficient catalyst for the synthesis of highly functionalized piperidines via a one-pot five-component reaction of aromatic amines, aromatic aldehydes and β-keto esters in MeOH at room temperature. The remarkable advantages offered by this method are good yields, simple procedure, short reaction times, no need to column chromatography and an easy wo...

Calystegines were isolated from the root cultures of Physalis divaricata, P. pubescens, P. philadelphia,and P. philadelphia (solanaceae). Calystegines of P. divaricata were identified as calystegine A3, A5, B1 and B2, with concentrations of 6.99, 4.41, 8.52, and 14.7 ?g/g in fresh mass, respectively. Root cultures of P.pubescens contain calystegine A3, B1 and B2, P. philadelphia only contains ...

The possibility of carbohydrate separation in BEH HILIC (Ethylene Bridged Hybride, Hydrophilic Interaction Liquid Chromatography) column was studied by ultra-performance liquid chromatography (UPLC) with evaporative light scattering detector (ELSD) and mobile phase containing amine compounds as modifiers. The chromatography conditions and ELSD parameters were optimized to separate five typical ...

2 Introduction Column liquid chromatography (LC) systems are the mainstay in modern laboratory practice for both analysis and preparative isolation of natural and synthetic organic samples. Standard highand medium-pressure column LC uses an essentially one-dimensional (1D) format, (i.e., a cylindrical column onto which a single sample is injected). Optimum performance laminar chromatography (OP...

the dried aerial parts of scutellaria lateriflora l. (family labiatae), have been used for many years as a domestic remedy for epilepsy, hysteria, and nervous tension states. although several phytochemical investigations have been made regarding the constituents present in this species (i. e. flavonoids, iridoids), none has been recorded concerning the cuticular wax. using thin-layer chromatogr...

The analysis and characterization of lipids andwaxes is of great importance in the food industry, pharmaceutical and cosmetic industry, in surfactant and detergent technology and in natural product research. Lipid analysts have always been on the forefront of developments in separation sciences and new techniques in chromatography have often been developed for the separation of lipids. The Rrst...

We cloned XYL1, a Scytalidium acidophilum gene encoding for an acidophilic family 11 xylanase. The XYL1p protein was expressed in Pichia pastoris using the pPICZalphaA expression plasmid. The secreted protein was purified by TAXI affinity column chromatography. The purified XYL1p showed an optimum activity at pH 3.2 and 56 degrees C. The Michaelis-Menten constants were determined.

In the literature (1) and in commercial advertising, one can often find material descriptions of chromatographic retention that use the terms hydrophilic interaction liquid chromatography (HILIC) and aqueous normal phase (ANP) in such a manner that they can be construed to be identical. However, in reality, there should be (and there is) a real difference between these two modes of retention an...