A high performance liquid chromatography method was studied for determination of 18 ?-glycyrrhetinic acid in Glycyrrhiza glabra L. (licorice) extract. The operating condition were C-18 reversed phase column (VP-ODS, (250×4.6 mm, 5 mm)) at room temperature, acetonitril/phosphoric acid (3/1) as mobile phase, at flow rate of 0.6ml/min (0-8min), 0.4ml/min (8-20min) and UV detection at 230 nm. The...

A high performance liquid chromatography method was studied for determination of 18 ?-glycyrrhetinic acid in Glycyrrhiza glabra L. (licorice) extract. The operating condition were C-18 reversed phase column (VP-ODS, (250×4.6 mm, 5 mm)) at room temperature, acetonitril/phosphoric acid (3/1) as mobile phase, at flow rate of 0.6ml/min (0-8min), 0.4ml/min (8-20min) and UV detection at 230 nm. The...

Pigments of the flavanol-anthocyanin (F-A+) type detected earlier in wine are synthesized using a protocol adapted from the synthesis of procyanidin dimers. The F-A+ adduct thus obtained is purified by countercurrent liquid-liquid partition, currently referred to as countercurrent chromatography (CCC). The solvent system consists of tert-butyl methyl ether-n-butanol-acetonitrile-water (2:2:1:5,...

Two strains of Fusarium sporotrichioides and one strain of F. culmorum were shown to produce the mycotoxin moniliformin in rice culture. Identification was by reverse-phase liquid chromatography, thin-layer chromatography, and mass spectrometry.

We compare measurement of the tricyclic antidepressants desipramine, imipramine, nortryptaline, and amitryptaline by reversed-phase "high-performance" liquid chromatography and by gas chromatography/mass fragmentography. The liquid-chromatographic procedure does not require ion-pairing reagents, and involves detection at 215 nm. The within-day and between-day CVs for this method were less than ...

When the free cortisol in urine was analyzed by liquid chromatography after pretreatment with the usual organic extraction, interfering substances having chromatographic behavior similar to that of cortisol and the internal standard precluded accurate measurement. To remove these materials, we processed the organic extract by liquid chromatography with a normal-phase column for clean-up; the sp...

Carbon nanoparticles (CNPs) (6-18 nm in size) were prepared by refluxing corn stalk soot in nitric acid. The obtained acid-oxidized CNPs are soluble in water due to the existence of carboxylic and hydroxyl groups. (13)C NMR measurement shows the CNPs are mainly of sp(2) and sp(3) carbon structure different from CNPs obtained from candle soot and natural gas soot. Furthermore, these CNPs exhibit...

a new method for analysis of benzene, toluene, and xylene (btx) using high performance liquid chromatography-uv detection (hplc-uv) is described and compared to the gas chromatography (gc) method. a charcoal adsorption tube connected to a small pump was used to obtain samples from an atmosphere chamber standard. samples were extracted with methanol and analyzed by hplc-uv. chromatography was is...

A novel, efficient and simple approach for soy phosphatidylcholine analysis according to its fatty acid composition was studied with reverse-phase high-performance liquid chromatography. The reverse-phase high-performance liquid chromatography analysis was performed isocratically using UV detector and simple mobile phase solvents consisting of isopropyl alcohol, methanol, and deionized water in...