Comprehensive two-dimensional liquid chromatography (LC×LC) using the Agilent 1290 Infi nity 2D-LC Solution with DAD and MS detection is applied for the analysis of citrus oils. The developed method uses normal phase liquid chromatography in the fi rst dimension and reversed-phase liquid chromatography in the second dimension. This combination provides good orthogonality and is valuable for pro...

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 r...

Garrido JL and Zapata M (1996) Ion-pair reversed-phase high-performance liquid chromatography of algal chlorophylls. Journal of Chromatography A 738: 285. Hodgson DA, Wright SW and Davies N (1997) Mass spectrometry and reverse phase HPLC techniques for the identiRcation of degraded fossil pigments in lake sediments and their application in palaeolimnology. Journal of Paleolimnology 18: 335. Jef...

A blocker of postsynaptic acetylcholine receptors was isolated from venom of the Eastern green mamba Dendroaspis angusticeps, by gel filtration, ion-exchange and reverse phase high performance liquid chromatography. The isolated component blocks neuromuscular transmission and responses to exogenously applied acetylcholine in isolated chick biventer cervices preparations. These results suggest t...

a simple, inexpensive and efficient method was used for extraction and determination of fexofenadine and levocetirizine with three–phase hollow fiber liquid-phase microextraction and high-performance liquid chromatography. several parameters influencing the extraction recoveries such as the nature of organic extraction solvent, ph of donor and acceptor phases, stirring rate, extraction time and...

The use of aqueous mixed micellar system consisting of sodium dodecyl sulfate (SDS) and polyoxyethylene (23) dodecanol (Brij-35) as the mobile phase in reversed-phase liquid chromatography was studied. A group of chlorophenols was used as the test mixture. Adding organic modifier to the system showed that the use of low concentrations of organic additives improves efficiency in SDS/Brij-35 mixe...

background ziziphora tenuior l. known as kakuti in persian, is used in traditional medicine for fever, dysentery, uterus infection and as an analgesic. it is used also in the treatment of gastrointestinal disorders as carminative, or remedy of diarrhea or nausea. major components of plant essential oil including pulegone, isomenthone, thymol, menthone, and piperitone are suggested to be respons...