in this study, porous scaffolds from poly(d,l-lactic acid) have been prepared via liquid- liquid phase separation method in ternary system of polymer-1,4-dioxane-water. polymer dissolved in dioxane in 1.5, 2.5 and 5 % wt/v and the solvent/non-solvent ratios were 13/87, 15/85 and 17/83. cloud point curves prepared by visual turbidometry. in order to obtain porous scaffolds with inter-connected p...

High-temperature liquid chromatography (HTLC) is recognized today as a valuable technique in reversed-phase high-performance liquid chromatography (RP-HPLC). Column temperature can play a role in reducing analysis time, modifying retention, controlling selectivity, changing efficiency or improving detection sensitivity. The different effects of high temperatures on reversed-phase separations, t...

This review considers some of the difficulties encountered with the analysis of ionised bases using reversed-phase chromatography, such as detrimental interaction with column silanol groups, and overloading which both lead to poor peak shapes. Methods of overcoming these problems in reversed-phase (RP) separations, by judicious selection of the column and mobile phase conditions, are discussed....

There are two types of application for gas chromatography (GC) in the supercritical fluid extraction process. Gas chromatography is a type of supercritical extraction apparatuses which can separate a component from a multi-component mixture during supercritical extraction. Therefore, this application can be the alternative to conventional gas chromatography, which needs high temperatures for th...

When several plant hormones with similar structures are present in a sample, conventional analytical methods are not sufficiently selective to effectively differentiate them. However, the excellent selectivity of micellar liquid chromatography allows similarly structured compounds to be easily differentiated. We used reversed cholic acid micelles dissolved in tetrahydrofuran as the mobile phase...

background and objectives: a method was developed and validated for determining 15 polycyclic aromatic hydrocarbons (pahs) in refined olive and refined pomace olive oils using high performance liquid chromatography coupled with a fluorescence detector. materials and methods: the sample preparation involved liquid–liquid extraction with organic solvent and low temperature clean-up. the low tempe...

A retention prediction model was developed for peptides separated in reversed-phase chromatography. The model was utilized to identify and exclude the false positive (FP) peptide identifications obtained via database search. The selected database included human proteins, as well as decoy sequences of random proteins. The FP peptide detection rate was defined either as number of retention time o...

A reversed-phase salt assisted liquid-liquid extraction (RP-SALLE) method was developed for the preconcentration and determination of trace crocin in herbal medicines by high-performance liquid chromatography (HPLC). In developed method, the roles of the aqueous and organic phases are inverted so that the analyte is extracted from the organic into the aqueous phase after salt addition and phase...

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...