A simple and reproducible HPLC method with spectrophotometric detection was developed for determination of rivastigmine in human plasma. Liquid-liquid extraction of rivastigmine and donepezil (as internal standard) from plasma samples was performed with 1-butanol/n-hexane (2:98 v/v) in alkaline condition followed by back-extraction into diluted acetic acid. Chromatography was carried out using ...

We describe a simple, sensitive, and specific high-performance liquid-chromatographic method with ultraviolet detection (256 nm) for the simultaneous analysis of nicotine and cotinine in urine of passive smokers. The analytes are extracted and purified from the complex and impure matrix in two stages; first, by liquid-liquid extraction and followed by solid-phase extraction (C2 column). We used...

Microwave-assisted extraction was applied to extract rutin; quercetin; genistein; kaempferol; and isorhamnetin from Flos Sophorae Immaturus. Six independent variables; namely; solvent type; particle size; extraction frequency; liquid-to-solid ratio; microwave power; and extraction time were examined. Response surface methodology using a central composite design was employed to optimize experime...

the occurrence and fate of trace-level contamination of pharmaceuticals in the aquatic environment has been recognized as one of the emerging issues in environmental chemistry. the effluents of wastewater treatment plants, usually directly emitted to the environment, often contain the anti-inflammatory drug diclofenac. diclofenac was chosen because it is of high consumption; by background liter...

A reversed-phase high-performance liquid chromatography method using evaporative light-scattering detection is developed for the determination of residual octylglucoside (OG) levels after a detergent exchange step for in-process samples of a vaccine antigen. The reversed-phase column not only provides separation of the OG but also functions as an extraction column to remove the vaccine antigen ...

a convenient liquid chromatographic-single quadrupole mass spectrometric (lc-ms) method was developed and validated for dexchlorpheniramine maleate (inn name: chlorphenamine) determination in human plasma. the need for just a single liquid-liquid extraction with ethyl acetate and being highly sensitive were the advantages of this method. the linearity was also excellent over the range of 1 to 1...

membrane assisted liquid extraction(male) technologies are gaining an important role as an extraction /separation technique for actinides and are being deployed as a  promising tool for remediation of nuclear waste generated in the reprocessing plant and other radioactive wastes containing a trace level of radionuclides. the present contribution outlines the classification of membrane assisted ...

The first semi-continuous Pressurized Liquid Extraction (PLE) of hemp threshing residue with ethanol was carried out according to a 32 full factorial experimental design pressure and temperature as independent variables at 8-10-12 MPa 323-333-343 K, respectively. total- cannabidiol (CBD) yield curves were fitted the modified two-parameter Brunner equation. Best results, concerning CBD, can be a...

A rapid, sensitive and selective analytical method was developed and validated for the determination of compound K, a major intestinal bacterial metabolite of ginsenosides in human plasma. Liquid-liquid extraction was used for sample preparation and analysis, followed by liquid chromatography tandem spectrometric analysis and an electrospray-ionization interface. Compound K was analyzed on a Ph...