phase together with a counterion. Schurig V (1984) Gas chromatographic separation of enantiomers on optically active stationary phases. Angewarde Chemie International Edition English 23: 747}765. Schurig V (1994) Enantiomer separation by gas chromatography on chiral stationary phases. Journal of Chromatography 666: 111}129. Schurig V and Nowotny H-P (1990) Gas chromatographic separation of enan...

clonidine hydrochloride is an antihypertensive agent used for migraine prophylaxis, attention deficit hyperactivity disorder, menopausal flushing and tourette syndrome. the quantity of the active substance in pharmaceutical preparations must be within specific limits, in agreement with the respective label claim. therefore, the aim of this study was to establish the conditions for two spectroph...

Three rapid spectrophotometric methods were developed for the determination of sunitinib based on the formation of ion-pair complex in acidic medium with bromocresol purple, bromothymol blue, and bromophenol blue. The formed ion-pair complexes, extractable with chloroform, were measured at 422 nm for bromocresol purple, 425 nm for bromothymol blue and 427 nm for bromophenol blue. All these meth...

The interactions between an anionic dye, Acid Green 25 AG and the two cationic surfactants tetradecyltrimethylammonium bromide TTAB, and hexadecyltrimethylammonium bromide CTAB in aqueous solutions far below the CMC are studied using the conductometric method at different temperature. The equilibrium constants and other thermodynamic functions for the process of dye-surfactant ion pair formatio...

Three rapid spectrophotometric methods were developed for the determination of sunitinib based on the formation of ion-pair complex in acidic medium with bromocresol purple, bromothymol blue, and bromophenol blue. The formed ion-pair complexes, extractable with chloroform, were measured at 422 nm for bromocresol purple, 425 nm for bromothymol blue and 427 nm for bromophenol blue. All these meth...

In this study a sensitive, simple and accurate spectrophotometric method was suggested for determination of tamsulosin in bulk powder and pharmaceutical dosage form based on the formation of an ion-pair complex between the drug and bromocresol green in a buffer solution at pH 3.5. The formed yellow color complex was extracted with chloroform and measured at 415 nm. The optimum reaction conditio...

In this study a sensitive, simple and accurate spectrophotometric method was suggested for determination of tamsulosin in bulk powder and pharmaceutical dosage form based on the formation of an ion-pair complex between the drug and bromocresol green in a buffer solution at pH 3.5. The formed yellow color complex was extracted with chloroform and measured at 415 nm. The optimum reaction conditio...