Search results for "Bendroflumethiazide"
showing 8 items of 8 documents
Chromatographic monitoring of diuretics in urine samples using a sodium dodecyl sulphate—propanol micellar eluent
1994
Abstract The effect of a varying pH, in the range 3−7, on the retention of several diuretics eluted with a sodium dodecyl sulphate (SDS) micellar mobile phase and with UV detection was studied. Significant changes in the capacity factors ( K′ of the diuretics bumetanide, ethacrynic acid, furosemide, probenecid and xipamide were observed. The protonation constants of these compounds were calculated from the k′ data. A study was also performed to select the optimum composition of the mobile phase (pH, concentration of SDS and nature and concentration of alcohol) for the separation of the above diuretics and the diuretics amiloride, bendroflumethiazide, chlorthalidone, hydrochlorothiazide, spi…
Analysis of Urine Samples Containing Cardiovascular Drugs by Micellar Liquid Chromatography with Fluorimetric Detection
1999
A simple direct injection chromatographic procedure with fluorimetric detection is successfully applied to the determination of mixtures of 4 diuretics (amiloride, bendroflumethiazide, piretanide, and triamterene) and 6 beta-blockers (acebutolol, atenolol, labetalol, metoprolol, nadolol, and propranolol), which are usually administered in combinations for the treatment of hypertension, in urine samples. The procedure makes use of C18 columns and micellar mobile phases of sodium dodecyl sulphate (SDS), propanol, and phosphate buffer at pH 3. The adequate resolution of most drugs is obtained with a chemometrics approach where the retention is modeled as a first step using the retention factor…
FI-chemiluminometric study of thiazides by on-line photochemical reaction
2004
The present manuscript deals with a simple and sensitive flow-injection method for the chemiluminescent determination of thiazides. The method is based on the on-line photodegradation and chemiluminescent determination of the resulting photo-fragments. The on-line photodegradation is performed in basic medium by using a photoreactor consisting of a 550 cm long x 0.8 mm ID piece of PTFE tubing helically coiled around an 8 W low-pressure mercury lamp. The determination of the photo-irradiated thiazides is performed by a chemiluminescent oxidative reaction with Ce(IV) in sulphuric acid medium. A heterogeneous group of thiazides (indapamide, metolazone, hydroflumethiazide, chlorthalidone and be…
Chromatographic determination of diuretics in urine samples using hybrid micellar mobile phases with fluorimetric detection
1998
Abstract A rapid and simple chromatographic procedure, that uses hybrid micellar mobile phases of sodium dodecyl sulphate (SDS), propanol and phosphate buffer at pH 3, and fluorimetric detection ( λ exc =270 nm, λ em =430 nm), is reported for the determination of mixtures of seven diuretics of diverse efficacy (amiloride, bendroflumethiazide, bumetanide, furosemide, hydroflumethiazide, piretanide and triamterene), in urine samples. The application of a sequential optimization procedure for the resolution of the mixtures of the diuretics was problematic. However, their separation was achieved through the use of an interpretive optimization procedure based on the accurate description of the r…
Performance of micellar mobile phases in reversed-phase chromatography for the analysis of pharmaceuticals containing beta-blockers and other antihyp…
1996
A rapid and simple reversed-phase micellar liquid chromatographic procedure for the simultaneous determination of the beta-blockers atenolol, metoprolol and oxprenolol, the diuretics amiloride, bendroflumethiazide, chlorthalidone and hydrochlorothiazide and the vasodilator hydralazine in pharmaceuticals, is proposed. An interpretive optimization procedure, which uses the chromatographic data for only five mobile phases, was applied to select a suitable micellar mobile phase. A comparative study was also made of the performance of micellar and aqueous-organic mobile phases in the analysis of pharmaceuticals that combine beta-blockers and diuretics. The determination of all the drugs could be…
High-performance liquid chromatographic determination of diuretics in urine by micellar liquid chromatography.
1992
The use of micellar liquid chromatography for the determination of diuretics in urine by direct injection of the sample into the chromatographic system is discussed. The retention of the urine matrix at the beginning of the chromatograms was observed for different sodium dodecyl sulphate (SDS) mobile phases. The eluent strengths of a hybrid SDS-methanol micellar mobile phase for several diuretics were compared and related to the stationary phase/water partition coefficient with a purely micellar mobile phase. The urine band was appreciably narrower with a mobile phase of 0.05 M SDS-5% methanol (v/v) at 50 degrees C (pH 6.9). With this mobile phase the determination of bendroflumethiazide an…
Effects of pH and the presence of micelles on the resolution of diuretics by reversed-phase liquid chromatography
2004
A comparative study on the performance of two RPLC modes on the separation of 18 diuretics with diverse acid-base behaviour (acetazolamide, althiazide, amiloride, bendroflumethiazide, benzthiazide, bumetanide, canrenoic acid, chlorothiazide, chlorthalidone, ethacrynic acid, furosemide, hydrochlorothiazide, piretanide, probenecid, spironolactone, triamterene, trichloromethiazide and xipamide) was carried out. A conventional octadecylsilane column and acidic acetonitrile-water mobile phases, in the absence and presence of micelles of the anionic surfactant sodium dodecyl sulphate (SDS), were used. The effects of pH and the modifiers acetonitrile and SDS on peak asymmetry, efficiency, selectiv…
Micellar liquid Chromatographic determination of diuretics by diazotization and coupling with the Bratton-Marshall reagent
1997
Abstract A Chromatographic procedure that uses micellar mobile phases of sodium dodecyl sulphate (SDS) and propanol at pH 3 is reported for the determination, in urine samples, of thiazide diuretics (althiazide, bendroflumethiazide, chlorothiazide, hydrochlorothiazide, hydroflumethiazide, and trichloromethiazide), and other diuretics having a sulphonamide substituent in the benzene ring. Precolumn derivatization with sodium nitrite and N -(1-naphthyl)ethylenediamine, to form the coloured azo dyes of the hydrolyzed diuretics, decreased the polarity of the compounds and, consequently, their retention in the micellar eluents, and permitted detection in the visible region, eliminating thus the …