In this study, a high-performance liquid chromatographic method (HPLC) and UV spectrophotometric method were developed, validated and applied for the determination of theophylline in biological fluids. Liquid- liquid extraction is performed for isolation of the drug and elimination of plasma and saliva interferences. Urine samples were applied without any extraction. The chromatographic separat...

PURPOSE This study was designed to develop and validate two simple, rapid, and economical UV-spectrophotometric and the first-order derivative methods using the area under curve method for estimation of diacerein in bulk and in capsule formulation. MATERIALS AND METHODS In this study, hydrotrophic solution of 8 M urea and 0.5 M potassium citrate were employed as the solubilizing agent to solu...

The present work describes a new HPLC method and a new spectrophotometric method for the simultaneous determination of ethinyl estradiol (EE) and levonorgestrel (LNG) in their binary combination. In LC method, Nucleosil C8 column with a mobile phase composed of acetonitrile-water (90:10, v/v) with UV detection at 225 nm were used for the analysis of ethinyl estradiol-levonorgestrel combination....

Eumelanin (brown/black melanin) and pheomelanin (red/yellow melanin) in human hair can be quantified using chemical methods or approximated using spectrophotometric methods. Chemical methods consume greater resources, making them less attractive for epidemiological studies. This investigation sought to identify the spectrophotometric measures that best explain the light-dark continuum of hair c...

New simple and sensitive spectrophotometric and fluorimetric methods have been developed and validated for the determination of fluoxetine hydrochloride (FLX) in its pharmaceutical formulations. The spectrophotometric method was based on the reaction of FLX with 1,2-naphthoquinone-4-sulphonate (NQS) in an alkaline medium (pH 11) to form an orange-colored product that was measured at 490 nm. The...

UNLABELLED In this study, a high-performance liquid chromatographic method (HPLC) and UV spectrophotometric method were developed, validated and applied for the determination of theophylline in biological fluids. Liquid- liquid extraction is performed for isolation of the drug and elimination of plasma and saliva interferences. Urine samples were applied without any extraction. The chromatograp...

The glass surface modification with 3-(mercaptopropyl) trimethoxysilane (MPTS), gold nano-particles (GN) and guanine rich single strand DNA (ss-DNA) was utilized as a novel and efficient platform for sensing trace concentration of methylene blue (MB) by an inexpensive spectrophotometric method. Methylene Blue (MB) can interact with the guanine base of single strand DNA and absorbed onto glass s...

Recently solution scanometry, as a new, simple, fast, portable, and economic method was introduced for determination of acidity constants of indicator and dyes. In this study, a method was applied for the determination of the acidity constant of p-Rosolic acid (RA) and Bromoxylenol blue (BXB) indicators. The method is based on scanning of Plexiglas® sheet containing colored solutions with a fla...

A new assay for 3-hydroxy-3-methylglutaryl CoA reductase (mevalonate: NADP oxidoreductase [acylating CoA] , EC 1.1.1.34) is based upon the measurement of released coenzyme A (SH) during the reduction of 3-hydroxy-3-methylglutaryl CoA to mevalonate. Coenzyme A was measured in the presence of dithiothreitol, required for activity, by reaction with 5,5’-dithiobis(2-nitrobenzoic acid). Sodium arsen...

In a previous publication (1) from this laboratory, it was demonstrated that the transamination of amino acids to a-ketoglutaric acid is a reaction of wide scope. Although the data reported in the earlier paper permitted the computation of Q transaminase values, these values were of limited quantitative significance since no attempt was made to study the kinetics of these reaction systems, the ...