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...

Thwaites and Pine Island Glaciers as well other ice streams in West Antarctica have been changing dramatically over the past decades. Although changes ocean conditions are likely primary driver of these changes, it remains unclear where processes could cause more mass loss. By employing Automatic Differentiation two independent ice-sheet models, we construct maps sensitivity volume above floata...

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 ...

the net analyte signal standard addition method was used for simultaneous spectrophotometric determination of sertraline and fluoxetine in pharmaceutical preparations. the method combines the advantages of the standard addition method with the net analyte signal concept to enable the extraction of information about an analyte from the spectra of multi-component mixtures. this method uses full s...

a simple, selective and sensitive method for the determination of trace amount of titanium (iv) based on its catalytic effect on methylene blue- ascorbic acid redox reaction has been reported. the reaction was followed spectrophotometrically by measuring the change in absorbance of methylene blue at 665 nm, 5 minutes after the initiation of the reaction. in this study experimental parameters we...