A rapid, reliable and accurate method for the determination of hexavalent chromium in Portland cement is developed. The proposed method includes direct spectrophotometric determination of Cr (VI) in Portland cement with 1, 2, 5, 8 Tetrahydroxyanthraquinone, (Quinalizarin, QINZ) at pH 1.5. The European Directive (2003/53/EC) limits the use of cements so that it contains no more than 2 mg·Kg of w...

IN1934 SHOCK AND HASTINGS (1) described the construction and use of a micropipet, by means of which blood in 0.1 ml. aliquots could be used for the simultaneous determination of pH, 002 content, and red cell volume. In this method the blood in two pipets was diluted to 2.0 ml. with saline-phenol red solution, centrifuged, and used first for the determination of hematocrit value, second for the ...

The phenol photocatalytic degradation was investigated using heterogeneous catalyst Ag-doped ZnO nanowires under UV irradiation. Ag-ZnO nanowires were immobilized on borosilicate glass via a simple hydrothermal technique. Preliminary photodegradation studies were performed with Ag-ZnO nanowires at various concentrations of phenol (10 60 mg/L) at undiluted pH. After determination of the optimal ...

.he recent determination of the ocular temperature gradient indicated the necessity to define those ocular physiologic and metabolic functions, especially of the anterior segment of the eye, which are most temperature dependent. One such important function is that of pH or hydrogen ion activity of the anterior chamber aqueous humor. With the recent introduction of extremely stable pH meters as ...

A direct polarographic method for the determination of chlorpheniramine maleate in pharmaceutical preparations had been developed. The method was based on the reduction of chlorpheniramine maleate in an acidic medium (pH 1.2-4.0). The effect of pH on the polarographic wave was investigated by recording d.c. polarograms in various supporting electrolytes. The calibration graphs were rectilinear ...

A flow injection photometric method for the sequential determination of zinc and copper in mixtures was developed based on the variation of the stability of the chromogenic complexes between the analytes and the reagent zincon with pH. At pH 5.0 only the Cu-zincon complex exists, whereas at pH 9.0 the copper and zinc chelates co-exist. A three-channel manifold was implemented containing two alt...

The electrochemical behaviour of dimethyl-2-oxoglutarate (MOG), a key intermediate in the Krebs cycle and an important nitrogen transporter in the metabolic pathways in biological processes, was investigated by cyclic voltammetry, square wave voltammetry and differential pulse voltammetry using a glassy carbon electrode. The reduction of MOG is an irreversible diffusion-controlled process that ...

A simple and highly selective spectrophotometric method has been developed for the determination of trace amounts of V (V) using newly synthesized reagent 5-bromo salicylaldehyde isonicotinoyl hydrazone (5BrSAINH) in aqueous DMF medium. Vanadium (V) forms a brown colored soluble complex with 5-BrSAINH in the pH range 1.0-5.0. The complex shows maximum absorbance at 400nm in the pH range 4.5-5.5...

A simple and highly sensitive voltammetric method was developed for the determination of isoxsuprine HCl (I) and fenoterol HBr (II) in dosage forms and biological fluids. The method is based on treatment of the two compounds with nitrous acid followed by measuring the cathodic current produced by the resulting nitroso derivatives. The voltammetric behavior was studied adopting Direct Current (D...

the construction and performance of an amperometric microbiosensor for the determination of choline chloride by immobilizing choline oxidase on a cellulose acetate membrane are described. the procedure of choline determination involved the electrochemical detection of enzymatically generated hydrogen peroxide. this microsensor has a linear response between 0.038-0.1 mm choline chloride. the res...