Catalytic/kinetic potentiometric determination of organic iodine-containing compounds

A kinetic method is described for the determination of microgram amounts of various organic iodine-containing compounds, based on their catalytic effect on the cerium (IV)/arsenic (III) reaction. The time required for a 15-mV change in potential is inversely proportional to the compound concentration

Catalytic/kinetic potentiometric determination of organic iodine-containing compounds

A kinetic method is described for the determination of microgram amounts of various organic iodine-containing compounds, based on their catalytic effect on the cerium(IV)/arsenic(III) reaction. The time required for a 15-mV change in potential is inversely proportional to the compound concentration. © 1988

Catalytic/kinetic potentiometric determination of organic iodine-containing compounds

A kinetic method is described for the determination of microgram amounts of various organic iodine-containing compounds, based on their catalytic effect on the cerium (IV)/arsenic (III) reaction. The time required for a 15-mV change in potential is inversely proportional to the compound concentration

Kinetic-Potentiometric determination of ascorbic acid, biotin, pyridoxine hydrochloride and thiamine hydrochloride with N-bromosuccinimide

A kinetic-potenitometric method is proposed for the determination of ascorbic acid, biotin, pyridoxine hydrochloride and thiamine hydrochloride. The vitamin reacts with N-bromosuccinimide and the rate of production of bromide is monitored with a bromide-selective electrode. The method is simple, reliable and relatively free from interferences from common excipients and coexisting vitamins when applied to tablets and injections. The results obtained for the assay of commercial pharmaceutical preparations compare well with those obtained by official chemical methods and demonstrate good accuracy and precision. © 1989

Chemiluminescence determination of tetracyclines via aluminum sensitized fluorescence

Tetracycline, oxytetracycline, doxycycline, and chlortetracycline have been determined by chemiexcitation of the corresponding Al(III) highly fluorescent complex from the permanganate or cerium(IV)-sulphite chemiluminogenic reactions. Limits of detection and ranges of linearity are equal to 0.024, 0.015, 0.014, and 0.050 μg mL-1 and 0.067-3.20, 0.042-1.70, 0.042-3.00, and 0.103-2.80 μg mL-1 for tetracycline, oxytetracycline, doxycycline, and chlortetracycline, respectively. Average recovery of tetracyclines from solutions of commercial formulations was equal to 99.8% and the procedure was successfully applied to the determination of tetracyclines in commercial products with mean relative error equal to 3.4% (range 1.4-5.0%). © Taylor & Francis Group, LLC

Kinetic-Potentiometric determination of ascorbic acid, biotin, pyridoxine hydrochloride and thiamine hydrochloride with N-bromosuccinimide

A kinetic-potenitometric method is proposed for the determination of ascorbic acid, biotin, pyridoxine hydrochloride and thiamine hydrochloride. The vitamin reacts with N-bromosuccinimide and the rate of production of bromide is monitored with a bromide-selective electrode. The method is simple, reliable and relatively free from interferences from common excipients and coexisting vitamins when applied to tablets and injections. The results obtained for the assay of commercial pharmaceutical preparations compare well with those obtained by official chemical methods and demonstrate good accuracy and precision. © 1989

Determination of reducing sugars with a 2,4-dinitrophenolate-selective membrane electrode

A 2,4-dinitrophenolate-selective liquid-membrane electrode based on tetrapentylammonium dinitrophenolate dissolved in 2-nitrotoluene is described. The electrode exhibits rapid and near- Nernstian response to the activity of 2,4-dinitrophenolate anions in the range 3×10-5 -1×10-2 M. The response is unaffected by pH in the range 7.5-12.5. The electrode has been successfully applied to the kinetic potentiometric determination of fructose, glucose and galactose at 60°C and of fructose in the presence of glucose and galactose at 30°C. The electrode can be used for the potentiometric determination of glucose and fructose after completion of the reaction with excess of 2,4-dinitrophenolate ions and of sucrose after acid hydrolysis. Mixtures of glucose, fructose and sucrose in aqueous solutions or honey samples can be determined by the proposed procedures with an average error of about 2%. © 1989