Showing papers on "Potassium iodate published in 1987"
TL;DR: A flow injection amperometric method is recommended for the iodimetric determination of sulphite in this article, where both the formation of iodine and its reaction with sulphite are carried out on-line in a single channel manifold consisting typically of 3 m of 0.71 mm bore transmission tubing.
Abstract: A flow injection amperometric method is recommended for the iodimetric determination of sulphite. Both the formation of iodine and its reaction with sulphite are carried out on-line in a single channel manifold consisting typically of 3 m of 0.71 mm bore transmission tubing. Iodine is formed reproducibly in the reverse FIA manner in an injected bolus of dilute acid using a slightly alkaline potassium iodate eluent containing an excess of potassium iodide, and is monitored at a glassy carbon electrode held at –0.2 V vs. SCE, without interference from dissolved molecular oxygen. When acidified sulphite standards or samples are injected into the same eluent a decreased iodine signal is obtained owing to the reaction of the sulphite injected with an equivalent amount of iodine. The decrease in signal size is rectilinear with the sulphite concentration of the injected solution in the range 0.1 × 10–4–4 × 10–4M when injection is made into an eluent 3 × 10–5M in potassium iodate and 0.1 M in potassium iodide.Methods of determining sulphite in which the reaction between iodine or bromine and sulphite is carried out off-line and the excess of iodine or bromine is determined amperometrically by injecting the reacted solution into an inert iodide or bromide eluent, or in which a slightly alkaline sample solution containing iodate-iodide is injected into an acidic eluent, have also been developed.
14 citations
TL;DR: A simple colorimetric procedure is described for determination of penicillin G salt and penicillamine, which proved to be more rapid, highly reproducible and reasonably accurate.
Abstract: A simple colorimetric procedure is described for determination of penicillin G salt and penicillamine. It is based on oxidation with potassium iodate at room temperature and measurement of the liberated iodine at 520 nm after extraction with carbon tetrachloride. Compared with other procedures, this method proved to be more rapid, highly reproducible and reasonably accurate. The relative standard deviation did not exceed 0.9% and 0.4% for penicillin and penicillamine, respectively. The procedure has been successfully applied to pharmaceutical preparations containing either of the two compounds.
10 citations
01 Oct 1987
TL;DR: In this paper, the influence of the potassium iodate concentration on the hydrogen peroxide decomposition in the Bray-Liebhafsky reaction is analyzed by the kinetic observations described in previous publication.
Abstract: The influence of the potassium iodate concentration on the hydrogen peroxide decomposition in the Bray-Liebhafsky reaction is analysed by the kinetic observations described in our previous publication [1]. The overall decomposition of hydrogen peroxide in the presence of KIO3 and H2SO4 is found to follow the first order kinetics, not only with respect to hydrogen peroxide, but also with respect to potassium iodate. The rate constant of the process is evaluated.
10 citations
TL;DR: A spray reagent for their detection in biological materials by thin-layer chromatography is described, which has no interference from other organochloro insecticides or even carbamate insecticide or from the constituents of visceral extracts.
Abstract: The misuse of sulphur-containing organophosphorus insecticides results in many instances of poisoning. This paper describes a spray reagent for their detection in biological materials by thin-layer chromatography. Sulphur-containing organophosphorus insecticides react with acidified potassium iodate liberating free iodine, which in turn reacts with starch solution to give a blue colour. In alkaline media the colour is intensified and consequently the sensitivity of detection increases. There is no interference from other organochloro insecticides or even carbamate insecticides or from the constituents of visceral extracts (amino acids, peptides, proteins, etc). The limit of detection is ca. 1 µg.
10 citations
TL;DR: In this article, the time needed for a 40mV potential change is inversely proportional to concentration, and selectivity is improved by sweeping the sulphur dioxide formed in acidic EDTA-containing solution into the iodate solution.
4 citations
Journal Article•
TL;DR: By regional and countrywide studies carried out in the past 10 years the occurrence of endemic goitre and iodine deficiency (ID) of grade II has been demonstrated in 1981 and the persistence of iodine deficiency ofgrade II has yet to be stated by low renal iodine excretion, low iodine content of milk and human milk post partum.
Abstract: By regional and countrywide studies carried out in the past 10 years the occurrence of endemic goitre and iodine deficiency (ID) of grade II has been demonstrated in 1981. In 1983 till 1985 an iodized salt (25 mg KI/kg) was offered mainly in the southern counties of the G.D.R. This measure has been followed by the production of 84% of the whole paket salt iodized with stable potassium iodate (32 mg KIO3/kg) since July 1985 and delivered in all the G.D.R. Nevertheless, in the end of 1985 the persistence of iodine deficiency of grade II has yet to be stated by low renal iodine excretion, low iodine content of milk and human milk post partum. The reference values of TT3 (0.84-3.76 nmol/l) and TT4 (41.8-137.3 nmol/l) assessed in 1985 for the G.D.R. are to be interpreted before the background of an iodine deficiency of grade II.
2 citations
TL;DR: In this article, the authors carried out bifurcation analysis of its mathematical model and determined the criteria for the appearance and size of the limit cycle in the phase space of the concentrations of the basic variables of the system.
Abstract: In order to determine the sufficient conditions for realization of oscillatory instability and the stages responsible for destabilization of the reaction regime in the potassium iodate-hydrogen peroxide-cysteine-sulfuric acid system, we have carried out bifurcation analysis of its mathematical model. We have determined the criteria for the appearance and size of the limit cycle in the phase space of the concentrations of the basic variables of the system; we have established the number and type of stability of the stationary states.