Определение йода в кормах и кормовых добавках методом вольтамперометрии
| Parent link: | Достижения науки и техники АПК.— , 1987- № 11.— 2011.— [С. 42-44] |
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| Other Authors: | , , , , |
| Summary: | Заглавие с экрана Проведены исследования по разработке методики определения йода в кормах и кормовых добавках методом вольтамперометрии (ВА) на органомодифицированном электроде (ОМЭ). The purpose of work consists in development of a technique of definition of iodine in forages and fodder additives method voltammetry (VA) on organo-modified electrodes (OME). It is investigated voltammetric behaviour of iodine - ions on silver electrodes modified by salts aryl diazonium tosylate with various groups of substituents: carboxy - (MAgE - СООН), amino - (MAgE - NH2) and nitro - (MAgE - NO2) put on a silver substrate. At comparison the calibration dependences of analytical signals of the iodine-ions received on modified electrodes, it is shown, that the electrode modified by aryl diazonium tosylate with an amino group as the assistant has the maximal sensitivity. This electrode has been used in the further work possesses. The main parameters of VA was selected - definitions of iodine-ions on OME are chosen: the time of electrolysis, the accumulation potentials, the nature of the supporting electrolyte, etc. The studies found that the determination of iodide ions at this electrode in the selected conditions do not interfere with the following elements: Zn, Co, Ni, Pb, Cu, Hg, Fe, As and Cd, whose presence is possible in feed and feed additives. The proposed method of voltammetric determination of iodide ions on the OME allows to reduce the number of used reagents, eliminate mercury, as well as to perform measurements in the presence of dissolved oxygen. At the stage of sample preparation of analyzed objects, for elimination of preventing influence of organic substances of a matrix and translation of all forms of iodine in the electroactive form - iodine- ions, alkaline fusion used. On the basis of the received results the algorithm of a technique of the quantitative chemical analysis of forages and fodder additives on the maintenance{contents} of iodine by method VA which is based on translation from test in a solution of all forms of iodine as iodine-ions, with the subsequent voltammetric definition on OME is offered. Thus accumulation of iodine-ions in a mixed solution carried out during 10-20 with electrolisys potential (0,0 ± 0,05) volt respect to the background electrodes silver chloride 0.1 mol/dm3 solution N2H4- H2SO4 followed by registration of cathodic peaks in the differential - pulsed voltammograms taken at scanning rate potential of 20 mV / sec. The concentration of iodide ions was determined using the highest peak in the range of potentials (- 0,4 ± 0,05) volt by the method of additives certified mixtures. A method for producing an analytical signal of iodide ions and the algorithm method of quantitative chemical analysis can determine the mass concentration of iodine by voltammetry in feed and feed additives within the 0,002 - 200 mg / kg with the relative standard deviation less than 20%. The correctness inspection of methodical data is carried out using the method "put - found", doubling weighed portion and comparing with State standard of the Russian Federation 52689-2006. Режим доступа: по договору с организацией-держателем ресурса |
| Published: |
2011
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| Subjects: | |
| Online Access: | http://elibrary.ru/item.asp?id=17067632 |
| Format: | Electronic Book Chapter |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=654680 |