SU1567934A1 - Spectrophotometric method of determining nickel - Google Patents

Abstract

This invention relates to analytical chemistry, and specifically to methods for determining nickel in steels, alloys, and other materials that do not contain cobalt. The aim of the invention is to increase the selectivity and expressivity of nickel determination in a wide range of concentrations. The method includes preparing a solution of the nickel complex with ethylenediaminetetraacetic acid at PH 4.5, .. 6.8, photometric measurement at a wavelength of 1000 ... 1100 nm. Copper is precipitated with sodium diethyldithiocarbamate in the presence of lead ethylene diamine tetraacetate, the concentration of which is chosen depending on the copper content. 2 hp ff, 2 tab.

Description

The invention relates to analytical chemistry, in particular to methods for determining nickel in steels, alloys and other materials that do not contain cobalt, and can be used in processing technology and analysis of ores, metallurgy and other areas of national economy.

The purpose of the invention is to increase the selectivity and expressivity of the method.

Example 1. Analysis of steels with a nickel content of 0.5-3.0%.

A weight of 0.5 g of steel was dissolved in 20-25 ml of 1: 1 hydrochloric acid, oxidized with nitric acid. The solution was evaporated to a syrupy state, 5 ml of hydrochloric acid was diluted 1: 1, and evaporated to syrupy state. Then 10-15 ml of hydrochloric acid diluted 1:10 are poured. 50 ml of reaction mixture No. 1, Yu ml of 1.5% sodium diethyldithiocarbamate solution (when the copper content in the sample is more than 2% sodium diethyldithiocarbamate solution is introduced from

calculating 5 ml of solution for 1% copper) The volume of the solution is made up to 100 ml with water, filtered after 10 minutes and photometted on a spectrophotometer at a wavelength of 1055 nm Comparison solution — a solution of iron, corresponding to the iron content in the sample with an accuracy of ± 5%; through the course of the analysis The nickel content is found according to a schedule or two standard samples of an appropriate composition, carried out through the course of the analysis. All elements, except cobalt, are not interfered with in any quantities.

Irin; 2 An, 1 or 1 steel with a nickel content of l - 2%.

The determination is carried out analogously to example 1 with the following changes: weighed 0.2–0.5 g; in the analysis of steels with a copper content less than 0.1%, the reaction buffer mixture L1 2 is used; do not enter diethyldithiocarbamate sodium

Example 3. Analysis of steels with a nickel content of 10–30%.

ate

oe 1

with

wasp

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Determination as in Example 2. A solution of a standard sample sample and a .1 and a hereditary mixture with a nicot content 5-10% lower than in the analyzed sample is used as a comparison solution.

Example 4 Analysis of aluminum alloys with a nickel content of 0.5-3%

A 0.5 weight weight of the alloy was dissolved without heating in 15 ml of hydrochloric acid, diluted with G1, oxidized without heating with nitric acid or peroxide in sodium. The resulting solution was made up to boiling. 1.5% sodium diethyldithiocarbamate solution at the rate of 5 ml of solution per 1% of copper, volume of solution T. O water of 100 ml, filtered after 10 minutes and photometrized at 1055 nm

(opav reactionary buffer iM se, g / l

No. 1 Vinegar no-sour.

ammonium200

Disodium salt of ethylene bottom of tetra-acetic acid kita (tri-Jun b) 100

Acetic acid swee

Note D, - allowable discrepancies between the results of parallel determinations; D is the allowable discrepancy between the results of the first and repeated measurements of the nickel content in the analyzed sample; P is the permissible deviation of the measurement result of nickel in the standard sample from the certified value, Srcx is the guaranteed value of the convergence indicator of parallel determinations, Cr. - guaranteed value of the indicator of reproducibility of measurements, Art - guaranteed value of the indicator of correctness of measurements

Claims (1)

Invention Formula five 0 0 5 2 1A spectrophotometric method for determining nickel, which consists in transferring a sample to a solution, introducing ethylenediamine tetraacetic acid into the solution at pH 4.5-6.8 and measuring the optical density of the solution in the absorption band of the resulting compound, in order to increase the selectivity and expressiveness method, the optical density is measured in the wavelength range of 1000-1100 nm 2 Method 1, characterized in that, in order to ensure that samples containing 0.1 to 2% copper were known, before measuring the optical density, ethylenediaminetetraacetate of lead was introduced into the solution in an amount of 2 to 5 masses and a sample of sodium nitate in the amount of 1 -4 mass of sample and filtered solution 3 Method according to claim 1, wherein That, the L chain for analyzing samples containing more than 2% copper, before measuring the optical density, enine sodium diamine tetraacetate of lead is added in a mixture of 2 to 5 mass of sample weight and sodium dithiocarbamate at the rate of 15 mg per 1 mg of copper and the solution is filtered