CS239535B1 - Method for determination of active chlorine content in hypochlorite and chloramine solutions - Google Patents

Abstract

In the proposed method of determination, a solution of chloramines or hypochlorite with free chlorine is introduced into a solution consisting of 10"^ to 10-4 mol.l"! chromium sulfate with 2 to 0.1 mol.l"! potassium bromide in 5 to 0.1.1"! inorganic acid, the change in potential is measured using a platinum electrode. The determination according to the above solution can find application in the analysis of hypochlorites, chloramines and their mixtures in the textile industry, in medicine and in the military field.

Description

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KELLNER JOSEF ing.CSc., VYŠKOV, * PSlKRYL FRANTISEK prof.ing.CSc., BRNO; HALÍMEK EMIL doc.ing.CSc.J

SOUČEK JAN ŘNDr.CSc., VYŠKOV; grmel believe that the desired mountain

Method for determination of active chlorine content in hypochlorite and chloramine solutions

In the proposed method of determination, a solution of chloramines or hypochlorite with free chlorine is introduced into a solution of 10 -4 to 10 -4 mol.l -1! chromium sulfate with 2 to 0.1 mol.l ”! of potassium bromide in 5 to 0.1.1 ”! Inorganic acid, the potential change is measured using a specific platinum electrode. The determination according to said solution can find application in the analysis of hypochlorites, chloramines and their mixtures in the textile industry, in medicine and in the military field.

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239 S3S

The invention solves the determination of active chlorine content in hypochlorite and chloramine solutions by direct potentiometry.

Chloramines and hypochlorites are used in analytical chemistry, in the textile industry, in the military field, and in medicine (Afanasjev, B.N .: Usledchi chimii, 21, 69, 1952). Their oxidation and chlorination effects are used here. Most authors attribute the oxidative effects of these compounds to hypochlorous acid (Komarovskij, A.S .; Filonova, V.F .; Korenman, J.M .:

OF. prikl. chim. 6, 742 (1933); Poethke, W .; Wolf, F .: Z. anorg. und.allg. Chem., 268, 244, 1952). Others assume oxidation due to the release of atomic oxygen or free halogen (Bishop, E .; Jennings, V.J .: Talanta, 1, 197, 1958; Bishop, E. Jennings, V.J .: Talanta, 8, 22, 1961).

In practice, iodometric titration or titration using arsenite or hydrazine sulfate is used to determine the active chlorine content of hypochlorite and chloramine solutions (Narkus, PK; Prokopčík, AJ: Ž. Analit. Chim., 16, 323, 1961) . These classical assays are very lengthy and chemical-intensive.

The above drawbacks are eliminated by the method of the invention, which is based on the method of determining the active chlorine content of hypochlorite and chloramine solutions by direct potentiometry, wherein a solution of hypochlorite or chloramines with free chlorine is introduced into a solution of chromium sulphate and potassium bromide in sulfuric acid. potential is measured using a specific platinum electrode. Under these conditions, the oxidative effects of active chlorine from both hypochlorites and chloramines are equally quantifiable.

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The construction according to the invention is fast, simple and accurate, particularly suitable for series analysis.

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Example 1 ^w 3 * · 1

From the basic solution of chromium sulphate 10 mol.l 1 mol.l ^J 'of potassium bromide in 1 mol.l ^"1 sulfuric acid were metered 15 ml into a 50 ml beaker. A pair of electrodes, a shiny platinum electrode, rinsed in concentrated sulfuric acid) and distilled water, and a saturated calomel electrode, were immersed in the solution.

The solution was then pipetted with 1 ml of a chloramine solution with a measured content of active chlorine. The electromotive force of the galvanic cell was measured and the active chlorine content was read from the calibration graph. A calibration graph showing the dependence of the platinum electrode potential on the active chlorine content of the solution was obtained by measuring a set of calcium hypochlorite solutions standardized by the iodometric titration method. The relative determination error achieved in the range of 0.5 to 0.01 percent active chlorine concentrations did not exceed 3 percent.

Example 2

The sensitivity of the assay can be increased by adjusting the workflow. The determination was carried out as in Example 1, only the base solution was measured with 10 ml into a 50 ml beaker and 10 ml of a hypochlorite solution with a measured content of active chlorine was pipetted into this solution. The relative determination error achieved in the concentration range 0.05 to 0.001 percent active chlorine did not exceed 5 percent.

Example 3

The assay was performed as in Example 1. However, a mixture of hypochlorite and chloramine was pipetted. The relative determination error did not exceed 3 percent, as in Example 1.

Claims (1)

SUBJECT OF THE INVENTION 239 53S Method for determining the content of active chlorine in solutions of hypochlorites and chloramines by direct potentiometry, characterized in that the analyzed solution of hypochlorites or chloramines with free chlorine is introduced into a solution consisting of 10 to 10 moles of chromium sulphate with 2 to 0.1 moles * Potassium bromide in 5 to 0.1 inorganic acid, for example sulfuric acid, and the potential change is measured using a specific platinum electrode.