SU834490A1 - Silver chlorine contact semi-component for glass electrode - Google Patents

Description

(54) CHLORINE-CONTACT SEMILEMENT FOR GLASS ELECTRODE

one

The invention relates to chemical and chemical analysis methods, in particular ionometry, and can be used to measure EMF in solutions with an extended: temperature range from 100 to 150 ° C.

Chloride-silver contact elements are known for working at high temperatures (higher), but they are labor-intensive and have a high content of precious metals such as platinum (Pt) and silver (Hell) 1.

The closest technical solution is a silver-chloride electrode, containing a platinum base and successively deposited layers of Hell and AgCl 2.

However, due to the porosity and unevenness of the silver chloride layer on. The surface of the blue wire at known electrodes shows adsorption, enhanced concentration, rational polarization and dissolution of silver chloride at temperature drops, which ultimately worsens metrological readings, affects the stability, sensitivity of the electrode and reproducibility.

The purpose of the invention is to expand the temperature operating range of the electrode. .

The goal is achieved by taking the basis of the Pt) Ag | AgCl additionally contains successively located on top of the AgCl layer SOL Ad and

The introduction of an additional layer of Hell into the element leads to the fact that the potential forming silver chloride coating is covered with a protective layer of silver sulfide (AddZ), which, extremely richly, has low solubility; 5 (Pr 5.7-10-) prevents the dissolution of chloride ra (Pr AgCl 210-) in the electrode solution. The silver coating of silver sulfide protects the Pt lAgl AgCl extending system from dissolution, thereby stabilizing the electrode potential, linearity, and measurement limits. The electrode acquires the ability to work in more

Claims (2)

5 iiImpoKOM temperature range I (100-150 0, which will allow you to create electrodes and devices for measuring SDS with a wide operating temperature range and higher accuracy and reliable results. current 0.2 A / dm), then sulfided from a solution containing 1.5 g / l of sodium sulfide and 5.85 g / l of sodium hydroxide for a period of 10 min (current density of 0.3 A / dM). Sulfidated / contact semi-maleutites are dried in .. closet for 1 h at t, then 2 h at t. The test of the quality of the obtained contact floor of the element is made by determining the potential value of 0.1 N. NaCl solution relative to the silver-chloride reference electrode (GOST 16286-76) at t The potential value is E - 86 ± 1 mV, which corresponds to T retically the calculated value of the potential of the systems Ad I AdSC C1 E Еr-In d (- - Е, nF where Ko is the standard electrode potential; is a gas constant; potential of the electrode Compared with the existing chlorine-silver contact half cell, the following advantages are provided: extending the operating temperature range of the electrode; stabilizing the values of the functional characteristics of the electrode; reducing the labor intensity of the production of electrodes; saving precious metals. deposited on the layers of Hell and AgCl, differing from the fact that, in order to expand the working rate Saturn band member further comprises a top layer successively disposed layers AgCl. Hell and,. Sources of information taken into account in the examination 1. Instructions WE. 1301.002, 1973, 2. Bates R. Determination of pH. Theory and practice. L., Khimi, 1968, Co 248-249 (prototype).