SU1402913A1 - Composition of membrane of chalcogenid glass electrode for determining sodium ions - Google Patents

Abstract

The invention relates to physicochemical methods of analysis and is intended to determine the activity (concentration) of sodium ions in liquid media. The purpose of the invention is to increase the selectivity of the determination of Na ions in the presence of Ni ions to improve performance in fluoride media. The goal is achieved by using chalcogenide glass of the following composition as the membrane; mol.%: sodium chloride 5-30 gallium sulfite 5-35; Herma disulfide g nor 20-85; Germanium sulphide remaining. 2 tab. 1 il.)

Description

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The invention relates to physico-chemical analysis methods and is intended to determine the activity (concentration) of sodium ions in liquid media.

The purpose of the invention is to increase the selectivity of c. the presence of hydrogen ions and the improved performance of electrodes in fluoride media.

The drawing shows the electrode characteristic of the proposed electrode.

The resistivity of the glasses of these compositions does not exceed 107 Ohm.cm.

Example. To obtain a glass of composition 5 KaCl-10 Ca Z3 DZO GeS, - X 5 CeS in an amount of 5 g take the elementary Ga, Ge, S, NaCl in the amounts indicated for each specific example in Table. , placed in a quartz ampoule, vacuum and sealed. The synthesis is carried out at 1400 K for 3 hours.

The obtained ingots are cut into semi-parallel disks with a thickness of 1-5 mm, which are then polished and glued with epoxy in the polyvinyl chloride body of the electrode.,

For the measurement of electrode characteristics, apply the following electrochemical cell;

Ag, AgCl KCl, aJOJ M KNOji

.1 study “pa with TV op membrane 0.01 M NaCl I AgCl, Ag.

The caliber of h-solutions are prepared from catarc nitrate. Solutions containing 1: E. CG - 10 M are prepared directly in the measuring cell by adding to iz €; stnomz volume of distilled petrol / small quantities of ka.pibroEakiy of sodium nitrate solutions with For measuring the coefficients of the pure selectivity, the mixed solutions method is used, at which end; the antithesis of the interfering suit is kept constant, and the end.

they vary within

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10- M.

Iamerekie ZDS electrochemical cells 1 /. research; -. & w. t delivery was performed with a non-number, D. p.

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Mixing the solutions using a nitric stirrer.

It can be seen in the drawing that the electrodes under study have an electrode function of 45–47 mV / decade in the concentration range from 10 to 1 M and a lower limit for the detection of sodium ions, Z l O M. The reproducibility of the potential in a millimolar solution of sodium nitrate is 0.2-0.5 mV . Similar characteristics have a commercial sodium selective oxide electrode ESL-51G-04.

In tab. 2 presents the selectivity coefficients of the electrodes ,.

From Table 2, it can be seen that the 10,000-fold excess of alkaline-earth metal cations is 5 to 1,000-fold excess. Nickel ions do not interfere with the operation of the chalcogenide. glass electrodes. Alkaline cations have a stronger interfering effect.

Chalcogenide glass electrodes at C 5.5-10 show a function in the concentration range of 10 1 M sodium nitrate, while the oxide glass electrode is inoperable under these conditions

TaKidM thus, the proposed chalcogenide glass electrodes, compared with the prototype, have a 100–1000 times lower specific resistance, are 5–10 times more selective in the presence of hydrogen ions, and are operable in fluoride media.

Claims (1)

Invention Formula The composition of the chalcogenide glass electrode membrane for the determination of sodium ions, characterized in that 5 in order to increase the selectivity in the presence of hydrogen ions and work efficiency in fluoride media, the membrane contains sodium ord sulfide Gssh and the sulfide and disulfide 1 Germanic in the next lich e s. TV ak j m ol% i Sodium chloride 5--30 C ul galli feed 5 3 5 Germanium disulfite 20-85 Germanium sulfide Else Table 1 The membrane compositions of sodium selective chalcogenide glass electrodes and the weight of components required for the synthesis of 5 g of glass h;