JPS6210686Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electrolytic cell for coulometric titration.

Attempts have been made to apply the coulometric titration method to the Karl Fischer method, and FIG. 1 shows an electrolytic cell for coulometric titration used to carry out such an application.

In this electrolytic cell, an electrolyte b' containing iodine ions is placed in an anode chamber b equipped with an anode a, and an electrolyte b' is placed in a cathode chamber e, which is equipped with a cathode c and is separated from the anode chamber b by an electrolytic diaphragm d. A counter-electrode solution e' of the same type or a different type is placed in the anode chamber b, and a sample is added to the anode chamber b through the sample injection port f, and a current is passed through the anode chamber b.

Further, g and g' in the figure are drying tubes, and the anode chamber b and the cathode chamber e are in communication with the outside air through the drying tubes g and g', respectively. e
The pressure inside becomes almost equal to the outside pressure, preventing abnormal increases and decreases in pressure due to temperature changes, and moisture from the outside air is also absorbed by the drying tubes g and g', so that the inside of each chamber b and e is The structure is such that it also prevents moisture from entering.

Note that h is an end point indicating electrode for detecting a suitable end point, and i is a stirring bar for stirring the electrolytic solution b', which is rotated by a rotating magnetic field (not shown).

However, in such a conventional example, since the anode chamber b and the cathode chamber e are separated as described above, the drying tubes g and g' must be separately provided in each chamber b and e. Therefore, the configuration must become complicated.

In addition, if the sample to be quantitatively titrated contains a reducing agent or oxidizing agent that may undergo oxidation, it is necessary to maintain the anode chamber b in a reducing atmosphere. gas in the same room b
As a result, it has become a cumbersome and time-consuming operation.

The object of the present invention is to provide an electrolytic cell for coulometric titration which can eliminate the above-mentioned drawbacks.

The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 2 shows an electrolytic cell according to the present invention, in which an anode chamber 1 and a cathode chamber 2 are formed in communication via a communication port 3.

That is, a conduction port 3 is formed in the peripheral wall 2' of the cathode chamber 2, one end 3' of which opens to the outer peripheral surface of the cathode chamber 2, and the other end 3'' opens to the top surface. The one end 3' of the communication port 3 is located above the liquid level of the electrolytic solution 1' in the anode chamber 1.

The pore diameter and cross-sectional shape of the communication port 3 are not particularly limited as long as the gas generated from the counter electrode liquid 2' in the cathode chamber 2 can flow therethrough, but the pore diameter is preferably about several mm in practical terms. .

Further, the other end 3'' of the communication port 3 is opened at the top surface of the cathode chamber 2, but when the counter electrode solution 2' is injected from the upper end of the cathode chamber 2, the counter electrode solution 2' mixes into the electrolyte solution 1'. In order to avoid this, the counter electrode liquid 2' is
Care must be taken to prevent the flow from flowing into the other end 3'', but of course the opening may be made at a location other than the above.
It may be opened below one end 3'.

In addition, 4 is a lid that is fitted over the upper end opening of the cathode chamber 2, an electrolytic diaphragm 5 is provided on the bottom surface of the cathode chamber 2 as in the conventional example, 6 is a drying tube of the anode chamber 1, and 7 is a lid that is fitted to the upper end opening of the cathode chamber 2.
8 is the end point indicator electrode, 9 is the stirring bar,
10 is an anode, and 11 is a cathode.

Next, in order to use the electrolytic cell with the above configuration, the electrolytic solution 1' is injected from the sample injection port 7, and the counter electrode solution 2' is injected from the upper end port of the cathode chamber 2, and then the sample injection port 7 is injected. The cathode chamber 2 is sealed tightly and a lid 5 is placed on the upper end of the cathode chamber 2, and then electricity is applied between the electrodes 10 and 11. The gas generated from the counter electrode liquid 2' by energization rises and flows into the other end 3'' of the communication port 3, flows out from the one end 3' into the anode chamber 1, and then passes through the drying tube 6 to the outside air. At the same time, the gas generated from the electrolytic solution 1' is also discharged from the drying tube 6 to the outside air.

As described above, the present invention provides an electrolytic cell for coulometric titration that includes an anode chamber and a cathode chamber separated by an electrolytic diaphragm, and in which one chamber is provided inside the other chamber. The two chambers are in communication with each other through a conduction port formed above the electrolyte level in one of the chambers, and one chamber can be isolated from the atmosphere, and the other chamber is communicated with the outside air through a drying pipe. Therefore, the gas generated from the counter electrode liquid 2' rises in one chamber 2, flows into the communication port 3, reaches the other chamber 1, and from there flows out to the outside air through the drying tube 6. Therefore, one of the chambers 2 can be isolated from the outside air during electrolysis, and therefore there is no need to provide a drying pipe to prevent moisture from entering the outside air, and the configuration can be simplified. can.

Furthermore, since one chamber 2 and the outside air communicate with each other through the conduction port 3 and the other chamber 1, one chamber 2
This can prevent the occurrence of abnormal pressurization or depressurization inside the tank.

Moreover, according to the present invention, when the sample to be quantitatively titrated is a reducing agent that may undergo air oxidation, in conventional products, it is necessary to introduce an inert gas or the like to create a reducing atmosphere in the anode chamber. On the other hand, since the hydrogen gas generated from one chamber 2 flows into the other chamber 1 through the inlet 3, the inside of the chamber 1 is maintained in a reducing atmosphere, and there is no need to introduce inert gas etc. from the outside. .

In addition, if the sample to be quantitatively titrated is an oxidizing agent, if hydrazine salt is placed in one chamber 2 in advance, _N2 gas will be generated, and the other chamber 1 will become a reducing atmosphere in the same way as above. Therefore, there is no need to introduce an inert gas or the like from the outside in the same way as above.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a conventional electrolytic cell for coulometric titration, and FIG. 2 is a longitudinal sectional view showing an electrolytic cell for coulometric titration according to the present invention. 1...other chamber, 2...one chamber, 3...conducting port, 5...electrolytic diaphragm, 6...drying tube.

Claims (1)

[Claims for Utility Model Registration] (1) In an electrolytic cell for coulometric titration comprising an anode chamber and a cathode chamber separated by an electrolytic diaphragm, and one chamber is provided inside the other chamber, the anode chamber and the cathode chamber are communicated with each other by a communication port formed in one of the chambers and located above the electrolyte level, and one chamber can be isolated from the outside air, and the other chamber is connected to the cathode chamber through a drying pipe. Electrolytic cell for coulometric titration that communicates with the outside air. (2) One chamber is a cathode chamber, and the other chamber is an anode chamber, and a conduction port is formed in the peripheral wall of the cathode chamber, and one end of the conduction port is connected to the outer peripheral surface of the cathode chamber. The electrolytic cell for coulometric titration according to claim 1, wherein the other end is opened at the top surface and the electrolytic diaphragm is provided at the bottom surface of the cathode chamber.