JPS6360860B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for rapidly quantifying chloride ions contained in various aqueous solutions and an inexpensive and simple measuring device for the same.

In recent years, there has been an increasing demand for a rapid method for quantifying chlorine ions contained in water, desalinated water, aqueous solutions of chemical products (e.g., drugs, etc.), aqueous solutions of concrete mixes, etc., and aqueous solutions of extracted solids such as sand. are doing. For example, concrete has traditionally been used as a structural material for civil engineering and construction, but since it is used for large buildings and structures such as roads, bridges, and dams,
Quality control for its strength and durability is important. In particular, care must be taken to ensure that the content of organic matter, acids, salts, etc. in the water and sand mixed into cement does not exceed the limits. For example, chlorine ion components do not pose much of a problem in unreinforced concrete, but in reinforced concrete, they are a major factor that promotes rusting of the reinforcing bars, so sufficient consideration is required.

However, there are conventional methods for measuring (testing) the content of chlorine ion components, such as the Japan Society of Civil Engineers standard for testing the salt content in sea sand, ``Method for testing salt content in sea sand'', ion electrode method, electrical Conduction method etc.
This method is extremely inconvenient as a means for measuring on-site because it takes a long time to perform the measurement and requires complicated operations or complicated equipment.

The present invention aims to provide a method and a measuring tool that can easily and accurately measure chlorine ions contained in various materials such as concrete mixes or sand without requiring complicated equipment or advanced technology. This is the purpose.

That is, in the present invention, one end of a capillary member impregnated with silver dichromate, which is sandwiched between plastic layers, is immersed in a test liquid while preventing the other end of the member from coming into contact with the test liquid. is caused to rise within the member, causing a color change to white due to the reaction between silver dichromate and chloride ions within the member, and a moisture-sensitive indicator provided in contact with the other end of the capillary member. When it is detected that the member is completely saturated with water, the length of the white change portion is read by a scale arranged along the length of the capillary member. A method for quantifying chloride ions contained in an aqueous solution is provided.

Furthermore, the present invention provides a support 5 made of a chemically inert material, a capillary member 2 impregnated with silver dichromate provided on the support 5, and a capillary member 2 on the support 5. 2, a transparent cover film 4 provided on the capillary member 2 and the moisture-sensitive indicator 3, and the support 5 or the transparent cover film 4. It consists of a reading scale 6 provided on the top,
To provide a chloride ion quantitative measuring instrument characterized in that the other end of the capillary member 2 is exposed so as to be able to come into contact with a test liquid.

The measuring device of the present invention acts on chlorine ions contained in the test liquid with a very clear color change, and can accurately measure the chlorine ions without misreading.

That is, when water containing chloride ions (Cl ^- ) in a liquid such as an aqueous solution of concrete mixes or sand is absorbed into a capillary material impregnated with silver dichromate, the chloride ions and dichromate The following chemical reaction occurs with silver, and the capillary material changes from brown to white up to a height corresponding to the concentration of chloride ions, so if the capillary material is calibrated appropriately using any method in the usual measurement system, Chlorine ions in the test solution can be measured extremely easily and quickly.

Ag ₂ Cr ₂ O ₇ +2NaCl→Na ₂ Cr ₂ O ₇ +2AgCl (brown) (white) Further, the upper end of the capillary material impregnated with silver dichromate, for example, perpendicularly in its longitudinal direction, is By placing capillary material impregnated with a moisture-sensitive indicator in contact with each other, water containing chloride ions absorbed by the capillary material impregnated with silver dichromate rises a certain distance and reacts with the moisture-sensitive indicator. This causes a color change. Therefore, the time for which the lower end of the capillary material impregnated with silver dichromate is immersed in the test liquid can be matched to an appropriate pre-adjusted time, making accurate measurements possible at all times.

Yet another feature of the present invention is that by providing a scale of correlated data along the length of the capillary member, data corresponding to a change in white color is immediately readable. Such scales differ depending on the type of test liquid and the purpose of measurement. For example, if precise measurements are required, a considerable number of scales are arranged at equal intervals in correspondence with correlation data.
On the other hand, if it is desired to check one or several important concentrations of chloride ions, a scale corresponding to such concentrations is sufficient. In this way, an appropriate scale can be selected in advance according to the purpose based on preliminary experiments so that the desired data value or the value that will be immediately converted to the required data value from the conversion table can be determined from the reading from the scale. I can do it.

The capillary material impregnated with the silver dichromate and moisture-sensitive indicators constituting the invention may be any material through which a fluid or solid can be adsorbed, absorbed, digested, or passed by dissolution, diffusion, sublimation, or capillary action. by means of capillary bodies, porous bodies or open-cell bodies in the form of fibers having continuous cavities of sufficiently small dimensions to be capable of wicking fluids primarily by adsorption. It has capillary properties. Preferably finely divided particulate materials, sponges or porous materials and fibrous materials, such as cellulose fibers or synthetic fiber networks having a large continuous internal surface area relative to their volume, such as textiles or papers, and more Preferably, it is paper using cellulose, synthetic, or glass fibers.

The capillary material impregnated with a moisture-sensitive indicator, ie, a moisture-sensitive indicator, may be a suitable capillary material, such as paper, containing a moisture-sensitive indicator such as Karl Fischer's reagent, such as lithium chloride or calcium chloride. Examples include those impregnated with hygroscopic substances.

As the plastic layer, various plastic films such as synthetic resin films such as polyethylene, polypropylene; polyvinyl polymers or copolymers such as polyvinyl chloride, polyvinyl acetate, polyvinylidene chloride and polyethylene; Any of the composite sheets can be conveniently used, such as in combination with polyethylene.

Note that at least one of the two plastic layers has sufficient transparency and is impregnated with silver dichromate so that the color reaction of silver dichromate and the moisture-sensitive indicator can be visually inspected. a scale extending along the length of the capillary material, water permeates along the capillary material into the appropriate measurement unit, and the chloride ions and silver dichromate react to change the color from brown to white. The length can be read by looking at it.

Embodiments of the present invention will be described below with reference to the drawings.

In Figures 1 _{to 5} , 2 is a capillary paper (6 _cm x 0.3 cm;SB-2;Reeve・
(manufactured by Angel Paper Co.), and the upper end of the capillary paper 2 is a moisture-sensitive indicator made by impregnating similar paper with a 1NHCl-bromophenol blue mixture (alcohol solvent) that changes color to dark blue when it comes into contact with moisture. The bodies 3 are arranged in contact with each other so as to be perpendicular to each other in the longitudinal direction, and a transparent synthetic resin film 4 for the cover is formed.
and white synthetic resin film 5 (support: 7.5 cm x
A measuring tool 1 is constructed by enclosing a capillary paper 2 with its lower end exposed between the two ends (1.3 cm).

The scale 6 is provided on the inner surface of the film 5 (the surface in contact with the film 4) at intervals of 1.2 mm over the entire length, and can be read through the film 4.
Such scales can also be provided on the inner or outer surface of the film 5. Note that 7 is a grip portion.

For measurement, if the object to be tested is, for example, concrete mix, it is sufficient to hold the grip part 7 and push the lower end of the measuring tool 1 into the concrete mix as shown in FIG. In addition, when testing dry sand used as aggregate, add 20% water by weight to the sand, and add one measuring tool to the extracted aqueous solution.
Immerse the bottom end of the In either case, when the moisture-sensitive indicator 3 changes color, it is immediately removed from the specimen and the scale 6 is read at the point where the capillary paper 2 changes color from brown to white. The concentration of chloride is measured. Since the lower end of the capillary paper 2 is always exposed, there is a risk that silver dichromate may undergo a chemical reaction before measurement due to various factors. It is preferable to store the measuring tool 1 sealed in a synthetic resin container 8 that can be easily opened.

Unlike conventional measuring devices, the measuring tool of the present invention is compact for easy portability, is not fragile like glass, is convenient to carry and handle, and is difficult to obtain accurately. provides an accurate and inexpensive means of measuring chloride concentrations in concrete mixes or sand that have not been previously available or that could only be obtained by relatively laborious, time-consuming and expensive measurement techniques. .

[Brief explanation of drawings]

The drawings show an embodiment of the measuring tool according to the present invention,
1 is a front view, FIG. 2 is an enlarged sectional view taken along the - line in FIG. 1, FIG. 3 is an enlarged sectional view taken also along the - line, FIG. The figure is a front view showing the state in which it is sealed in a storage container. 1... Measuring tool, 2... Capillary paper impregnated with silver dichromate, 3... Moisture-sensitive indicator, 4... Transparent synthetic resin film, 5... White synthetic resin film (support), 6... Graduation, 7 ...Gripper, 8...Synthetic resin container.

Claims (1)

[Claims] 1. One end of a capillary member impregnated with silver dichromate, which is sandwiched between plastic layers, is immersed in a test liquid without the other end of the member coming into contact with the test liquid. As moisture rises within the member, a reaction between silver dichromate and chloride ions causes a color change to white, and the water-sensitive indicator provided in contact with the other end of the capillary member Therefore, when it is detected that the member is completely saturated with water, the length of the white change portion is read by a scale arranged along the length of the capillary member. A method for quantifying chlorine ions contained in an aqueous solution. 2 a support 5 made of a chemically inert material, a capillary member 2 impregnated with silver dichromate provided on the support 5, and a capillary member 2 provided on the support 5;
a moisture-sensitive indicator 3 disposed in contact with one end, a transparent cover film 4 provided on the capillary member 2 and the moisture-sensitive indicator 3, and on the support 5 or the transparent cover film 4; A chloride ion quantitative measuring instrument comprising a reading scale 6 provided at the capillary member 2, the other end of the capillary member 2 being exposed so as to be able to come into contact with a test liquid.