JP2010223782A - Method for stabilizing fluorescence intensity of rhodamine-based fluorescent material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for stabilizing the fluorescence intensity of a rhodamine-based fluorescent material and capable of lessening reductions in fluorescence intensity with the passage of time when using a rhodamine-based fluorescent material as a tracer of additives and accurately measuring the concentration of additives, for example, a water treatment chemical over a long period and to provide a water treatment chemical containing a fluorescent tracer. <P>SOLUTION: The method for stabilizing the fluorescence intensity of a rhodamine-based fluorescent material is constituted by making a rhodamine-based fluorescent material and a pigment having absorption maximum in a wavelength range of ≥610 nm and ≤640 nm coexist in order to solve the problem. The water treatment chemical containing a fluorescent tracer is achieved by mixing one type or more of water treatment chemical selected from a corrosion inhibitor, a scale inhibitor, and a slime control agent; a rhodamine-based fluorescent material; and a pigment having absorption maximum within the wavelength range of ≥610 nm and ≤640 nm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for stabilizing the fluorescence intensity of a fluorescent substance added to an aqueous system. Specifically, the present invention relates to a method for stabilizing the fluorescence intensity of a rhodamine-based fluorescent material used as a tracer for detecting and quantifying the concentration of a water treatment chemical.

  In water systems such as open circulation cooling water systems, various water treatment chemicals are used to prevent damage caused by water such as corrosion, scale, slime and the like. In general, water treatment chemicals used in water systems include corrosion inhibitors, scale inhibitors, slime control agents (biofouling inhibitors), and the like.

  In order to fully demonstrate the effects of the addition of these water treatment chemicals in an aqueous system, the concentration of the water treatment chemical added in the aqueous system is accurately grasped at an arbitrary position, time, etc. It is important to manage the concentration so that it is appropriate.

  However, depending on the type of water treatment chemical, there are some cases where it is impossible or difficult to measure the concentration in water. Therefore, in water systems, a substance that can be easily measured is used as a tracer as a method for managing the concentration of a water treatment agent when it is impossible or difficult to measure its own concentration as a water treatment agent. Things have been done.

  According to the method using this tracer, even if it is impossible or difficult to measure its own concentration, it is possible to quickly estimate the concentration of the water treatment agent in the water.

  As a method using this tracer, there is a fluorescent tracer method in which the concentration of the water treatment chemical is estimated by adding a fluorescent substance as a tracer substance to the water system together with the water treatment chemical disclosed in Patent Documents 1 and 2.

  In general, a substance used as a fluorescent tracer in the fluorescent tracer method is desired to satisfy the following conditions. (1) It does not exist in industrial water or the like, or it is negligible even if it exists. (2) Emits strong fluorescence. (3) Do not decompose easily due to the action of microorganisms. (4) It is substantially harmless from the viewpoint of pollution prevention. (5) No corrosiveness to metal materials such as water-based piping materials.

  Rhodamine fluorescent substances are known as excellent fluorescent substances that satisfy the conditions (1) to (5) above. The rhodamine fluorescent substance is a red dye, and is usually a pigment that emits orange (580 nm) fluorescence when receiving green (520 nm) light.

  By using a fluorescent tracer method using a rhodamine-based fluorescent substance as a tracer, it is possible to accurately grasp the concentration of the water treatment chemical at a measurement site in a short time with a simple measurement operation, if necessary.

Japanese Patent Laid-Open No. 07-128324 Japanese Patent Application Laid-Open No. 09-177862

  However, when a rhodamine fluorescent substance is added to a water system as a tracer substance (fluorescent substance) together with a water treatment chemical or mixed into a water treatment chemical to form a one-part preparation, the fluorescence intensity increases over time. There was a problem that the concentration of water treatment chemicals could not be accurately grasped.

  Therefore, the present invention suppresses the decrease in fluorescence intensity over time when a rhodamine-based fluorescent substance is used as an additive tracer, and the concentration of an additive, for example, a water treatment chemical, can be more accurately determined over a long period of time. It is an object of the present invention to provide a method for stabilizing the fluorescence intensity of a rhodamine-based fluorescent substance and a water treatment chemical containing a fluorescent tracer that can be measured in a simple manner.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have made a rhodamine-based fluorescent substance coexisting with a rhodamine-based fluorescent substance and a dye having an absorption maximum in a specific wavelength range, even if time passes. The present inventors have found that the fluorescent substance can be stabilized by suppressing a decrease in the fluorescence intensity, and have completed the present invention based on this finding.

  That is, in order to solve the above-mentioned problems, the present invention provides a method for stabilizing the fluorescence intensity of a rhodamine-based fluorescent material, characterized by coexisting a rhodamine-based fluorescent material and a dye having an absorption maximum in a wavelength range of 610 nm to 640 nm. The configuration was as follows. In addition, when a rhodamine fluorescent substance is added to an aqueous system as a tracer for a water treatment agent, a dye having an absorption maximum in the range of wavelengths from 610 nm to 640 nm coexists in the aqueous system. It was set as the structure of the stabilization method. When a rhodamine-based fluorescent substance used as a tracer for water treatment chemicals is mixed with at least one of a corrosion inhibitor, a scale inhibitor and a slime control agent to prepare a formulation, the wavelength in the formulation is 610 nm or more and 640 nm or less. A method for stabilizing the fluorescence intensity of a rhodamine-based fluorescent material characterized in that a dye having an absorption maximum coexists.

  Furthermore, the rhodamine fluorescent substance is rhodamine WT, the constitution of the method for stabilizing fluorescence intensity of rhodamine fluorescent substance according to any one of the above, and a dye having an absorption maximum in the wavelength range of 610 nm to 640 nm Is a dye preparation containing at least one selected from Blue No. 1, Blue No. 2, Green No. 3, Black No. 401, or at least one of these dyes. The configuration of the method for stabilizing the fluorescence intensity of a fluorescent substance was used.

  In addition, one or more water treatment agents selected from a corrosion inhibitor, a scale inhibitor, and a slime control agent, a rhodamine fluorescent substance, and a dye having an absorption maximum in a wavelength range of 610 nm to 640 nm, It was set as the structure of the water treatment chemical | medical agent containing a fluorescent tracer characterized by mixing.

  As the rhodamine fluorescent substance, rhodamine WT, rhodamine B, rhodamine 6G and derivatives thereof, rhodamine 123, rhodamine 101 and the like are generally well known, and they can be employed in the present invention. Rhodamine WT and rhodamine B are similar compounds, and both have been used as tracers since the 1960s in nature and industrial water systems.

  Rhodamine WT (CAS registration number: 37299-86-8) was developed to compensate for the shortcomings of rhodamine B absorbed by suspended sediment, and has reduced toxicity. It is also approved for use as a tracer and is optimal in the present invention.

  In the present invention, the dye coexisting with the rhodamine-based fluorescent substance is not particularly limited as long as it has a maximum absorption in the wavelength range of 610 nm to 640 nm, but it is a legal dye (tar dye) because it is highly stable and difficult to fade. ), Particularly those approved as food additives.

  Preferred legal dyes having an absorption maximum in the wavelength range from 610 nm to 640 nm include Blue No. 1, Blue No. 2, Green No. 3, Black No. 401, etc., and are designated as food additives from the viewpoint of safety. Blue No. 1, Blue No. 2, and Green No. 3 are particularly preferable.

  Moreover, as a preferable pigment preparation having an absorption maximum in a wavelength range of 610 nm to 640 nm, melon color and chocolate color B manufactured by Shinko Co., Ltd. can be exemplified. Moreover, the mixture of the said melon color and chocolate color B shows a synergistic effect, and is especially preferable. The melon color is a mixed dye of yellow No. 4 and blue No. 1 and the chocolate color is a mixed dye of red No. 2, red No. 102, yellow No. 4 and blue No. 2.

  Since this invention is the said structure, it can grasp | ascertain correctly the density | concentration of the additive added especially to a water system over a long period of time, especially a water treatment chemical | medical agent.

It is the result of Example 1 which investigated the time-dependent change in the fluorescence intensity of the mixture with a rhodamine type fluorescent substance (rhodamine WT) and various pigments at normal temperature (room temperature). It is the result of Example 2 which investigated the influence of the heat | fever with respect to the fluorescence intensity of the mixture with a rhodamine type fluorescent substance (rhodamine WT) and various pigment | dyes. It is the result of Example 3 which investigated the influence of the direct sunlight with respect to the fluorescence intensity of the mixture with a rhodamine type | system | group color firefly substance (rhodamine WT) and various pigment | dyes. It is the result of Example 4 which investigated the temporal change in the fluorescence intensity of the water treatment chemical | medical agent which mixed the rhodamine type fluorescent substance (rhodamine WT) and various pigment | dyes with the water treatment chemical | medical agent at the normal temperature.

  Below, based on an accompanying drawing, the fluorescence intensity stabilization method of the rhodamine type fluorescent substance which is this invention is demonstrated in detail.

  FIG. 1 shows the results of Example 1 in which the change over time in the fluorescence intensity of a mixture of a rhodamine-based fluorescent substance (rhodamine WT) and various dyes at room temperature (room temperature) was examined.

[experimental method]
Add rhodamine WT, which is a fluorescent substance for tracer, and various dyes (legal dye = 9 kinds, dye preparation = 3 kinds) to pH buffer solution adjusted to pH = 8.0 by adding phosphate buffer to pure water , Mixed and left at room temperature for 40 days. Thereafter, the concentration (mg / L) of rhodamine WT was measured.

  The concentration (mg / L) of rhodamine WT in the pH buffer solution was determined according to Experiment No. In Nos. 1 to 13, the rhodamine WT concentration was 60 mg / L (high concentration test group). In 14-25, the rhodamine WT concentration was 10 mg / L (low concentration test group).

  The tested pigments are as shown in FIG. 1, the chocolate color B and melon color are pigment preparations manufactured by Shinko Co., Ltd., and the others are legal pigments. In the rhodamine WT high-concentration test group, the amount of dye added was 1000 mg / L, and the test No. 1 was tested as a mixed dye. In No. 13, the total weight was 1000 mg / L at a 1: 1 weight ratio. In the rhodamine WT low-concentration test group, the amount of dye added was 1 mg / L, and the test No. 1 was tested as a mixed dye. In No. 25, the total weight was 1 mg / L at a 1: 1 weight ratio.

  The absorption maximum wavelength (nm) of each dye is also as shown in the table of FIG. In addition, when there are two or more absorption maximum wavelengths within the visible wavelength (about 400 to 800 nm), they are shown in the order of increasing absorption spectrum height in the table. The same applies to FIGS.

  The concentration of rhodamine WT is obtained in advance by measuring the fluorescence intensity of rhodamine WT using a fluorimeter (model: RF-1500) manufactured by Shimadzu Corporation, and measuring rhodamine WT having a known concentration from the measured fluorescence intensity. It was determined using a standard curve. Rhodamine WT has an excitation light wavelength of 558 nm and a fluorescence measurement wavelength of 575 nm. The same applies to Examples 2 to 4.

[result]
As a result of the experiment, the following became clear. In the rhodamine WT high-concentration test group, the concentration of rhodamine WT after standing for 40 days at room temperature when no dye was added (Experiment No. 1) was 18 mg / L, so the residual rate was 30%. The residual rate (%) was calculated by rhodamine WT (mg / L) at the time of measurement / rhodamine WT (mg / L) at the time of addition × 100, and the first decimal place was rounded off. same as below.

  On the other hand, when the dye was added, yellow No. 4, orange No. 201, brown No. 201, red No. 2, purple No. 401 (Experiment No. 2 to 6) had only a slight improvement in the residual rate. there were. The residual rate was in the range of about 33-50%. A dye having an absorption maximum at a longer wavelength position tended to have a higher residual ratio, that is, improved the temporal stability of rhodamine WT. Therefore, the residual rate of rhodamine WT was higher when the chocolate color B and the melon color 1 type were added (Experiment Nos. 11 and 12).

  When the chocolate color B and the melon color were mixed (Experiment No. 13), the residual rate (98%) was significantly improved (Experiment No. 13) as compared with the case where each was added alone (Experiment No. 11.12). This is considered to be due to the shift of the absorption wavelength region due to the interaction of both dyes and the increase in the amount of absorption at 630 nm. A mixed preparation of chocolate color B and melon color is also extremely effective in improving the stability of rhodamine WT.

  Furthermore, the addition of Green No. 3, Blue No. 1, Black No. 401 and No. Blue No. 2 (Experiment No. 7 to 10) showed an extremely high residual rate in the range of about 87 to 100%. With such a high residual rate, it is possible to accurately control the additive concentration over a long period of time as a tracer substance used to control the concentration of additives such as water-based water treatment chemicals, which is extremely beneficial. It is. In addition, the results in the low-concentration rhodamine WT test section showed the same tendency as the results in the high-concentration rhodamine WT test section.

  From the above, it has been clarified that a dye having an absorption maximum wavelength (nm) of about 610 to 640 nm can greatly improve the temporal stability of rhodamine WT in a room temperature environment.

  FIG. 2 shows the results of Example 2 in which the influence of heat on the fluorescence intensity of a mixture of a rhodamine fluorescent substance (rhodamine WT) and various dyes was examined.

[experimental method]
Add rhodamine WT, which is a fluorescent substance for tracer, and various dyes (legal dye = 9 kinds, dye preparation = 3 kinds) to pH buffer solution adjusted to pH = 8.0 by adding phosphate buffer to pure water , Mixed and warmed to 55 ° C. and held at 55 ° C. for 20 days. Thereafter, the concentration (mg / L) of rhodamine WT was measured from the fluorescence intensity in the same manner as in Example 1.

The concentration of rhodamine WT in the pH buffer solution was 60 mg / L, and the added dye was the same as Example 1 except that the concentration was 200 mg / L (experiment No. 13 was the total).
[result]
As a result of the experiment, the following became clear. Since the concentration of rhodamine WT after standing for 22 days at 55 ° C. when no dye was added (Experiment No. 1) was 3 mg / L, the residual rate was 5%.

  On the other hand, when the dye was added, yellow No. 4, orange No. 201, brown No. 201, red No. 2, purple No. 401 (Experiment No. 2 to 6) had only a slight improvement in the residual rate. is there. The residual rate was in the range of about 7-12%. Moreover, the residual rate of rhodamine WT was still higher in the case of adding one chocolate color B and one melon color (Experiment Nos. 11 and 12).

  Furthermore, the addition of Green No. 3, Blue No. 1, Black No. 401 and Blue No. 2 (Experiment Nos. 7 to 10) showed a very high residual rate in the range of about 83 to 98%, and it also showed rhodamine against heat. It has been shown to improve the stability of WT. This indicates that, as in Example 1, these dyes can be used to stabilize the fluorescence intensity of rhodamine WT. A mixed preparation of chocolate color B and melon color is also extremely effective for improving the stability of rhodamine WT.

  FIG. 3 shows the results of Example 3 in which the influence of direct sunlight on the fluorescence intensity of a mixture of a rhodamine-based color firefly substance (rhodamine WT) and various dyes was examined.

[experimental method]
Add rhodamine WT, which is a fluorescent substance for tracer, and various dyes (legal dye = 9 kinds, dye preparation = 3 kinds) to pH buffer solution adjusted to pH = 8.0 by adding phosphate buffer to pure water , Mixed, sealed the transparent glass container, and allowed to stand in a place exposed to direct sunlight for 10 days. Thereafter, the concentration (mg / L) of rhodamine WT was measured from the fluorescence intensity in the same manner as in Example 1.

  The concentration of rhodamine WT in the pH buffer solution was 10 mg / L, and the added dye was the same as Example 1 except that the concentration was 50 mg / L (experiment No. 13 was the total).

[result]
As a result of the experiment, the following became clear. The residual rate was 10% because the concentration of rhodamine WT after standing for 10 days at 55 ° C. and in direct sunlight was 1 mg / L when no dye was added (Experiment No. 1).

  In the case where a dye is added, yellow No. 4, orange 201, brown 201, red No. 2, purple No. 401 (experiment No. 2 to 6) is equivalent to the case where no dye is added (experiment No. 1). There was only a slight improvement in the residual rate. The residual rate was in the range of 10-20%. Moreover, the residual rate of rhodamine WT was still higher in the case of adding one chocolate color B and one melon color (Experiment Nos. 11 and 12).

  Furthermore, the addition of Green No. 3, Blue No. 1, Black No. 401 and No. Blue No. 2 (Experiment No. 7 to 10) showed a very high residual rate in the range of 70 to 90%, and rhodamine WT against sunlight. It became clear to improve the stability of. This indicates that, as in Example 1, these dyes can be used to stabilize the fluorescence intensity of rhodamine WT. A mixed preparation of chocolate color B and melon color is also extremely effective for improving the stability of rhodamine WT.

  FIG. 4 shows the results of Example 4 in which the change over time in the fluorescence intensity of a fluorescent tracer-containing water treatment agent obtained by mixing a water treatment agent with a rhodamine-based fluorescent substance (rhodamine WT) and various dyes was examined.

[experimental method]
1% by weight of 2-bromo-2-nitropropane-1,3-diol (mainly used as a slime control agent) as a water treatment agent, and 0.01% by weight (concentration) of rhodamine WT as a tracer. In a mixed solution containing 100 mg / L), 0.03 wt% (concentration: 300 mg / L) of various dyes (legal dyes = 4 kinds) was added and mixed, and allowed to stand at room temperature for 40 days. Thereafter, the concentration (mg / L) of rhodamine WT was measured from the fluorescence intensity in the same manner as in Example 1. Legal yellow No. 4, red No. 2, green No. 3, and blue No. 1 were used as dyes.

[result]
As a result of the experiment, the following became clear. When no dye was added (Experiment No. 1), the concentration of rhodamine WT after standing for 40 days was 2 mg / L, so the residual rate was about 2%.

  In Yellow No. 4 and Red No. 2 which are dyes having no absorption maximum in the wavelength range of 610 nm or more and 640 nm or less, the improvement in the stability of rhodamine WT is recognized as in the case where no dye is added (Experiment No. 1). Or only slightly improved. On the other hand, in Green No. 3 and Blue No. 1, which are dyes having absorption maximums in the wavelength range of 610 nm to 640 nm, the residual ratio of rhodamine WT is 70 to 85%, which is extremely high. From this, it was shown that it is effective for the fluorescence intensity stability of the fluorescent tracer substance even in the coexistence environment with the water treatment chemical.

  The method for stabilizing the fluorescence intensity of a rhodamine-based fluorescent material according to the present invention can accurately grasp the concentration of a water treatment agent over a long period of time in an aqueous system such as an open circulation cooling water system. Management becomes possible. In addition, it is possible to accurately protect water-based equipment.

Claims (6)

  A method for stabilizing the fluorescence intensity of a rhodamine fluorescent material, comprising coexisting a rhodamine fluorescent material and a dye having an absorption maximum in a wavelength range of 610 nm to 640 nm.   Stabilization of fluorescence intensity of rhodamine-based fluorescent material characterized by coexistence of a dye having an absorption maximum in the wavelength range of 610 nm to 640 nm in addition to rhodamine-based fluorescent material as a water treatment chemical tracer Method.   When a rhodamine-based fluorescent substance used as a tracer for water treatment chemicals is mixed with at least one of a corrosion inhibitor, a scale inhibitor and a slime control agent to prepare a formulation, the wavelength in the formulation is 610 nm or more and 640 nm or less. A method for stabilizing the fluorescence intensity of a rhodamine-based fluorescent material, characterized by coexisting a dye having an absorption maximum.   The method for stabilizing fluorescence intensity of a rhodamine-based fluorescent material according to any one of claims 1 to 3, wherein the rhodamine-based fluorescent material is rhodamine WT.   The dye preparation having at least one selected from Blue No. 1, Blue No. 2, Green No. 3, Black No. 401, or at least one of these dyes, as the dye having an absorption maximum in the wavelength range of 610 nm to 640 nm. The method for stabilizing fluorescence intensity of a rhodamine-based fluorescent material according to any one of claims 1 to 4, wherein:   One or two or more water treatment agents selected from a corrosion inhibitor, a scale inhibitor, and a slime control agent, a rhodamine fluorescent substance, and a pigment having an absorption maximum in the wavelength range of 610 nm to 640 nm are mixed. A water treatment chemical containing a fluorescent tracer,

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