JP3033494B2 - Fluoride ion analysis method and analysis reagent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for analyzing trace amounts of fluoride ions and an analytical reagent used for the method.

[0002]

2. Description of the Related Art Many methods for quantitative analysis of fluoride ions have been developed. However, most of them are insufficient in any of sensitivity, accuracy, and simplicity, and cannot always be said to be satisfactory methods.

In recent years, a spectrophotometric method using alizarin complexone as a color former has been developed (R. Belch).
er et. al. , J. et al. Chem. Soc. , 19
59, 3577. ). This method has become widely used because it is superior in many respects to previous methods.

[0004] For example, an analytical method using a complex of lanthanum and alizarin complexone is described in the Industrial Water Test Method (JIS).
-K0101), Factory drainage test method (JIS-K010)
2) and method for analyzing fluorine compounds in exhaust gas (JIS-K0
105).

[0005] Further, a flow injection analysis method for fluorine ions, which has obtained the effects of shortening the analysis time, improving the lower limit of analysis, and improving the analysis accuracy by performing the reaction between lanthanum and alizarin complexone at a high temperature, has been disclosed in Japanese Patent Application Laid-Open Publication No. HEI 7-163,197. 6
It is disclosed in Japanese Patent Application Laid-Open No. 1-100641.

[0006]

The method of using a complex of lanthanum and alizarin complexone as an analytical reagent, which is a method for quantitative analysis of fluoride ions, is currently widely used, and many improved methods are available. Is being developed.

However, the analytical lower limit of these methods is at most about several tens of nanograms, and it takes about 20 to 60 minutes from the addition of the analytical reagent to the completion of the color reaction. A disadvantage is that the error is as low as ± 5 to 20%.

[0008] An object of the present invention is to provide a method and an analytical reagent for fluoride ion analysis which have solved the conventional problems.

[0009]

In order to achieve the above object, a method for analyzing fluoride ions according to the present invention comprises measuring the fluorescence intensity of a fluorescent substance released from an analysis reagent by a substitution reaction with fluoride ions. Is used to determine the fluoride ion concentration.

The analysis reagent according to the present invention is a fluoride ion analysis reagent represented by the following general formula [1].

(Equation 2) [In the general formula [1], M represents any one of a cerium trivalent cation, a lanthanum trivalent cation, and an aluminum trivalent cation. In the general formula [1], A1, A2, A3 and A4 are
Each represents a substituent which may be the same or different. Examples of the substituent include a hydrogen atom, a halogen group, a hydroxyl group, an ether group, an alkoxy group, a carbonyl group, a carboxyl group or a metal complex compound thereof, a carboxylate ester, a thiol group, a sulfide group, a sulfonic acid group or a metal complex compound thereof, Represents an alkyl group or an aryl group which may have a group or a metal complex compound thereof, a heterocyclic group, or a substituent thereof. A1 and A2
May form one cyclohexane ring, and similarly, A3 and A4 may form one cyclohexane ring. In the general formula [1], B1, B2 and B3 represent a phenyl group or a derivative thereof. The substituents forming the phenyl group derivative may be the same or different from each other, and may be at any position of the phenyl group,
One or more phenyl groups may be used. Examples of the type of the substituent include a halogen group, a hydroxyl group, an ether group, an alkoxy group, a carbonyl group, a carboxyl group or a metal complex compound thereof, a carboxylate ester, a thiol group, a sulfide group, a sulfonic acid group or a metal complex compound thereof, An amino group, a metal complex compound thereof, a heterocyclic group, or an alkyl group or an aryl group which may have a substituent thereof. ]

The pH of the aqueous solution containing fluoride ions is adjusted from 7.0 to 1 with an acid or an alkali.
0.5, adjusting the heating temperature of the solution to a range of 20 to 100 ° C. by adding the analysis reagent according to claim 2 in an amount equivalent to or more than the estimated fluoride ion, The adjustment is made in the range of 1 to 60 minutes.

[0012]

The cerium trivalent cation, lanthanum trivalent cation, and aluminum trivalent cation form stable coordination bonds with fluoride ions. Therefore, these metal ions are given a more unstable ligand, 2-methylamino-4,
When 5-diphenylimidazole is bound,
A so-called substitution reaction occurs in which fluoride ions displace this ligand.

2 which has been desorbed from the metal ion by a substitution reaction
-Methylamino-4,5 diphenylimidazole changes its electronic state, so that the wavelength region and intensity of the fluorescence spectrum change. The fluorescence intensity is zero when bound to the metal, and by measuring the fluorescence intensity in a wavelength region (for example, 424 nm) where fluorescence is observed after release from the metal, the fluoride ion that has undergone the substitution reaction, The concentration of fluoride ions present in the test solution can be calculated.

[0014] Generally, fluorescence analysis can be performed with higher sensitivity than absorption spectroscopy. However, in the present invention, the lower limit of quantification is as low as about 100 times, that is, higher than that of the alizarin complexone method, which is an absorption analysis method. Sensitivity analysis is possible.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

The principle of the method for analyzing a fluoride ion according to the present invention is that a metal complex having a substance which emits fluorescence when desorbed from a metal ion as a ligand is used as an analysis reagent, and a metal complex with a fluoride ion to be analyzed is used. The fluoride ion concentration is calculated from the fluorescence intensity of the fluorescent substance desorbed by the substitution reaction.

As described above, in the method for analyzing fluoride ions according to the present invention, the pH adjustment, the heating temperature, and the heating time are determined by using a fluorometric method for the measurement of fluoride ions, using a novel analytical reagent. By using the operation method,
It performs highly sensitive measurements, and its analytical reagents are aluminum, cerium, and lanthanum as metal ions.
It is any of the cations, and has 2-methylamino-4,5-diphenylimidazole as a ligand.
Since this ligand is displaced and released in the test solution by a fluoride ion to be analyzed, the concentration of the fluoride ion is calculated by measuring the fluorescence intensity.

Further, in the present invention, as a novel analytical reagent,
A fluoride ion analysis reagent represented by the following general formula [1] is used.

(Equation 3) [In the general formula [1], M represents any one of a cerium trivalent cation, a lanthanum trivalent cation, and an aluminum trivalent cation. In the general formula [1], A1, A2, A3 and A4 are
Each represents a substituent which may be the same or different. Examples of the substituent include a hydrogen atom, a halogen group, a hydroxyl group, an ether group, an alkoxy group, a carbonyl group, a carboxyl group or a metal complex compound thereof, a carboxylate ester, a thiol group, a sulfide group, a sulfonic acid group or a metal complex compound thereof, Represents an alkyl group or an aryl group which may have a group or a metal complex compound thereof, a heterocyclic group, or a substituent thereof. A1 and A2
May form one cyclohexane ring, and similarly, A3 and A4 may form one cyclohexane ring. In the general formula [1], B1, B2 and B3 represent a phenyl group or a derivative thereof. The substituents forming the phenyl group derivative may be the same or different from each other, and may be at any position of the phenyl group,
One or more phenyl groups may be used. Examples of the type of the substituent include a halogen group, a hydroxyl group, an ether group, an alkoxy group, a carbonyl group, a carboxyl group or a metal complex compound thereof, a carboxylate ester, a thiol group, a sulfide group, a sulfonic acid group or a metal complex compound thereof, An amino group, a metal complex compound thereof, a heterocyclic group, or an alkyl group or an aryl group which may have a substituent thereof. ]

In the method for analyzing fluoride ions according to the present invention, the pH of the aqueous solution containing fluoride ions is adjusted to 7.0 to 10.5 with an acid or an alkali, and the above-described analysis is performed. The reagent is added in an amount equal to or more than the equivalent mole with respect to the estimated fluoride ion, the heating temperature of the solution is adjusted to 20 to 100 ° C., and the heating time is 1 to 6
It is adjusted to a range of 0 minutes.

Next, an embodiment of the present invention will be described. (Example 1) Determination of fluoride ions in a lubricating film of a hard disk medium.

Among the analytical reagents described in the embodiment, [bis (2,3-) is a compound in which M is a cerium trivalent cation, A1, A2, A3 and A4 are methyl groups, and B1, B2 and B3 are phenyl groups. Butanedione dioximato) (2-methylamino-4,5-diphenylimidazole) triphenylphosphine cerium (III)].

(1) Preparation of calibration curve Standard solution of sodium fluoride (10 pg / ml as F ⁻ )
) Was adjusted stepwise to pH = 8.5 with 0.1M aqueous sodium hydroxide solution. To each of the solutions, 1 ml of an aqueous solution of an analytical reagent having a concentration of 100 pg / ml was added, and the mixture was kept at 60 ° C. for 10 minutes. After cooling to room temperature, the volume was adjusted to 10 ml with pure water, and the fluorescence intensity was measured. The measurement conditions of the fluorescence intensity are excitation light wavelength 330 nm,
The measurement wavelength was 424 nm. FIG. 1 shows the relationship between the emission intensity and the fluoride ion concentration (calibration curve).

(2) Measurement of Test Liquid The lubricating film on the hard disk medium was dissolved in 50 ml of tetrafluoroisopropyl alcohol, and the fluoride ions in this solution were extracted with 5 ml of pure water. The aqueous phase was separated and collected, and the same operation as the operation after the pH adjustment in preparing the calibration curve was performed, and the fluorescence intensity of the test solution was measured in 10 ml of pure water. The analysis values were as shown in the following table.

[Table 1] The lower limit of quantification of fluoride ions in this analysis method was 10 picograms.

(Example 2) Determination of fluoride ion in river water. In the analysis reagents described in the embodiment, M is a trivalent aluminum cation, A1, A2, A3, and A4 are phenyl groups, and B1, B2, and B3 are 3-methoxyphenyl groups. [Bis (1,2-diphenylethanedione dioximato) (2-methylamino-4,5-diphenylimidazole) tri (3-methoxyphenyl) phosphin aluminum (III)] was used.

(1) Preparation of Calibration Curve The same operation as in the preparation of the calibration curve in Example 1 was performed.
However, the analysis reagent described in Example 2 was used as the analysis reagent. The calibration curve is shown in FIG.

(2) Measurement of Test Liquid Using river water as a test liquid, the same operation as the operation after pH adjustment in Example 1 was performed. The analysis values were as shown in the following table.

[Table 2] The lower limit of quantification of fluoride ion in this analysis method is as follows.
1.2 picograms.

(Example 3) Determination of fluoride ion in industrial water. In the analytical reagents described in the embodiment, M is a lanthanum trivalent cation, A1, A2 and A3, A4 are each a cyclohexane group, and B1, B2, and B3 are a 3-phenol group, [bis (1,2- Cyclohexanedione dioximato) (2-methylamino-4,5-diphenylimidazole) tri (3-phenol) phosphinlanthanum (III)] was used.

(1) Preparation of calibration curve The same operation as in the preparation of the calibration curve in Example 1 was performed. However, the analysis reagent of Example 3 was used as the analysis reagent. The calibration curve is shown in FIG.

(2) Measurement of Test Liquid The same operation as the operation after pH adjustment in Example 1 was performed using industrial water as a test liquid. The analysis values were as shown in the table below.

[Table 3] The lower limit of quantification of fluoride ions in this analysis method is as follows:
It was 15 picograms.

[0030]

As described above, according to the present invention, a fluorometric method using a metal complex as an analytical reagent is used. In this fluorometric method, there is used a spectrophotometric method using a conventional alizarin complexane analytical reagent. In comparison, the analysis lower limit can be improved by 50 to 100 times, the analysis accuracy can be improved by 10 times, and the analysis time can be shortened, and the analysis performance can be greatly improved. effective.

[Brief description of the drawings]

FIG. 1 is a calibration curve showing the relationship between the amount of fluoride ions and the emission intensity.

FIG. 2 is a calibration curve showing the relationship between the amount of fluoride ions and the emission intensity.

FIG. 3 is a calibration curve showing the relationship between the amount of fluoride ions and the emission intensity.

Claims (3)

(57) [Claims] 1. A fluoride ion analysis reagent represented by the following general formula [1]. (Equation 1) [In the general formula [1], M represents any one of a cerium trivalent cation, a lanthanum trivalent cation, and an aluminum trivalent cation. In the general formula [1], A1, A2, A3 and A4 are
Each represents a substituent which may be the same or different. Examples of the substituent include a hydrogen atom, a halogen group, a hydroxyl group, an ether group, an alkoxy group, a carbonyl group, a carboxyl group or a metal complex compound thereof, a carboxylate ester, a thiol group, a sulfide group, a sulfonic acid group or a metal complex compound thereof, A group or a metal complex compound thereof, a heterocyclic group, or a substituent thereof.
Represents an alkyl group or an aryl group. Also, A1 and A
2 may form one cyclohexane ring, and similarly, A3 and A4 may form one cyclohexane ring. In the general formula [1], B1, B2 and B3 represent a phenyl group or a derivative thereof. The substituents forming the phenyl group derivative may be the same or different from each other, may be at any position of the phenyl group, and may be singular or plural per phenyl group. Examples of the type of the substituent include a halogen group, a hydroxyl group, an ether group,
An alkoxy group, a carbonyl group, a carboxyl group or a metal complex compound thereof, a carboxylic acid ester, a thiol group, a sulfide group, a sulfonic acid group or a metal complex compound thereof, an amino group or a metal complex compound thereof, a heterocyclic group, or
An alkyl group or an aryl group which may have these substituents. ] 2. A method according to claim 1 Symbol in substitution reaction with fluoride ion
A method for analyzing a fluoride ion, comprising determining a fluoride ion concentration by measuring a fluorescence intensity of a fluorescent substance released from an analytical reagent described above. 3. The pH of an aqueous solution containing fluoride ions is adjusted to 7.0 to 10.5 with an acid or an alkali.
The analysis reagent according to claim 1 is added in an amount equivalent to or more than the estimated amount of fluoride ion, the heating temperature of the solution is adjusted to 20 to 100 ° C., and the heating time is adjusted to 1 to 60. A method for analyzing fluoride ions, wherein the method is adjusted to a range of minutes.