JPH11326222A - Method for measuring dioxin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for indirectly determining dioxin by eliminating the need for the concentration operation of a sample and using a relatively inexpensive device. SOLUTION: In a measurement method, a sample for measuring the metal complex of 8-oxyquinoline and dioxin is mixed to an organic solvent containing halogen, and the fluorescence intensity is measured by applying excitation light to it, thus determining halophenol with concentration correlation with dioxin being contained in the sample and estimating the concentration of dioxin from the concentration of the halophenol. In this case, the metal complex of 8- oxyquinoline is tris (8-quinolinolate) aluminum (III), an organic agent containing halogen is chloroform, and halophenol is chlorophenol containing at least one nitrogen in a molecule. Also, an excitation light wavelength ranges from 300-45 nm and a fluorescence wavelength ranges from 450 to 600 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for indirectly quantifying dioxins by measuring halophenols contained in flue gas or the like generated during the incineration of general waste and industrial waste.

[0002]

2. Description of the Related Art According to a recent investigation, it has become clear that a high concentration of dioxins is generated when waste is incinerated, which has become a social problem. The concentration of dioxins contained in the exhaust gas at the time of incineration is 0.1 ng / Nm ^{3 in} terms of the total amount of dioxin and its homologues and isomers and polychlorinated dibenzofuran homologues and isomers because dioxin is very toxic. It has become mandatory to: However, because dioxin is so toxic, low concentrations that cannot be detected by ordinary analytical methods are problematic, and because it contains many dusts, mist, and a variety of other contaminants, dioxins are directly and accurately determined. A complicated pretreatment and a special analyzer are required for detecting and quantifying, and it is difficult to measure frequently. Moreover, it is practically impossible to monitor the combustion state that changes every moment.

[0003] As a representative method for quantifying and analyzing dioxins, there is a method described in Shimadzu Journal (Vol. 4, 1992). That is, using a Soxhlet extractor, a solvent such as toluene or ethylene glycol is used.
After solvent extraction for a time, after cleanup and concentration processing,
It is a method of analyzing by gas chromatography / mass spectrometer. In this method, since the steps required for the analysis such as the concentration treatment are complicated, it takes 2 to 3 weeks until the analysis result is obtained, and the analysis cost is high.

Accordingly, various methods for detecting dioxins have been considered. As a practical analysis method, instead of directly analyzing dioxins, measurement of alternative substances such as carbon monoxide and organic compounds that are said to be highly correlated with the concentration of dioxins in the sample is carried out, and dioxins are analyzed. An estimation method has been proposed. The method using carbon monoxide as an alternative substance allows continuous measurement without the need for pretreatment, but when the concentration of carbon monoxide is about 50 ppm or less, the correlation with dioxin is low and the practicality is poor. On the other hand, an organic compound is considered to be an effective index because a high correlation with dioxin is recognized even at 50 ppm or less.
As a typical organic compound, a method using chlorobenzene or chlorophenol as an index is disclosed.
JP-A-5-321796, JP-A-8-26686
In Japanese Patent Publication No. 3 and JP-A No. 9-15229, the organic compounds are quantified by gas chromatography. However, due to the problem of detection sensitivity, it is necessary to perform a concentration operation of a sample which is complicated and easily causes a measurement error. Also, Japanese Patent Application Laid-Open No. 9-2436
No. 01 discloses a method in which a laser ion mass spectrometer does not require concentration processing of a sample and can perform quantification in real time, but cannot be mounted on an old mass spectrometer, and the analyzer itself is very expensive. It is.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for indirectly quantifying dioxins using a relatively inexpensive apparatus which can eliminate the need for a sample concentration operation. Is to do.

[0006]

That is, the present invention provides a method for mixing a metal complex of 8-oxyquinoline and a sample to be measured for dioxins with an organic solvent containing halogen, and irradiating the mixture with excitation light. Dioxins contained in the sample by measuring the fluorescence intensity to determine the concentration of the dioxins, which has a concentration correlation with the dioxins, and estimating the concentration of the dioxins from the concentration of the halophenols. It is a measuring method.

The metal complex of 8-oxyquinoline is tris (8-quinolinolate) aluminum (III) (hereinafter abbreviated as AlQ3), the organic solvent containing halogen is chloroform, and the halophenol is one or more in the molecule. It is a chlorophenol containing chlorine and the excitation light wavelength is 3
It is advantageous that the fluorescence wavelength is from 00 to 450 nm and from 450 to 600 nm.

Hereinafter, the principle of the present invention will be described in detail.
The present invention relates in principle to Chemitsry letters, p1239-1242, 199
According to method 4. First, the object to be quantified is irradiated with light of a specific wavelength, the energy level is specifically raised, and the resulting fluorescence intensity from the object is measured, and the amount of the object is measured. By the fluorescence spectrum method. The measurement of the fluorescence spectrum can be performed by a known method. Generally, in a dilute solution, a cell containing a sample is irradiated with excitation light, and fluorescence is measured from a direction perpendicular to the excitation light. On the other hand, when the concentration of the solution is high, the fluorescence by the excitation light is absorbed by the solution (solute),
It can happen that the fluorescence intensity is measured small. In such a case, it is possible to cope with the problem by measuring the fluorescence from the vicinity of the surface irradiated with the excitation light. However, it is desirable to measure with a dilute solution in which such a phenomenon does not occur.

The excitation spectrum method measures the luminous intensity of a luminescent substance that emits fluorescence or phosphorescence at a specific measurement wavelength while changing the wavelength of the excitation light. This indicates energy dependence. This method is superior to the absorption spectrum method in that only species that emit light at a specific wavelength can be measured in a limited manner, and that the concentration and the transmission distance of sampling light are not limited.

The concentration of the halophenol is determined by obtaining the relationship between the concentration of the halophenol / fluorescence intensity in a solution containing a fluorescent substance (metal complex) as a fixed concentration of a fluorescent source, for example, by preparing a calibration curve in advance. By doing so, it becomes possible to easily measure. This is based on the phenomenon that the coexistence of a halophenol with a fluorescent substance increases the fluorescence intensity.

The 8-oxyquinoline used in the present invention may be any substance that exhibits fluorescence as a metal complex, and 8-oxyquinoline and 2-methylquinones, which exhibit a fluorescence intensity suitable for measurement, may be used. Examples thereof include -8-oxyquinoline and 4-methyl-8-oxyquinoline, among which 8-oxyquinoline is preferable.

The metal used in this metal complex may be any metal as long as it forms a complex with 8-oxyquinolines and exhibits fluorescence. As a coordinating metal exhibiting a fluorescence intensity suitable for measurement, boron is used. And a group 3 compound of an aluminum group and a rare earth group excluding the above. Among them, aluminum is preferable.

The halogen-containing organic solvent used in the present invention may be any solvent containing a halogen-containing organic substance that dissolves the 8-oxyquinoline metal complex.
Specific examples include chloromethane, dichloromethane, chloroform, carbon tetrachloride and the like, of which chloroform is preferred.

The measurement sample is not limited as long as there is a correlation between the halophenols and the dioxins, but there is a facility for incineration of general waste such as household waste and certain industrial wastes. Exhaust gas and incinerated ash discharged from coal. In the case of exhaust gas, the absorbing solution may be used as it is, or may be concentrated by a known method and then used as a measurement sample. If it is a general incinerator, it can be calculated by applying the correlation value between the halophenols concentration and the dioxin concentration that has already been published, but it is an incinerator that incinerates special waste. Alternatively, when the type of furnace is special, it can be calculated by preparing a relationship between the concentration of halophenols and the concentration of dioxins, for example, by preparing a calibration curve in advance.

[0015]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

Examples 1-4 First, 45.9 mg of AlQ3 was dissolved in 100 ml of chloroform to obtain a 1 mM solution. Dilute this 2
A μM solution was prepared. Similarly, 12.85 mg of 2-chlorophenol (2-CP), 16.3 mg of 3,5-
Dichlorophenol (3,5-DCP), and 19.7
5 mg of 2,4,6-trichlorophenol (2,4,
6-TCP) was dissolved in 100 ml of chloroform, respectively, to prepare a diluted solution of 2 μM. Next, 2 μM
3 ml of 2 μM chlorophenol solution and chloroform were added to 2 ml of the AlQ3 solution of
The mixture was mixed at a ratio of 0 ml to 2 ml, and the mixture was stirred at room temperature for 5 minutes, and the fluorescence intensity was measured. The measurement was performed with an excitation wavelength of 350 nm, a measurement wavelength of 516 nm, and a target of phenol (PhOH) (apparatus used: spectrofluorimeter F-3000 manufactured by Hitachi, Ltd.). Table 1 shows the results. In addition, the concentration in Table 1 shows the concentration of chlorophenols, and the unit is μM. When the measurement results were plotted, the intensity and the fluorescence intensity of all chlorophenols were almost linear, and it was confirmed that both showed a positive correlation.

[0017]

[Table 1]

At the same time, exhaust gas is sampled from the upper part of the smoke stack using the household garbage incinerator A, and dioxins (D / D) are measured by a usual measuring method (GC / MS analysis).
XN measurement) and chlorophenols were quantified by the method of the present invention to estimate the amount of dioxin (DXN conversion value). For chlorophenols, based on the results of the previous study, representative 2-chlorophenol and measured values of fluorescence intensity were used as calibration curves, and 2-chlorophenol (2-C
(P conversion value). The estimation of the amount of dioxin (DXN) from the amount of 2-chlorophenol (2-CP) is described in Masakatsu Hiraoka, "Generation and Control of Dioxins in Waste Treatment", Journal of the Japan Society of Waste Management 1 (1), page 24, 199
Conversion was performed using the correlation diagram described in FIG. Table 2 shows the results. According to this, it was recognized that the amount of dioxin and the amount of 2-chlorophenol (fluorescence intensity) showed a positive correlation.

[0019]

[Table 2]

[0020]

According to the method of the present invention, chlorophenols in exhaust gas generated by incineration of municipal waste and industrial waste can be easily measured, and inexpensive and rapid quantification of dioxins becomes possible.

Claims (4)

[Claims] 1. A sample in which a metal complex of 8-oxyquinoline and a sample whose dioxins are to be measured are mixed with a halogen-containing organic solvent, and the mixture is irradiated with excitation light and the fluorescence intensity is measured. A method for measuring dioxins, characterized by quantifying halophenols having a concentration correlation with dioxins contained therein and estimating the concentration of dioxins from the concentration of the halophenols. 2. The method for measuring dioxins according to claim 1, wherein the metal complex of 8-oxyquinoline is tris (8-quinolinolate) aluminum (III), and the organic solvent containing halogen is chloroform. 3. The method for measuring dioxins according to claim 1, wherein the halophenol is a chlorophenol containing one or more chlorine atoms in the molecule. 4. The method for measuring dioxins according to claim 1, wherein the excitation light wavelength is 300 to 450 nm and the fluorescence wavelength is 450 to 600 nm.