JP3285832B2 - Highly sensitive analysis method for dioxins - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a capillary electric device.
Simple and quick measurement of dioxin concentration by electrophoresis
Of sensitive dioxin analysis methods
You.

[0002]

2. Description of the Related Art Analysis of hydrophobic organic compounds represented by, for example, polychlorinated dibenzodioxins and polychlorinated dibenzofurans, and analysis of, for example, phenylalanine, valine, methionine, and alanine. Conventionally, liquid chromatography has been used for amino acid analysis.

[0003] However, in the conventional analysis using liquid chromatography, the influence of coexisting substances is large due to low separation performance, and complicated pretreatment operations for removing interfering components and a high-performance mass spectrometer are required. Since the cost and the analysis time are greatly increased, a simpler analysis method has been desired.

[0004] Capillary electrophoresis is known to have extremely high separation performance. For example, urea, β-cyclodextrin, sodium dodecyl sulfate (SDS) and the like are added to a buffer solution and neutral to alkaline conditions. so,
For example, it has been proposed to analyze optical isomers of L-type and D-type amino acids (JP-A-8-114575). By using this method, the structural isomer analysis of a hydrophobic organic compound can be easily performed, but the analysis sensitivity is low (the lower limit of detection is about 10 ppm), so it is effective for the effective analysis of harmful components in environmental samples. It was difficult to apply.

Here, harmful components in environmental samples include:
For example, it is contained in exhaust gas discharged from various incinerators such as municipal garbage incinerators, industrial waste incinerators, and sludge incinerators. And harmful substances such as harmful chlorinated aromatic compounds typified by PCBs and aromatic hydrocarbons with a high degree of condensation, which are also referred to as so-called environmental hormones. Here, the dioxins are a general term for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), and are said to be generated in trace amounts when chlorine-based compounds and certain organic chlorine compounds are burned. Are chemically colorless crystals. There are 75 types of PCDDs and 135 types of PCDFs, depending on the number of chlorines, from monochloride to octachloride. Of these, dibenzo-p-dioxin tetrachloride (T ₄ CDD) is the most common. It is known to be highly toxic.

[0006] Dioxins are not limited to the above exhaust gas,
It may be contained in factory wastewater, incinerated ash, and landfill soil. The concentration of these dioxins is very small, and it is desired to establish a highly sensitive analytical method. For example, the “Manual for Standard Measurement and Analysis of Dioxins in Waste Disposal” (Waste Research Foundation, published in March 1997) has been enacted. In this official method, a high-resolution gas chromatography mass spectrometer (High Resolution GC / M
S apparatus) to perform quantitative analysis.

On the other hand, the demand for analysis of dioxins has been increasing in recent years, and rapid analysis has been demanded. When determining whether or not dioxins are present in the analysis target, it is not necessary to obtain data up to the toxic equivalents (TEx) of dioxins using a high-resolution GC / MS device. In such a case, it is desired to establish an analysis method that is simple and allows the analysis result to be quickly found.

In view of the above problems, the present invention provides a highly sensitive method for analyzing dioxins by capillary electrophoresis by examining the composition of the electrophoresis solution, the analysis conditions, and the operating procedure in capillary electrophoresis. It is in.

[0009]

Means for Solving the Problems To solve the above-mentioned problems, the invention of claim 1 uses an electrophoresis solution containing an acidic buffer, cyclodextrin, urea, and sodium dodecyl sulfate (SDS), and It is characterized in that homologs of dioxins are analyzed by capillary electrophoresis.

The invention of claim 2 is characterized in that, in claim 1, the cyclodextrin is any one of β-cyclodextrin and γ-cyclodextrin, or a mixture thereof.

[0011] The invention of claim 3 is characterized in that, in claim 1, a liquid having a lower conductivity than the electrophoresis liquid is used for concentrating the sample in the capillary.

The invention according to claim 4 is characterized in that, in claim 3, the liquid having low conductivity is obtained by adding pure water or an electrophoresis running solution to pure water.

[0013] The invention of claim 5 is characterized in that, in claim 1, the acidic buffer is at least one selected from weakly acidic solutions such as boric acid, phosphoric acid, citric acid and acetic acid.

The invention of claim 6 is characterized in that, in claim 1, the pH of the acidic buffer is 2 to 4.

The invention of claim 7 is characterized in that, in claim 1, before the sample liquid is injected into the capillary, a liquid having a lower conductivity than the acidic buffer is injected.

The invention of claim 8 is characterized in that, in claim 1, an acidic buffer is added to the sample solution.

According to a ninth aspect of the present invention, in the first aspect, the end portion is immersed in an acidic electrophoretic solution disposed at both ends, and the capillary through which the acidic electrophoretic solution passes and the inside of the electrophoretic solution at both ends are provided. And electrophoresis is performed from a power supply for applying a voltage with the electrophoresis start side as a cathode and the electrophoresis end side as an anode.

According to a tenth aspect of the present invention, in the ninth aspect, the means for detecting the sample separated by the capillary electrophoresis is any one of a fluorometer, an absorptiometer, and a mass spectrometer. I do.

The invention of claim 11 is characterized in that, in claim 1, the homologues of dioxins to be analyzed are polychlorinated dibenzofuran compounds and polychlorinated dibenzodioxin compounds.

[0020]

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

[0021] da by capillary electrophoresis method of the present invention
A high-sensitivity analysis method for homologues of ioxins is to analyze a sample of an electrophoretic substance by capillary electrophoresis using an electrophoresis solution containing an acidic buffer, cyclodextrin, urea, and sodium dodecyl sulfate (SDS). .

FIG. 1 shows an apparatus for performing the capillary electrophoresis. FIG. 1 is a schematic diagram of a high-sensitivity analyzer for dioxins . As shown in FIG. 1, a high-sensitivity dioxin analyzer for embodying the present invention has an end immersed in an acidic electrophoretic solution 11 provided at both ends, and the electrophoretic solution 1
And the electrophoresis liquids 11 at both ends,
A high-voltage power supply 14 for applying a high voltage with a platinum start electrode as a cathode (-) and an electrophoretic end side as an anode (+), and a final end of the capillary 12 are provided. And a detector 16 for detecting dioxins in a sample solution 15 which is an object to be electrophoresed in the capillary 12 and analyzing dioxins by capillary electrophoresis.

Here, the acidic electrophoresis liquid 11 is a mixture of, for example, an acidic buffer, cyclodextrin, urea, and sodium dodecyl sulfate (SDS). The acidic buffer constituting the acidic electrophoresis liquid 11 is, for example, boric acid,
It is at least one selected from weakly acidic solutions such as phosphoric acid, citric acid, and acetic acid.

As an example of the electrophoresis running solution used in the present invention, p
H is 2-4, an acidic buffer having a concentration of 30-100 mM, γ-cyclodextrin having a concentration of 30-50 mM,
Urea having a concentration of 3 to 6 M and sodium dodecyl sulfate (SDS) having a concentration of 50 to 150 mM are appropriately blended according to the separation target.

The diode in the sample 15 in the analyzer
To analyze the toxins, in order to improve the analysis accuracy, the dioxin in the sample is injected by injecting a concentrate 17 having a lower conductivity than the acidic buffer before injecting the sample into the capillary. and so as to concentrate the like.

In order to carry out the above-mentioned concentration operation, in the analysis method of the present invention, the electrode of the applied voltage of the electrophoresis apparatus is oriented in the opposite direction to the normal direction (the electrophoresis start side is a cathode (-), and the detector 16 is provided). The electrophoresis end side is referred to as the anode (+).) This is the reverse of the procedure for concentrating the sample and moving an analyte in the sample to be injected later to the interface between the concentrate and the electrophoretic solution to be injected into the capillary 12. If the electrophoresis start side is an anode (+) and the electrophoresis end side is a cathode (-) as usual, concentration does not occur at all, and the present invention cannot be carried out.

In the above concentration, it is preferable to use a liquid having a lower conductivity than the electrophoresis running liquid for the concentration of the sample in the capillary. As the liquid having a low conductivity, pure water is preferable, but other than pure water, a liquid obtained by adding an electrophoresis running solution to the pure water may be used. Although the ratio of the low conductivity is not particularly limited, the conductivity may be about 1/10 (lower by one digit or more) than the electrophoresis running solution.

In the present invention, the electrophoresis running solution is made acidic, but it is also an essential requirement of the present invention to make the electrophoresis running solution acidic. This is because if the electrophoresis running solution is not made acidic, the above-mentioned sample cannot be concentrated, which is not preferable. Here, the acidity of the electrophoresis running solution is preferably pH 2-4. This is less than pH 2, the separation is poor, whereas, if the pH exceeds 4, the sample diodes
This is because concentration of the toxins does not occur.

The detector is not particularly limited, but may be, for example, a spectrophotometer (ultraviolet absorption photometer, ultraviolet fluorometer) or a mass spectrometer. There is no particular limitation as long as it detects a sample.

As an example of the conditions for capillary electrophoresis in the present invention, when an ultraviolet absorption spectrophotometer is used as the detector 16, for example, the detection wavelength is 200 to 300 nm, and the applied voltage of the high voltage power supply 14 is 10 to 30 kV. , The effective capillary length of the capillary 12 is 50-100 μm.
Examples are those with m × 30 to 100 cm, but the present invention is not limited thereto.

The subject sensitive analytical method homologues of dioxins of the present invention is not particularly limited, polychlorinated dibenzofuran-based compound is suitable for use in analysis, such as polychlorinated dibenzodioxins compounds.

The cyclodextrin is preferably any one of β-cyclodextrin and γ-cyclodextrin, or a mixture thereof. In particular polychlorinated dibenzofuran-based compound, in the case of analysis of dioxins such as polychlorinated dibenzodioxins based compound, gamma
-Preferably cyclodextrin .

Next, an analysis method using the above apparatus will be described with reference to FIG. The electrophoresis running solution 11 is filled in the capillary 12 (see FIG. 2A). For this filling,
For example, the electrophoresis liquid 11 is filled in the capillary 12 by using a pressurizing method, a depressurizing method, or the like. Next, concentrate 1
7 is injected into the capillary 12 (see FIG. 2B). This injection is performed using, for example, the head method,
A predetermined amount of a concentrated liquid (pure water) 17 is injected into the capillary 12. Here, it is preferable that the injection amount of the concentrated liquid 17 be twice or more the amount of the sample liquid from the viewpoint of concentration efficiency. Next, the sample liquid 15 is injected into the capillary 12 (FIG. 2C).
reference). This injection is performed using, for example, a head method, and a predetermined amount of the sample liquid 15 is injected. Here, it is desirable to add the electrophoresis running solution to the sample solution 15 in advance at least three times the amount of the sample solution. This is because the separation performance can be improved by adding a buffer solution. The electrophoresis liquid 11 is placed at both ends of the capillary 12, and a high-voltage power supply (normal reverse direction: (+) on the detector side) 14 is applied thereto. The sample is instantaneously moved to the interface X between the sample and the electrophoresis running solution 11 to concentrate the sample (see FIG. 2D). After enrichment, continue with high voltage power supply 14
Is applied, electrophoretic separation is performed, and the analysis target is detected by the detector 16 (see FIG. 2E).

Next, the concentration procedure of the present invention will be described in detail with reference to FIG. A case in which, for example, three types (○, Δ, ×) of the analysis target are present in the sample liquid 15 will be described. Concentration Step 1 (Before Concentration) [See FIG. 3 (A)] As described above, the electrophoresis running solution 11 and the concentrating solution 17 have already been injected into the capillary 12, and the sample solution 15 is injected into the capillary 12. In this case, three types of samples are dispersed in the solvent of the sample solution. Concentration step 2 (during concentration) [see FIG. 3 (B)], concentration step 3 (concentration completed) [see FIG. 3 (C)] In the above state (A), when a voltage is applied to the high voltage power supply 14, the concentrated liquid Since the conductivity of the sample 17 is low, the moving speed of the sample in the sample solution 17 is increased, and the sample sample 18 is instantaneously moved to near the interface X between the sample solution 17 and the electrophoresis solution 11, thereby completing the sample concentration. Separation step [see FIG. 3 (D)] Thereafter, the concentrated sample 18 slowly migrates in the electrophoresis running solution 11 from the interface X, is separated in the electrophoresis running solution 11, and the separated samples 19 are subsequently detected by the detector 16 sequentially. You.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment showing the effects of the present invention will be described below, but the present invention is not limited to this.

Using the apparatus shown in FIG. 1, dibenzofuran, dibenzodioxin, 2,3-dichlorodibenzodioxin, 2,7-dibenzofuran, dibenzodioxin, 2,3-dichlorodibenzodioxin
Dichlorodibenzodioxin (2,7-dichlorodibenzodi
oxin), 2,3,7-trichlorodibenzodioxin
(2,3,7-trichlorodibenzodioxin) at a concentration of 2.5
A sample containing 1 ppm (solvent: 1,4-dioxane) was subjected to capillary electrophoresis. An ultraviolet absorption photometer (225 nm) was used as a detector.

As shown in FIG. 4, 2,7-dichlorodibenzodioxin (2,7-dichlorodibenzodioxin),
Dibenzodioxin, dibenzofuran, 2,3,7-trichlorodibenzodioxin (2,3,7-trichlorodibenzodioxin),
2,3-dichlorodibenzodioxin (2,3-dichlor
In the order of odibenzodioxin), five distinct peaks corresponding to each sample could be detected. Judging from the S / N ratio, it was found that it was possible to detect well up to 1/5 of these peak intensities, that is, as low as about 0.5 ppm. As a result, the sensitivity was improved by 10 to 20 times or more as compared with the conventional method.

[0038]

As described above, according to the first aspect of the present invention, an electrophoresis solution containing an acidic buffer, cyclodextrin, urea, and sodium dodecyl sulfate (SDS) is used.
Because homologues of dioxins in the electrophoresis are analyzed by capillary electrophoresis, the hydrophobic dioxins
Family analysis can be performed very simply, quickly and with high sensitivity by capillary electrophoresis. As a result,
Dioxins contained in environmental or biological samples
Applicable to analysis of tribes .

According to the second aspect of the present invention, in the first aspect, since the cyclodextrin is any one of β-cyclodextrin and γ-cyclodextrin or a mixture thereof, a homologue of a hydrophobic dioxin is used. body
Analysis, can be analyzed in a very simple and highly sensitive by capillary electrophoresis.

According to the third aspect of the present invention, in the first aspect, when the sample is concentrated in the capillary, a liquid having lower conductivity than the electrophoresis liquid is used, so that the concentration of the sample in the capillary is effective. Become a target.

According to the fourth aspect of the present invention, in the third aspect, since the liquid having a low conductivity is obtained by adding pure water or a running solution to pure water, concentration of the sample in the capillary is effective. Becomes

According to a fifth aspect of the present invention, in the first aspect, the acidic buffer comprises boric acid, phosphoric acid, citric acid,
Since it is at least one selected from a weakly acidic solution such as acetic acid , homologue analysis of hydrophobic dioxins can be extremely easily and highly sensitively analyzed by capillary electrophoresis.

According to the sixth aspect of the present invention, in the first aspect, since the pH of the acidic buffer is 2 to 4, the concentration and separation of the sample in the capillary becomes effective.

According to the seventh aspect of the present invention, in the first aspect, the liquid having a lower conductivity than the acidic buffer is injected before the sample liquid is injected into the capillary, so that the sample is concentrated in the capillary. Can be performed effectively.

According to the eighth aspect of the present invention, in the first aspect, an acidic buffer is added to the sample solution.
The concentration of the sample in the capillary is effective. It is characterized by the following.

According to the ninth aspect of the present invention, in the first aspect, a capillary having an end immersed in an acidic electrophoretic solution disposed at both ends to allow the acidic electrophoretic solution to pass therethrough, electrophoresis initiator with each placed comprising an electrode as the cathode in the liquid, since the capillary electrophoresis and a power source for applying a voltage to the termination of the electrophoresis side as an anode, hydrophobic diode
The analysis of homologues of toxins can be performed extremely simply and with high sensitivity by capillary electrophoresis.

According to the tenth aspect, the ninth aspect is provided.
In the above, since the means for detecting the sample separated by the capillary electrophoresis is any one of a fluorometer, an absorptiometer or a mass spectrometer , a homologue of a hydrophobic dioxin is used.
Body analysis can be performed very simply and with high sensitivity by capillary electrophoresis.

According to the invention of claim 11, claim 1 is
In the above, polychlorinated dibenzofuran compounds, polychlorinated dibenzodioxin compounds, phenylalanine compounds, valine compounds, methionine compounds and alanine can be separated and analyzed.

According to the invention of claim 12, claim 1 is
, Separation and analysis of homologues of dioxins can be easily performed. Further, unlike the liquid chromatography, there is no need to use an expensive apparatus or a large amount of separation solvent, so that the analysis cost can be reduced.

[Brief description of the drawings]

FIG. 1 shows a dioxy according to the present embodiment according to the present invention.
FIG. 2 is a schematic configuration diagram of a high-sensitivity analyzer for homologues of nitros .

FIG. 2 is a separation process diagram according to the embodiment of the present invention.

FIG. 3 is an enrichment step diagram according to the embodiment of the present invention.

FIG. 4 shows the results of analysis of dioxin homologs.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Electrophoresis liquid 12 Capillary 13 Platinum electrode 14 High voltage power supply 15 Sample liquid 16 Detector 17 Concentrate 18 Concentrate 18 Movement of concentrate 19 Separation sample

Continuation of the front page (72) Inventor Sumio Yamauchi 2-1-1 Shinhama, Arai-machi, Takasago-shi, Hyogo Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory (56) References JP-A-8-114575 (JP, A) JP-A-7 -306179 (JP, A) JP-A-6-186202 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 27/447 JICST file (JOIS)

Claims (11)

(57) [Claims] 1. A acidic buffer, using cyclodextrin, urea, electrophoresis solution containing sodium dodecyl sulfate (SDS), characterized in that the homologues of dioxins of the electrophoresis are analyzed by capillary electrophoresis Daioki
Highly sensitive method for analyzing synths . 2. The method according to claim 1, wherein the cyclodextrin is β-cyclodextrin, γ.
-A highly sensitive method for analyzing dioxins, wherein the method is any one of cyclodextrins or a mixture thereof. 3. The dioxin according to claim 1, wherein a liquid having a lower conductivity than the electrophoresis liquid is used for concentrating the sample in the capillary.
Class of sensitive analytical methods. 4. The high-sensitivity analysis method for dioxins according to claim 3, wherein the liquid having a low conductivity is obtained by adding pure water or a running solution to pure water. 5. The method of claim 1, said acidic buffer is boric acid, phosphoric acid, citric acid, highly sensitive analytical method for dioxins, characterized in that at least one selected from weakly acidic solution such as acetic acid. 6. The method according to claim 1, wherein the acidic buffer has a pH of 2 to 4.
Highly sensitive method for analyzing dioxins . 7. The die according to claim 1, wherein a liquid having a lower conductivity than an acidic buffer is injected before the sample liquid is injected into the capillary.
Highly sensitive method for analyzing oxins . 8. The method for high-sensitivity analysis of dioxins according to claim 1, wherein an acidic buffer is added to the sample solution. 9. The method according to claim 1, wherein the end is immersed in an acidic electrophoresis running solution disposed at both ends,
Performing capillary electrophoresis from a capillary through which an acidic electrophoresis running solution passes, and a power source that applies electrodes with electrophoresis starting side as cathode and electrophoresis ending side as anode while electrodes are arranged in electrophoresis running solution at both ends. Daioki characterized by
Highly sensitive method for analyzing synths . 10. The high-sensitivity analysis of dioxins according to claim 9, wherein the means for detecting the sample separated by the capillary electrophoresis is any one of a fluorometer, an absorptiometer, and a mass spectrometer. Method. 11. The method for high-sensitivity analysis of dioxins according to claim 1, wherein the homologues of dioxins to be analyzed are polychlorinated dibenzofuran compounds and polychlorinated dibenzodioxin compounds.