KR100812978B1 - Filler containing active carbon for analysis of dioxin and the like - Google Patents

Abstract

Provided is a filler for dioxins analysis and cleaning that has excellent separation ability and does not require cleaning with an organic solvent.

The filler for cleaning up dioxin analysis, characterized in that the powder containing activated carbon and silica gel treated with a low oxygen atmosphere.

Description

Filler containing active carbon for analysis of dioxin and the like}

1 is a dissolution graph of 1, 3, 6, and 8-TCDD in Example 1 (360 占 폚 x 1h heat treated product).

2 is a dissolution graph of OCDF in Example 1 (360 占 폚 x 1h heat treated product).

3 is an elution graph of 1, 3, 6, and 8-TCDD in Example 2 (380 ° C × 1h heat treated product).

4 is a dissolution graph of OCDF in Example 2 (380 占 폚 x 1h heat treated product).

FIG. 5 is a dissolution graph of 1, 3, 6, and 8-TCDD in Example 3 (400 占 폚 x 1h heat treated product). FIG.

6 is a dissolution graph of OCDF in Example 3 (400 占 폚 x 1h heat treated product).

7 is a dissolution graph of 1, 3, 6, and 8-TCDD in Example 4 (420 ° C. × 1 h heat treated product).

8 is a dissolution graph of OCDF in Example 4 (420 ° C. × 1 h heat treated product).

The present invention relates to fillers used in cleanup processes for dioxin analysis.

Generally, dioxins are a general term for polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF) and coplanar PCB, and many isomers are contained in it. In recent years, these dioxins have been found to be largely dispersed in the atmosphere even by incineration of industrial wastes and the like, which is a major social problem. To

In the analytical sample dioxins, existing amount of dioxins are ^{ppb-ppq (10 -9 ~10 -15} ) and a very small amount at a level, which is in most cases co-exist a number of different organic compounds. Therefore, in order to separate and quantify with high accuracy, it is necessary to remove compounds which interfere with or adversely affect the analysis of dioxins in a step before measurement with a gas chromatograph (GC) / mass spectrometer (MS) by a clean-up operation.

As a filler for cleaning up used in such a clean-up operation, the filler which contained activated carbon in silica gel etc. which used the activated carbon property which adsorb | sucks the plate-like structure specifically like dioxins is recognized, and this is the dioxins and others. Isolate organic compounds. For example, after loading a sample solution to a column filled with activated carbon-containing filler, firstly, hexane is passed through this fraction to elute the general organic compound, and then toluene is passed through the column to give this fraction. It is possible to separate (fractionate) by eluting dioxins. The characteristics that the activated carbon-containing filler should include include excellent dispersibility, high recovery of dioxins, and non-contamination by analytical disturbance components other than dioxins. Specifically, activated carbon buried silica gel (Japanese Patent Laid-Open No. 7-50084) obtained by reacting a mixture of sodium silicate (water glass) and activated carbon with a photoacid is recognized. However, this method is complicated and requires a high degree of reaction control technique in order to make the physical properties of the resulting filler constant.

Moreover, activated carbon dispersion silica gel (T. Wakimoto, et al, Chemosphere, 27 , 2117-2122 (1993)) obtained by mixing activated carbon and silica gel is recognized. This method is simple in manufacturing and has excellent characteristics in terms of reproducibility of properties and manufacturing cost, but it takes a long time to remove contaminants by pretreatment.

As a similar product of activated carbon buried silica gel, carbon molecular sieve (available from the 7th Environmental Chemistry Discussion Conference Collection, 154 (1998), Sigma Aldrich Japan) is recognized. However, this has a drawback in that the recovery rate of dioxins is low, and the heating of toluene (about 50 ° C.) and the elution by the reverse distillation method are required.

In any of the above-mentioned activated carbon store silica gel, activated carbon dispersed silica gel and carbon molecular sieve, in order to use the filler for the clean-up operation, for example, [Methods for Measuring Hazardous Air Pollutants (Dioxins and Coplanar PCBs)] ( As described in the EPA, March 11, 2015, it is necessary to sufficiently wash with an organic solvent such as toluene and to remove dioxins and other analytical disturbances originally contained in activated carbon and silica gel constituting the filler.

It goes without saying that reliable data cannot be obtained if fillers that are contaminated with analytical disturbances such as dioxins are used.

Alumina can also be used as a filler for dioxin analysis, and it is dried for 18 hours at 130 ° C for activation (Hazardous Air Pollutant Measurement Manual (Dioxins and Coplanner PCBs)) In order to volatilize the dioxins adsorbed on alumina, and to activate (dry) and alumina, it is known to heat-treat at a temperature of 500-600 ° C for 24 hours (March 11, Pharmacia). Pharmacia), 441 (1998), Nai Chuo, Industry and Environment, 41 (1998). However, since this method is not intended to decompose dioxins, dioxins may remain in alumina.

As described above, the conventional alumina and activated carbon-containing fillers are contaminated with dioxins and other analytical hindrance components. Therefore, the fillers must be sufficiently washed with an organic solvent such as toluene before the clean-up operation.

By the way, as a washing method with an organic solvent such as toluene, a soxlay extraction method (for example, [Method for analyzing and measuring dioxins and coplanar PCBs in blood]) (Ministry of Health, 29th Japanese Environmental Chemistry Society Lecture) Preliminary Proceedings (1999), T. Wakimoto, et al, Chemosphere, 27 , 2117-2122 (1993)) or ultrasonic cleaning (e.g., 松 村, Journal of Water and Environment, 21 , 412-416 (1998)). This Soxhley extraction method typically requires 16-24 hours of long extraction (eg T. Wakimoto, et al, Chemosphere, 27 , 2117-2122 (1993)), and When used for the analysis of samples with low dioxin concentrations, a filler that has been subjected to Soxhlay extraction for at least one week is required (for example, Kisaki Sako et al., Eighth Environmental Chemistry Conference Collection, 216 (1999)). After washing, the organic solvent is removed by a method such as vacuum drying with a rotary evaporator. Since the activated carbon and the silica gel constituting the filler are porous bodies, long-term drying under reduced pressure is necessary to remove the organic solvent that has entered the small pores.

The problems of the conventional method are summarized as follows.

① It takes a long time to clean the filler.

(2) If it is insufficient to remove organic solvents such as toluene from the filler, and the organic solvent remains in the filler, the separation ability of the filler is significantly reduced, and dioxins are difficult to separate.

③ Organic solvents, such as toluene, are used to clean the filler. This organic solvent is harmful to the human body and may adversely affect the health and environment of workers.

As a related technique, a method of heat-treating 300-500 ° C. in a low oxygen atmosphere has been recognized for the dioxins decomposition method contained in the fumes or ashes emitted from municipal waste incinerators (eg, Shida Hi et al.). , 3rd Waste Society Research Conference, 355 (1992), Yeung-Sung et al., Global Environment, 10 , 14 (1999)). In addition, a method is known in which activated carbon adsorbed dioxin in exhaust gas is heated in a low oxygen atmosphere to decompose dioxin adsorbed to regenerate activated carbon (JP-A-5-301022, JP-A-11). -76756 and Japanese Patent Laid-Open No. 11-114374. However, the use of dioxins pyrolysis in a low oxygen atmosphere is limited to dioxins emission reduction and activated carbon regeneration in municipal waste incineration plants, and requires high characteristics such as dispersion capacity and ultra trace component detection. There is no example used for the washing | cleaning of the dioxins-type analysis cleanup filler, and the effect by it is not examined at all.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a filler for dioxins analysis and cleanup, which has excellent dispersibility and does not require washing with an organic solvent.

MEANS TO SOLVE THE PROBLEM The present inventors discovered the method of solving the said subject with the dioxins analysis cleanup filler obtained by heat-treating activated carbon and a silica gel powder in a low oxygen atmosphere, in order to solve the said subject, and completed the present invention. Reached.

That is, the present invention relates to a filler for cleaning up for dioxin analysis, wherein the filler comprising activated carbon and silica gel is heat-treated in a low oxygen atmosphere.

Moreover, this invention relates to the said filler characterized by the heat processing temperature being 300-500 degreeC.

And this invention relates to the said filler characterized by the low oxygen atmosphere being atmosphere of 5% or less of oxygen concentration.

The present invention further relates to the above filler, characterized in that the powder is essentially a powder consisting of activated carbon having a molecular diameter of 75 µm or less and silica gel having a molecular diameter of 50-500 µm.

EMBODIMENT OF THE INVENTION Below, the Example of this invention is described.

The filler according to the present invention adds activated carbon that has been sized to the sized silica gel, mixes uniformly, heat-treats the powder in a nitrogen stream, and heats the glass wool glass tube with GLASS WOOL, anhydrous sodium sulfate, The activated carbon-containing filler and anhydrous sodium sulfate are laminated to prepare a glass to be used.

Although there are no particular restrictions on the type and shape of the activated carbon used in the production, the particle diameter thereof is determined in consideration of the dispersibility of activated carbon when mixed with silica gel, and is preferably 75 μm or less, particularly preferably 38 μm or less. It is a particle diameter.

There is no particular restriction on the type and shape of the silica gel, but the particle size thereof is determined in consideration of the liquid permeability of the column, the dispersibility of the activated carbon when mixed with the activated carbon, and is preferably 50 to 500 µm, particularly preferably 100-250 μm.

In the production of the filler according to the present invention, the content of activated carbon may be high, especially when TeCDDs and TeCDF, which are tetrachlorine dioxins, are eluted with 25% (v / v) dichloromethane-containing hexane fractions. In this case, since the recovery rate of dioxins tends to decrease, it is determined in consideration of the dispersing capacity and the like, but is preferably in the range of 1-3%, particularly 1.5% -2.5%, based on the weight of the silica gel.

The heat treatment temperature of the filler according to the present invention is determined in consideration of the decomposition efficiency of dioxins, the separation ability of the filler, and the like, and the heat treatment is performed at a temperature of 300-500 ° C. In particular, a heat treatment temperature of 350-450 ° C is preferred.

The heat treatment storage time is determined in consideration of the decomposition of dioxins, etc., preferably 10 minutes or more, and particularly preferably 30 minutes-2 hours.

In the present invention, the atmospheric gas oxygen concentration during heat treatment is determined in consideration of the decomposition efficiency of dioxins, etc., preferably 5% or less, and particularly preferably 1% or less. In addition, when the heat treatment of the activated carbon-containing filler is carried out, the powder can be left to perform the transfer. Preferably, the powder is stirred while the powder is stirred to increase the decomposition efficiency of dioxins.

The process of heat-treating in a low oxygen atmosphere is not limited after mixing activated carbon, a silica gel, etc., It is also possible to heat-treat an activated carbon and a silica gel each independently in a low oxygen atmosphere, and to mix it after that.

In the present invention, the components of the activated carbon-containing filler are not limited to activated carbon and silica gel, and other components may be contained as long as the effects of the filler according to the present invention are not impaired or improved.

EXAMPLE

Although an Example and a comparative example demonstrate this invention concretely below, this invention is not limited to this.

Example 1-4

(1) the structure of the filler

To 100 g of silica gel (Kanto Chemical Co., Ltd.) sized at 106-250 μm in a sieve (SIEVE, Furui), 2 g of activated carbon (Taihei Chemical Industry Co., Ltd.) sized at less than 38 μm was added, mixed uniformly, Activated carbon dispersed silica gel. This powder was heat-treated in nitrogen stream. Table 1 shows the heat treatment conditions.

Table 1 Heat Treatment Conditions of Activated Carbon Dispersed Silica Gel Heat treatment condition atmosphere Nitrogen Gas Flow Rate Example 1    360 ℃ × 1h          nitrogen       500ml / min Example 2    380 ℃ × 1h Example 3    400 ℃ × 1h Example 4    420 ℃ × 1h

(2) Column production

A glass wool, anhydrous sodium sulfate, about 10mm, activated carbon dispersion silica gel 1g, and anhydrous sodium sulfate about 10mm were laminated | stacked on the glass column chromatographic tube of internal diameter 10mm and length 250mm, and the column was produced.

(3) blank test

100 ml of 25% (v / v) dichloromethane-containing hexane was added, followed by 20 ml of toluene, and each eluate was concentrated to 100 µl. HRGC (Hewlett Packard 5890Ⅰ) -HRMS (JEOL SX-102A) Using the SIM method, the dioxins (TeCDDs, PeCDDs, HxCDDs, HpCDDs, OCDD, TeCDFs, PeCDFs, HxCDFs, HpCDFs, OCDF) were blank-checked. 2 μl of sample solution was injected and measured. As a comparative example, the blank test of the activated carbon-containing filler which was not heat-treated by nitrogen atmosphere was also included. The results are shown in Table 2. Moreover, the case where the peak S / N ratio was 2 or less was made into the lower limit of detection, and it described as N.D. (Not Detected) in the table.

Table 2 Detection amount of dioxin in blank test Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Heat treatment product 360 ℃ × 1h Heat treatment product 380 ℃ × 1h Heat Treatment Product 400 ℃ × 1h Heat treated product 420 ℃ × 1h Unheated products DCM / Hex Fraction (pg) toluene                                                  Fraction (pg) DCM / Hex Fraction (pg) toluene                                                  Fraction (pg) DCM / Hex Fraction (pg) toluene                                                  Fraction (pg) DCM / Hex Fraction (pg) toluene                                                  Fraction (pg) DCM / Hex Fraction (pg) toluene                                                  Fraction (pg) Dioxins detection N.D. N.D. N.D. N.D. N.D. N.D. N.D. N.D. N.D. 0.3pg detection of TeCDFs

Note) In the table, DCM / Hex means 25% (v / v) dichloromethane-containing hexane.

    Dioxins to be detected and the lower detection limit (pg) thereof are as follows.

TeCDDs: 0.1

PeCDDs: 0.1

HxCDDs: 0.2

HpCDDs: 0.2

OCDD: 0.5

TeCDFs: 0.1

PeCDFs: 0.1

HxCDFs: 0.2

HpCDFs: 0.2

OCDFs: 0.5

From the blank test results, it can be seen that the activated carbon-containing filler heat-treated at a temperature range of 360 ° C to 420 ° C in the nitrogen stream does not contain dioxins. On the other hand, dioxins were included in the activated carbon-containing fillings which were not heat-treated with the nitrogen atmosphere of the comparative example.

(4) separation test

0.5 mL of sample solution containing 1, 3, 6, 8-TCDD, 1, 3, 7, 9-TCDD, OCDF (including 1 ppm) was loaded into the column. Next, 200 ml (20 ml x 10 fractions) of hexane containing 25% (v / v) dichloromethane and 300 ml (20 ml x 15 fractions) of toluene were added to concentrate the eluate, and HRGC (Hewlett Packard 5890I) -HRMS ( JEOL SX-102A) was used to analyze by SIM method, and dilution patterns of dioxins were adjusted.

As a result of the separation test using activated carbon-containing fillers heat-treated at a temperature range of 360 ° C. to 420 ° C. in a nitrogen stream, dioxins were not eluted in the fraction of hexane containing 25% (v / v) dichloromethane, but dioxins were recovered in the toluene fraction. It eluted (FIGS. 1-8). Thus, it can be seen that the activated carbon-containing filler according to the present invention heat-treated at a temperature range of 360 ° C to 420 ° C in a nitrogen stream has excellent separation ability.

It is possible to decompose and remove dioxins with an activated carbon-containing filler by heat-treating powder containing activated carbon and silica gel in a low oxygen atmosphere for about one hour. As a result, since the washing | cleaning by organic solvents, such as toluene, is unnecessary, the said subject can be solved. By heat treatment at low temperature, it is possible to prevent damage to the activated carbon-containing filler and to impart excellent separation ability.

Claims (10)

delete delete delete delete delete delete delete delete delete A method of preparing a filler for cleaning up for dioxin analysis, comprising a step of heat-treating a powder containing activated carbon and silica gel in a low oxygen atmosphere.

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