JP5357598B2 - Analysis method of amines - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a method of analyzing amines that are generated from azo dyes or azo pigments and analyzes a larger number of types of amines with a high recovery. <P>SOLUTION: The method of analyzing amines is an analysis method of amines generated from azo dyes or azo pigments. The method of analyzing amines includes: an azo radical cleavage process for generating amines by cleaving azo radicals in the azo dyes or azo pigments; an amino radical protection process for protecting amino radicals in amines generated by cleavage of the azo radicals; and an analysis process for analyzing amines for protecting the amino radicals. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a method for analyzing amines produced from azo dyes or azo pigments.

  Azo dyes are widely used as colorants in various products. However, it is known that in such azo dyes, an azo group is reduced to produce a carcinogenic aromatic amine. For this reason, the various analysis methods of the said aromatic amine are reported (for example, refer nonpatent literature 1-5).

  In the above analysis method, the azo group in the azo dye is cleaved to form amines, and then these amines are analyzed.

M.C.Garrigos et al., J. Chromatogr. A 976 (2002), 309-317 Trends in Analytical Chemistry, Vol.24, No.1, 2005, 49-56 EN 14362-1: 2003 EN 14362-2: 2003 CEN ISO / TS 17234: 2003

  However, in the above conventional method, the amount of amine actually contained for specific amines cleaved from azo dyes or azo pigments (particularly 2,4-diaminoanisole, 4-methyl-m-phenylenediamine, etc.) Only a very small amount can be detected as compared with the case of 4-aminoazobenzene, and it is difficult to detect the cleavage product itself.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to provide amines capable of analyzing a greater variety of amines produced from azo dyes or azo pigments with a high recovery rate. To realize the analysis method.

  In order to solve the above-mentioned problems, the present inventor diligently found that 2,4-diaminoanisole and 4-methyl-m-phenylenediamine can detect only a very small amount compared to the amount of amines actually contained. Study was carried out. As a result, the present inventor considers that these specific amines are oxidized during the analytical operation, resulting in a decrease in the detection amount, and by protecting the amino groups of these amines, It was found that amines can be analyzed with high accuracy.

  Furthermore, by protecting amino groups of aniline and 1,4-phenylenediamine, which are cleavage products of 4-aminoazobenzene, these amines can be detected, and the content of 4-aminoazobenzene is indirectly analyzed. The present inventors have found that this can be done and have completed the present invention.

  That is, the amine analysis method according to the present invention is an analysis method of amines generated from an azo dye or an azo pigment in order to solve the above-described problem, and cleaves the azo group in the azo dye or azo pigment. An azo group cleavage step for producing an amine, an amino group protection step for protecting an amino group in the amine produced by the cleavage of the azo group, and an analysis step for analyzing the amine with the amino group protected It is characterized by that.

  According to the above method, since the amino group in the amines generated by the cleavage of the azo group is protected by the protection step, it is possible to suppress decomposition or the like during the analysis of specific amines that are easily oxidized. Therefore, there is an effect that more types of amines produced from the azo dye or the azo pigment can be analyzed with a high recovery rate.

  In the method for analyzing amines according to the present invention, the amino group protecting step is preferably performed by acylating the amino group.

  According to the above method, the amino group can be easily protected.

  In the method for analyzing amines according to the present invention, the amino group protecting step is preferably performed by acetylating the amino group.

  According to the above method, the amino group can be protected more easily.

  In the method for analyzing amines according to the present invention, the azo group cleavage step and the amino group protection step are preferably performed simultaneously.

  According to the above method, the period in which an unprotected amino group is present can be minimized, so that decomposition of amines during the analysis can be further suppressed. Therefore, there is a further effect that amines can be analyzed with higher accuracy.

  In the amine analysis method according to the present invention, the azo group cleavage step and the amino group protection step are performed by reacting an azo dye or an azo pigment with an organic acid and an organic acid anhydride in the presence of zinc. It is preferable.

  According to the said method, the said azo group cleavage process and the said protection process can be performed simply.

  As described above, the method for analyzing amines according to the present invention includes an azo group cleavage step, an amino group protection step, and an analysis step.

  For this reason, there exists an effect that many types of amines produced | generated from an azo dye or an azo pigment can be analyzed with a high recovery rate.

It is a graph which shows the analysis result of the reference examples 1 and 2. FIG.

  Hereinafter, an embodiment of the present invention will be described in detail.

  In the present specification, “A to B” indicating a range means that the range is A or more and B or less, and various physical properties mentioned in the present specification are in Examples described later unless otherwise specified. The value measured by the described method is meant.

  The method for analyzing amines according to the present embodiment is a method for analyzing amines produced from azo dyes or azo pigments, and cleaves azo groups in azo dyes or azo pigments to produce amines. A step, an amino group protecting step for protecting an amino group in amines generated by cleavage of the azo group, and an analyzing step for analyzing the amines protecting the amino group.

  In addition, an extraction step for extracting an azo dye or an azo pigment from the sample to be analyzed is included before the azo group cleavage step, and a purification step for purifying amines with amino group protection after the amino group protection step. Also good.

  In the present specification, “azo dye” means a dye having an azo group, and similarly, “azo pigment” means an azo pigment having an azo group.

(1) Extraction step The extraction step is a step of extracting an azo dye or azo pigment from a sample to be analyzed. Examples of samples to be analyzed include fibers and resins.

  Specific examples of the method for extracting the azo dye or the azo pigment include a method for extracting with an aqueous or organic solvent. Since not only the dye but also the pigment can be extracted, it is more preferable to extract with an organic solvent. In addition, extraction with an organic solvent can also extract a dye or pigment contained in the resin.

(2) Azo group cleavage step The azo group cleavage step is a step in which an azo group in an azo dye or azo pigment is cleaved to produce an amine.

Examples of the method for cleaving the azo group include (i) a method using sodium dithionite, (ii) a method using stannous chloride (SnCl ₂ ), (iii) a method using zinc powder and an organic acid, Is mentioned.

  The method (i) can be performed according to the method described in EN14362, for example. The method (ii) can be performed, for example, under the conditions described in the literature (Rolf F. Straub et. Al., Anal. Chem. 65 (1993), 2131-2136).

  The method (iii) can be performed according to the method described in the literature (S. Gowda et al., Tetrahedron Letters 43 (2002), 1329-1331), for example.

  “As R in the organic acid RCOOH used in the above method (iii), a substituted or unsubstituted alkyl group is preferable. Specific examples of the organic acid RCOOH include formic acid, acetic acid, propionic acid, butyric acid, trifluoroacetic acid and the like. Is mentioned.

  In the method (iii), when formic acid is used as the organic acid, it can be performed only by cleaving the azo group.

  On the other hand, when an organic acid containing an alkyl group is used and an organic acid anhydride is used in combination, the azo group is cleaved and the amino group of the amine to be purified is converted to an acyl group containing the alkyl group ( RCO-) can be acylated. In other words, this case is more preferable because an amino group protecting step described later can be performed at the same time. In addition, when using together an organic acid anhydride, it is preferable that the alkyl group of an organic acid anhydride is the same as the said alkyl group of an organic acid.

  In the method (iii), the cleavage reaction can proceed in an organic solvent. For this reason, even if the azo dye or azo pigment is extracted with an organic solvent, the extract can be used as it is in the azo group cleavage step without any special treatment.

(3) Amino group protection step The amino group protection step is a step of protecting an amino group in amines generated by cleavage of the azo group.

  Examples of the method for protecting the amino group include a method for acylating an amino group, a method for benzoylation, a method for silylation, a method for producing a Schiff base, and a method for alkylation.

Examples of the acylating agent that can be used in the acylating method include various carboxylic acid derivatives such as carboxylic acid anhydride (R′CO) ₂ O and acyl halide R′COX ′ (provided that, in each chemical formula, R ′ Is an alkyl group, and X ′ is a halogen atom.

  R ′ in the various carboxylic acid derivatives is preferably a substituted or unsubstituted alkyl group. The substituted alkyl group is an alkyl group in which at least one hydrogen atom constituting the alkyl group is substituted with another atom, and examples thereof include a trifluoromethyl group.

  By acylating with the acylating agent, an R′CO group can be introduced into the amino group of amines.

(4) Purification step The purification step is a step of purifying the amines with the amino group protected. The amines with the amino group protected may be subjected to the analysis step described later without purification, but the purification step is preferably performed from the viewpoint of performing analysis with higher accuracy.

  Examples of the purification method include extraction by liquid separation operation, etc., dehydration, evaporation of solvent removal, and various chromatography such as column chromatography.

(5) Analysis step The analysis step is a step of analyzing amines with the amino group protected. Analyzes of amines with amino groups protected include liquid chromatography such as gas chromatography and high performance liquid chromatography (HPLC), and gas chromatography / mass spectrometry (GC-MS) combining these with mass spectrometry. ), Liquid chromatography / mass spectrometry (LC-MS, LC-MS / MS) and the like.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to a following example.

<Analysis results using amine standard solution>
[Reference Example 1]
To 10 mL of an acetonitrile / acetic acid / acetic anhydride (7: 2: 1 by volume) solution, 1 g of zinc powder and 300 μL of a standard solution each containing 10 μg of each amine shown in Table 1 were added, and the mixture was placed in a hot water bath. The mixture was reacted at about 50 ° C. for 30 minutes by applying ultrasonic waves. Thereafter, each amine in the reaction solution was quantified by LC-MS / MS. The results are shown in FIG. The compound names in FIG. 1 correspond to Table 1 below.

In addition, the “recovery rate” in FIG.
Recovery rate (%) = (quantitative amine content) / (amine content in standard solution) × 100
It is represented by

[Reference Example 2]
Using the standard solution containing each amine used in Reference Example 1, each amine was quantified by the method of EN 14362. The results are shown in FIG.

  As shown in FIG. 1, it was confirmed that the result of Reference Example 1 can be analyzed with an extremely high recovery rate as compared with the result of Reference Example 2. This is presumably because the amine of each amine was decomposed by oxidation or the like because the amino group of each amine was not protected in the method of Reference Example 2.

<Analysis results using dye and pigment standard solutions>
[Example 1]
To 10 mL of acetonitrile / acetic acid / acetic anhydride (7: 2: 1 by volume) solution, add 1 g of zinc powder and 100 μL of a dye pigment standard solution containing 30 μg of each dye and pigment shown in Table 2 (in terms of generated amine). The mixture was reacted at about 50 ° C. for 30 minutes by applying ultrasonic waves in a hot water bath. Thereafter, each amine in the reaction solution was quantified by LC-MS / MS. The results are shown in Table 3.

"Recovery rate" in Table 3 is
Recovery rate (%) = (quantitative amine content) / (theoretical amount of amines produced from dye pigment standard solution) × 100
It is represented by

[Comparative Example 1]
Each amine was quantified by the method of EN 14362 using the dye pigment standard solution used in Example 1. The results are shown in Table 3.

  As shown in Table 3, it was confirmed that the method of Example 1 can be analyzed with an extremely high recovery rate as compared with the method of Comparative Example 1. This is presumably because, in the method of Comparative Example 1, the amino group of each amine was not protected, so that each amine was decomposed by oxidation or the like during the analysis.

<Analytical result of polystyrene using dye standard solution>
[Example 2]
30 μg of each dye shown in Table 4 (in terms of generated amine) was dissolved in 3 g of polystyrene (using a commercial industrial product), kneaded, and then desolvated to prepare a sample.

  Acetic acid and acetic anhydride are added to 0.1 g of the above dye-containing polystyrene so as to be an acetonitrile / acetic acid / acetic anhydride (7: 2: 1 by volume ratio) solution, and 1 g of zinc powder is further added, and the mixture is added. Extraction and reaction were performed at about 50 ° C. for 45 minutes by applying ultrasonic waves in a hot water bath. Thereafter, each amine in the reaction solution was quantified by LC-MS / MS. The results are shown in Table 4.

The “recovery rate” in Table 4 is
Recovery rate (%) = (quantitative amine content) / (theoretical amount of amines produced from dye standard solution) × 100
It is represented by

[Comparative Example 2]
Using the sample prepared in Example 2 in which the dye was kneaded with the dye, the dye was extracted with water according to the method of EN 14362, and each amine was quantified. The results are shown in Table 4.

[Comparative Example 3]
Each amine was quantified in the same manner as in Comparative Example 2 except that the dye was extracted with acetonitrile instead of water. The results are shown in Table 4.

[Comparative Example 4]
Each amine was quantified in the same manner as in Comparative Example 2 except that the dye was extracted with acetone instead of water. The results are shown in Table 4.

  As shown in Table 4, it was confirmed that the method of Example 2 can be analyzed with an extremely high recovery rate as compared with the methods of Comparative Examples 2 to 4. This is probably because the methods of Comparative Examples 2 to 4 did not protect the amino group of each amine, and therefore were decomposed by oxidation or the like. In particular, in the method of Comparative Example 2, since extraction was performed with water, it was considered that analysis of all amines could not be performed because the dye could not be recovered from the resin.

  In Table 4, “-” means that there is no data.

<Results of polystyrene analysis using pigment standard solution>
Example 3
30 μg of each pigment shown in Table 5 was dissolved in 3 g of polystyrene (using a commercial industrial product) in a solvent, kneaded, and then desolvated to prepare a sample.

  Acetic acid and acetic anhydride are added to 0.1 g of the above dye-containing polystyrene so as to be an acetonitrile / acetic acid / acetic anhydride (7: 2: 1 by volume ratio) solution, and 1 g of zinc powder is further added, and the mixture is added. The mixture was reacted at about 50 ° C. for 30 minutes by applying ultrasonic waves in a hot water bath. Thereafter, each amine in the reaction solution was quantified by GC-MS. The results are shown in Table 5.

The “recovery rate” in Table 5 is
Recovery rate (%) = (quantified amine content) / (theoretical amount of amines produced from pigment standard solution) × 100
It is represented by

[Comparative Example 5]
Using the sample prepared in Example 3 in which the pigment was kneaded with the pigment, the pigment was extracted with water according to the method of EN 14362, and each amine was quantified. The results are shown in Table 5.

[Comparative Example 6]
Each amine was quantified in the same manner as in Comparative Example 5 except that the pigment was extracted with acetonitrile instead of water. The results are shown in Table 5.

[Comparative Example 7]
Each amine was quantified in the same manner as in Comparative Example 5 except that the pigment was extracted with acetone instead of water. The results are shown in Table 5.

  As shown in Table 5, it was confirmed that the method of Example 3 can be analyzed with an extremely high recovery rate as compared with the methods of Comparative Examples 5 to 7. This is probably because the methods of Comparative Examples 2 to 4 did not protect the amino group of each amine, and therefore were decomposed by oxidation or the like. In particular, in the method of Comparative Example 5, since extraction was performed with water, it was considered that analysis of all amines could not be performed because the dye could not be recovered from the resin.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The amine analysis method of the present invention can analyze amines with higher accuracy. For this reason, it can be suitably used in various fields where azo dyes or azo pigments are used.

Claims (3)

A method for analyzing amines produced from an azo dye or an azo pigment,
An azo group cleavage step of cleaving the azo group in the azo dye or azo pigment to produce amines;
An amino group protecting step for protecting an amino group in amines generated by cleavage of the azo group;
An analysis step of analyzing amines with the amino group protected;
Including
At the same time it has the row and the azo group cleavage step and the amino group protection step,
The amino group protecting step is performed by acylating the amino group,
The azo group cleavage step and the amino group protection step are performed by reacting an azo dye or an azo pigment with an organic acid and an organic acid anhydride in the presence of zinc,
The method for analyzing amines, wherein the organic acid contains a substituted or unsubstituted alkyl group . 2. The method for analyzing amines according to claim 1 , wherein the organic acid and the organic acid anhydride contain the same alkyl group. The method for analyzing amines according to claim 1 or 2, wherein the alkyl group is a methyl group.

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