阅读说明：本技术 一种利用全二维气质联用仪检测焦油中含氮、硫化合物的方法 (Method for detecting nitrogen and sulfur compounds in tar by using full-two-dimensional gas chromatograph-mass spectrometer ) 是由 黄伟 刘建伟 张乾 梁丽彤 于 2019-12-02 设计创作，主要内容包括：本发明提供了一种利用全二维气质联用仪检测焦油中含氮、硫化合物的方法,属于焦油分析领域。本发明通过预编辑计算机语言,实现快速检测焦油中含氮、硫化合物。焦油中的含N化合物主要包括吡啶、喹啉、吲哚、咔唑、苯并喹啉、苯并咔唑以及各类型化合物的烷基取代物；含S化合物主要包括噻吩、苯并噻吩、二苯并噻吩以及各类型化合物的烷基取代物,由于同一类型化合物的同分异构体具有相同或相似的质谱数据,通过类举法,根据不同的含N、S化合物的质谱数据,预编辑计算机语言,描述其质谱特征,然后利用此语言在全二维色谱图中找出预先设定的含N、S化合物。且此语言可以通过后续不断补充完善,实现对焦油中的N、S化合物更加完善地鉴定分析。(The invention provides a method for detecting nitrogen and sulfur compounds in tar by using a full two-dimensional gas chromatograph-mass spectrometer, belonging to the field of tar analysis. The invention realizes the rapid detection of the nitrogen and sulfur compounds in the tar by pre-editing the computer language. The N-containing compounds in the tar mainly comprise pyridine, quinoline, indole, carbazole, benzoquinoline, benzocarbazole and alkyl substitutes of various compounds; the S-containing compound mainly comprises thiophene, benzothiophene, dibenzothiophene and alkyl substituent of each type of compound, and isomers of the same type of compound have the same or similar mass spectrum data, a computer language is pre-edited according to the mass spectrum data of different N, S-containing compounds by a classification method to describe the mass spectrum characteristics of the compounds, and then the preset N, S-containing compound is found out in a full two-dimensional chromatogram by using the language. And the language can be continuously supplemented and improved subsequently, so that N, S compounds in the tar can be identified and analyzed more perfectly.)

1. A method for detecting nitrogen and sulfur compounds in tar by using a full two-dimensional gas chromatograph-mass spectrometer is characterized by comprising the following steps:

mixing tar with an organic solvent and drying to obtain a pretreatment solution;

sequentially filtering, washing filter residues, concentrating and fixing the volume of the pretreatment solution to obtain a solution to be detected;

carrying out full two-dimensional gas chromatography-mass spectrometry detection on the liquid to be detected to obtain total ion current data of a sample;

analyzing the total ion flow data of the sample by using a full two-dimensional data analysis software GC Image through a pre-edited computer language, and rapidly detecting nitrogen and sulfur compounds in the coal tar;

the pre-editing computer language is as follows: the computer expression language is obtained according to the arrangement sequence of the mass-nuclear ratio of nitrogen and sulfur compounds in tar in a mass spectrogram by using two functions ORDINAL and INTENSITY and two operators "&", "|" in the GC Image.

2. The method of claim 1, wherein said nitrogen-containing compounds in said tar comprise pyridine, quinoline, indole, carbazole, benzoquinoline, benzocarbazole, and alkyl substituents of each type of compound.

3. The method of claim 1 or 2, wherein said computer-expressed language of nitrogen-containing compounds in tar is: (ORDINAL (79) & (1) & (ORDINAL (52) &2)) ((ORDINAL (93) &1) & (ORDINAL (66) &2)) | (ORDINAL (107) &1) & (ORDINAL (66) &2)) | ((ORDINAL (121) &1) ((ORDINAL (79) &2))) | (ORDINAL (129) &1) | (ORDINAL (143) ═ 1) | (ORDINAL (144) | (ORDINAL (157) | (ORDINAL (1) | (ORDINAL (170) | (ornal (170) ═ 1) | (ORDINAL (171) &) | ((ornal) (156) & (1) & (INTENSITY)) >0) | ((ORDINAL) (ornal) (351) | (84) & (90) | (ornal) &0) ((ornal) | (ornal) (144) & (1) | (195) | (ornal) (1) | (195) & (195) } 1) | (ornal) (1) | (195) | (1) } 1) | (195) } 1) ((ornal) (167) } 1) |)))))))))))))))) (195) (( (INTENSITY (180) > 0)).

4. The method of claim 1, wherein said sulfur-containing compounds in said tar comprise thiophene, benzothiophene, dibenzothiophene, and alkyl substituents of each type of compound.

5. The method according to claim 1 or 4, wherein the computer-expressed language of the sulfur-containing compounds in the tar is (ORDINAL (84) ═ 1) | (ORDINAL (97) ═ 1) | (ORDINAL (147) ═ 1) | (ORDINAL (184) ═ 1) | (ORDINAL (198) ═ 1).

6. The method of claim 1, wherein the GC-GC conditions for the full-two-dimensional GC-MS detection are as follows: a chromatographic column: first dimension, DB-1, 15m 0.25mm 0.25 μm, second dimension, BPX-50, 2.75m 0.1mm 0.1 μm; the sample injection amount is 1 mu L, the split ratio is 10:1, the temperature of a sample injection port is 300 ℃, the carrier gas is high-purity He, the purity is 99.999 percent, and the constant flow rate is 1 mL/min; temperature program of chromatographic column: initial temperature 60 ℃, ramp to 300 ℃ at 3 ℃/min, modulator temperature: the initial temperature is 150 ℃, the temperature is increased to 300 ℃ at the speed of 5 ℃/min until the detection is finished, and the modulation period is 6 s.

7. The method of claim 1, wherein the MS conditions for the full two-dimensional GC-MS assay are: delaying the solvent for 6 min; EI ionization source, wherein the ion source temperature is 230 ℃, and the bombardment voltage is 70 eV; the temperature of the transmission line is 300 ℃, the scanning nucleus ratio range is 45-500 amu, and the scanning frequency is 50 Hz.

8. The method of claim 1, wherein the organic solvent is methylene chloride.

9. The method of claim 1, wherein the drying uses anhydrous sodium sulfate.

10. A method according to claim 1, wherein the filtration uses a filter cloth with a pore size of 0.075 mm.

Technical Field

The invention relates to the technical field of tar analysis, in particular to a method for detecting nitrogen and sulfur compounds in tar by using a full-two-dimensional gas chromatograph-mass spectrometer.

Background

Coal tar is a liquid product obtained in the processes of carbonization and gasification of coal, and can be roughly divided into the following components according to different carbonization temperatures: low temperature coal tar (450-550 ℃), medium temperature coal tar (600-800 ℃) and high temperature coal tar (1000 ℃). The species in coal tar can be as many as ten thousands, and the compounds which are currently characterized are mainly aromatic hydrocarbon compounds with 1-8 rings and a small amount of polycyclic compounds containing nitrogen, sulfur and oxygen heteroatoms.

Although the content of N, S heteroatom compounds in the coal tar is relatively low (1.5-2 wt%), the existence of the N, S heteroatom compounds has great influence on the properties and subsequent utilization of the coal tar. By using coal tar containing N, S compound as fuel, NO may be generated_xAnd SO_xThe air pollution is caused by the emission of the waste water. In addition, the presence of these N, S compounds can lead to corrosion of equipment during subsequent coal tar hydro-utilization and even cause catalyst poisoning deactivation. Therefore, the deep knowledge of the form distribution of the heteroatoms such as N, S in the coal tar has important guiding significance for improving the utilization value, improving the upgrading process and protecting the environment.

GC-MS combines the high-efficiency separation performance of gas chromatography with the powerful qualitative function of mass spectrometry, and has been widely used in coal liquefaction, pyrolysis, and composition analysis of extracted products. In a two-dimensional gas chromatography-mass spectrometry (GC x GC-MS) developed in recent years, two sets of chromatographic columns with different polarities are connected in series, orthogonal separation of complex samples is realized under the action of a modulator, co-flow substances which cannot be separated on a one-dimensional chromatographic column can be separated again on the two-dimensional chromatographic column according to the polarity difference among components, the detected peak capacity is greatly improved, the separation degree is improved, and therefore the requirements of analyzing various trace and complex organic matters in the samples are met on the premise of minimum sample preparation and highest analysis flux. In the prior art, a method for identifying a compound by using GC-MS is mainly characterized in that a computer is used for searching and comparing a mass spectrogram of a standard compound, and the structure of the compound is determined according to confidence coefficient or similarity. However, GC × GC has a very strong resolving power, and the detection limit is greatly reduced due to the full two-dimensional modulation function, so that a large amount of mass spectrum data is generated by using full two-dimensional analysis, which is about 25 times that of the conventional one-dimensional GC, and it is a heavy work task to manually perform one-to-one matching analysis of mass spectrum libraries on each chromatographic peak in a complex sample. In addition, the structure of the N, S heteroatom-containing compound in the tar is complex, the number of isomers is large, and the content is low, so that the N, S heteroatom-containing compound is distributed and dispersed in a full two-dimensional spectrogram, the peak intensity is low, and the searching is difficult.

Disclosure of Invention

In view of the above, the present invention provides a method for detecting nitrogen and sulfur compounds in tar by using a two-dimensional GC-MS. The method provided by the invention realizes the rapid detection of the nitrogen and sulfur compounds in the tar by pre-editing the computer language.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a method for detecting nitrogen and sulfur compounds in tar by using a full two-dimensional gas chromatograph-mass spectrometer, which comprises the following steps:

mixing tar with an organic solvent and drying to obtain a pretreatment solution;

sequentially filtering, washing filter residues, concentrating and fixing the volume of the pretreatment solution to obtain a solution to be detected;

carrying out full two-dimensional gas chromatography-mass spectrometry detection on the liquid to be detected to obtain total ion current data of a sample;

analyzing the total ion flow data of the sample by using a fully two-dimensional data analysis software GCImage through a pre-edited computer language, and rapidly detecting nitrogen and sulfur compounds in the coal tar;

the pre-editing computer language is as follows: the computer expression language is obtained by utilizing two functions ORDINAL and INTENSITY and two operators "&", "|" in the GCimage according to the arrangement sequence of the mass-nucleus ratios of nitrogen and sulfur compounds in tar in a mass spectrogram.

Preferably, the nitrogen-containing compounds in the tar comprise pyridine, quinoline, indole, carbazole, benzoquinoline, benzocarbazole and alkyl substituents of various types of compounds.

Preferably, the computer-expressed language of the nitrogen-containing compounds in the tar is: (ORDINAL (79) & (1) & (ORDINAL (52) &2)) ((ORDINAL (93) &1) & (ORDINAL (66) &2)) | (ORDINAL (107) &1) & (ORDINAL (66) &2)) | ((ORDINAL (121) &1) ((ORDINAL (79) &2))) | (ORDINAL (129) &1) | (ORDINAL (143) ═ 1) | (ORDINAL (144) | (ORDINAL (157) | (ORDINAL (1) | (ORDINAL (170) | (ornal (170) ═ 1) | (ORDINAL (171) &) | ((ornal) (156) & (1) & (INTENSITY)) >0) | ((ORDINAL) (ornal) (351) | (84) & (90) | (ornal) &0) ((ornal) | (ornal) (144) & (1) | (195) | (ornal) (1) | (195) & (195) } 1) | (ornal) (1) | (195) | (1) } 1) | (195) } 1) ((ornal) (167) } 1) |)))))))))))))))) (195) (( (INTENSITY (180) > 0)).

Preferably, the sulfur-containing compounds in the tar include thiophene, benzothiophene, dibenzothiophene, and alkyl substituents of each type of compound.

Preferably, the computer-expressed language of the sulfur-containing compounds in the tar is (ORDINAL (84) ═ 1) | (ORDINAL (97) ═ 1) | (ORDINAL (147) ═ 1) | (ORDINAL (184) ═ 1) | (ORDINAL (198) ═ 1).

Preferably, the GC × GC conditions of the full-two-dimensional gas chromatography-mass spectrometry detection are as follows: a chromatographic column: first dimension, DB-1, 15m 0.25mm 0.25 μm, second dimension, BPX-50, 2.75m 0.1mm 0.1 μm; the sample injection amount is 1 mu L, the split ratio is 10:1, the temperature of a sample injection port is 300 ℃, the carrier gas is high-purity He, the purity is 99.999 percent, and the constant flow rate is 1 mL/min; temperature program of chromatographic column: initial temperature 60 ℃, ramp to 300 ℃ at 3 ℃/min, modulator temperature: the initial temperature is 150 ℃, the temperature is increased to 300 ℃ at the speed of 5 ℃/min until the detection is finished, and the modulation period is 6 s.

Preferably, the MS conditions for the full two-dimensional gas chromatography-mass spectrometry detection are: delaying the solvent for 6 min; EI ionization source, wherein the ion source temperature is 230 ℃, and the bombardment voltage is 70 eV; the temperature of the transmission line is 300 ℃, the scanning nucleus ratio range is 45-500 amu, and the scanning frequency is 50 Hz.

Preferably, the organic solvent is dichloromethane.

Preferably, the drying uses anhydrous sodium sulfate.

Preferably, the filtration uses a filter cloth with a pore size of 0.075 mm.

The invention provides a method for detecting nitrogen and sulfur compounds in tar by using a full two-dimensional gas chromatograph-mass spectrometer, which comprises the following steps: mixing tar with an organic solvent and drying to obtain a pretreatment solution; sequentially filtering, washing filter residues, concentrating and fixing the volume of the pretreatment solution to obtain a solution to be detected; carrying out full two-dimensional gas chromatography-mass spectrometry detection on the liquid to be detected to obtain total ion current data of a sample; analyzing the total ion flow data of the sample by using a fully two-dimensional data analysis software GCImage through a pre-edited computer language, and rapidly detecting nitrogen and sulfur compounds in the coal tar; the pre-editing computer language is as follows: the computer expression language is obtained by utilizing two functions ORDINAL and INTENSITY and two operators "&", "|" in the GCimage according to the arrangement sequence of the mass-nucleus ratios of nitrogen and sulfur compounds in tar in a mass spectrogram. The method is scientific and reasonable, is simple and convenient to operate, and meanwhile, the pre-edited computer language can be completed through follow-up continuous supplement, so that the nitrogen and sulfur compounds in the tar can be identified and analyzed more perfectly. According to the invention, by combining the research of a person before analysis, the S-containing compound in the tar mainly comprises thiophene, benzothiophene, dibenzothiophene and alkyl substitutes of various compounds; the N-containing compound mainly comprises pyridine, quinoline, indole, carbazole, benzoquinoline, benzocarbazole and alkyl substituent of various compounds. Because isomers of the same type of compound have the same or similar mass spectrum data, a computer language can be pre-edited according to mass spectrum data of different N, S-containing compounds by a classification method, and then a preset N, S-containing compound can be found in a full two-dimensional chromatogram by using the language.

Drawings

FIG. 1 is a graph showing the results of detection of N, S-containing compound in sample A according to the present invention;

FIG. 2 is a graph showing the results of detection of N, S-containing compound in sample B of the present invention.

Detailed Description

The invention provides a method for detecting nitrogen and sulfur compounds in tar by using a full two-dimensional gas chromatograph-mass spectrometer, which comprises the following steps:

mixing tar with an organic solvent and drying to obtain a pretreatment solution;

sequentially filtering, washing filter residues, concentrating and fixing the volume of the pretreatment solution to obtain a solution to be detected;

carrying out full two-dimensional gas chromatography-mass spectrometry detection on the liquid to be detected to obtain total ion current data of a sample;

analyzing the total ion flow data of the sample by using a fully two-dimensional data analysis software GCImage through a pre-edited computer language, and rapidly detecting nitrogen and sulfur compounds in the coal tar;

the pre-editing computer language is as follows: the computer expression language is obtained by utilizing two functions ORDINAL and INTENSITY and two operators "&", "|" in the GCimage according to the arrangement sequence of the mass-nucleus ratios of nitrogen and sulfur compounds in tar in a mass spectrogram.

In the present invention, the nitrogen-containing compound in the tar preferably includes pyridine, quinoline, indole, carbazole, benzoquinoline, benzocarbazole and alkyl substituents of each type of compound.

In the present invention, the sulfur-containing compounds in the tar preferably include thiophene, benzothiophene, dibenzothiophene, and alkyl substituents of each type of compound.

The invention mixes tar and organic solvent and dries them to obtain pretreatment liquid. In the present invention, the organic solvent is preferably dichloromethane. The source of the tar in the present invention is not particularly limited, and any source known to those skilled in the art may be used. In the present invention, the amount ratio of the tar to the organic solvent is preferably 1 g: 25 mL.

In the present invention, the drying is preferably performed using anhydrous sodium sulfate. In the present invention, the mass ratio of the tar to the anhydrous sodium sulfate is preferably 1: 5.

after the pretreatment liquid is obtained, the pretreatment liquid is sequentially filtered, residue is washed, concentrated and subjected to constant volume to obtain the liquid to be detected. In the present invention, the filtration preferably uses a filter cloth having a pore size of 0.075 mm.

In the present invention, CH is preferably used₂Cl₂Washing the filter residue.

In the present invention, the filtrate is preferably concentrated by a rotary evaporator, and the volume is adjusted to 10mL, and finally the filtrate is transferred to a sample bottle to preserve the solution to be tested.

After the liquid to be detected is obtained, the invention carries out full two-dimensional gas chromatography-mass spectrometry detection on the liquid to be detected to obtain the total ion flow data of the sample.

In the present invention, the GC × GC conditions of the full two-dimensional gas chromatography-mass spectrometry detection are preferably: a chromatographic column: first dimension, DB-1, 15m 0.25mm 0.25 μm, second dimension, BPX-50, 2.75m 0.1mm 0.1 μm; the sample injection amount is 1 mu L, the split ratio is 10:1, the temperature of a sample injection port is 300 ℃, the carrier gas is high-purity He, the purity is 99.999 percent, and the constant flow rate is 1 mL/min; temperature program of chromatographic column: initial temperature 60 ℃, ramp to 300 ℃ at 3 ℃/min, modulator temperature: the initial temperature is 150 ℃, the temperature is increased to 300 ℃ at the speed of 5 ℃/min until the detection is finished, and the modulation period is 6 s.

In the present invention, the MS conditions for the comprehensive two-dimensional gas chromatography-mass spectrometry detection are preferably: delaying the solvent for 6 min; EI ionization source, wherein the ion source temperature is 230 ℃, and the bombardment voltage is 70 eV; the temperature of the transmission line is 300 ℃, the scanning nucleus ratio range is 45-500 amu, and the scanning frequency is 50 Hz.

After obtaining total ion flow data of a sample, analyzing the total ion flow data of the sample by using full two-dimensional data analysis software GCImage through a pre-editing computer language, and rapidly detecting nitrogen and sulfur compounds in coal tar; the pre-editing computer language is as follows: the computer expression language is obtained according to the arrangement sequence of the mass-nuclear ratio of nitrogen and sulfur compounds in tar in a mass spectrogram by using two functions ORDINAL and INTENSITY and two operators "&", "|" in the GC Image.

In the present invention, the analyzing of the total ion flow data of the sample preferably comprises the steps of: 1. performing baseline calibration on tar data; 2. setting the signal-to-noise ratio of data to be acquired, and determining the positions of all substances contained in the sample in the total ion current chromatogram; 3. and comparing the mass spectrum data of the substance with the determined position with a NIST standard database to identify the structure of the substance.

In the present invention, the N, S-containing compound in the tar generally includes pyridine, quinoline, indole, carbazole, benzoquinoline, benzocarbazole, thiophene, benzothiophene, dibenzothiophene and alkyl substituents of various types of compounds, and from mass spectra of these substances, the mass spectra of isomer substances have the same or similar characteristic ion peaks, or the distribution of ion peaks has a certain rule. Therefore, the mass spectrum information of the substances can be preset and then returned to the total ion current data of all the substances in the tar, so that the substances with the set mass spectrum information can be searched directionally.

In the present invention, the ORDINAL represents the arrangement order of a certain mass-to-nuclear ratio in a mass spectrogram, such as ORDINAL (79) ═ 1, which means that the peak with the mass-to-nuclear ratio of 79 is the highest peak in the mass spectrogram; INTENSITY represents the abundance of a certain mass-to-nuclear ratio in a mass spectrum, such as INTENSITY (91) >0, expressed in the meaning of a mass spectrum containing a peak with a mass-to-nuclear ratio of 91; the relation of "&" for "and"; "|" represents the relationship of "or".

In the present invention, the computer expression language is preferably as shown in table 1.

TABLE 1 computer expression language for nitrogen and sulfur compounds

In order to further illustrate the present invention, the method for detecting nitrogen and sulfur compounds in tar by using the full two-dimensional GC-MS provided in the present invention is described in detail with reference to the following examples, which should not be construed as limiting the scope of the present invention.