阅读说明：本技术 一种检测四氯化钛中有机物的方法 (Method for detecting organic matters in titanium tetrachloride ) 是由 孙姝琦 殷杰 杨宇斐 刘静 崔爽 于 2019-08-20 设计创作，主要内容包括：本发明公开了一种检测四氯化钛中有机物的方法,首先绘制烷烃、苯系物、氧化物和氯化物的标准曲线；随后对空白样品和待测四氯化钛样品进行水解反应,水解反应后的样品进行顶空-气相色谱质谱联用法检测,得到待测四氯化钛样品总离子流色谱图,最终通过绘制的标准曲线和待测四氯化钛样品总离子流色谱图来确定待测四氯化钛样品中有机物的种类和含量。该方法具有简便、快速、绿色环保、准确、灵敏度高的特点。(The invention discloses a method for detecting organic matters in titanium tetrachloride, which comprises the following steps of firstly, drawing a standard curve of alkane, benzene series, oxide and chloride; and then, carrying out hydrolysis reaction on the blank sample and the titanium tetrachloride sample to be detected, carrying out headspace-gas chromatography-mass spectrometry combined detection on the sample after the hydrolysis reaction to obtain a total ion current chromatogram of the titanium tetrachloride sample to be detected, and finally determining the type and the content of the organic matters in the titanium tetrachloride sample to be detected through a drawn standard curve and the total ion current chromatogram of the titanium tetrachloride sample to be detected. The method has the characteristics of simplicity, convenience, rapidness, environmental protection, accuracy and high sensitivity.)

1. A method for detecting organics in titanium tetrachloride comprising:

step S1: preparing a series of working curve solutions containing alkane, benzene series, oxide and chloride;

step S2: performing headspace-gas chromatography-mass spectrometry combined detection by taking the series of working curve solutions as standard curve samples in the step S1 to obtain a standard curve sample total ion current chromatogram;

step S3: drawing a standard curve of alkane, benzene series, oxide and chloride according to the standard curve solution prepared in the step S1 and the total ion current chromatogram of the standard curve sample in the step S2;

step S4: carrying out hydrolysis reaction on titanium tetrachloride with the purity of more than 99.0%, preferably more than 99.9%, and detecting a sample after the hydrolysis reaction as a blank sample by using a headspace-gas chromatography-mass spectrometry combined method to obtain a blank sample total ion current chromatogram;

step S5: carrying out hydrolysis reaction on a titanium tetrachloride sample to be detected, and detecting the sample after the hydrolysis reaction by using a headspace-gas chromatography-mass spectrometry combined method to obtain a total ion current chromatogram of the titanium tetrachloride sample to be detected;

step S6: and determining the type and the content of the organic matters in the titanium tetrachloride sample to be detected according to the standard curve obtained in the step S3, the blank sample total ion current chromatogram obtained in the step S4 and the titanium tetrachloride sample total ion current chromatogram obtained in the step S5.

2. The method according to claim 1, further comprising step S7: and (4) adding titanium tetrachloride with the purity of more than 99.0 percent, preferably more than 99.9 percent into the series of working curve solution in the step (S1) to perform hydrolysis reaction, and performing headspace-gas chromatography-mass spectrometry combined detection on a sample after the hydrolysis reaction as a standard sample to obtain a total ion current chromatogram of the standard sample.

3. The method according to claim 1 or 2, wherein in step S1, the working curve series solution is formulated using representative substances of said alkanes, benzene series, oxides and chlorides, respectively, preferably said representative substances of alkanes comprise at least one selected from alkanes of C4-C20, said representative substances of benzene series comprise at least one selected from benzenes of C6-C20, said representative substances of oxides comprise at least one selected from alcohols of C1-C12, ketones of C3-C12, ethers of C4-C12 and esters of C2-C12, said representative substances of chlorides comprise chlorides selected from C1-C12, more preferably hexane, toluene, methanol, 1, 2-dichloroethane are used as representative substances of said alkanes, benzene series, oxides and chlorides, respectively.

4. A process according to any one of claims 1 to 3, wherein the hydrolysis reaction is carried out by: adding 5-10mL, preferably 4.5-5.5mL of ultrapure water or deionized water into a 20mL headspace bottle, dropwise adding 0.1-1mL, preferably 0.4-0.6mL of titanium tetrachloride sample, and carrying out hydrolysis reaction;

and/or the temperature of the hydrolysis reaction is 15-35 ℃, preferably 20-25 ℃; the time of the hydrolysis reaction is 5-30min, preferably 8-15 min.

5. The method according to any one of claims 1-4, wherein the conditions of the headspace are: heating the headspace at 80-95 deg.C, the temperature of the transmission line at 80-120 deg.C, the temperature of the headspace sampling needle at 80-130 deg.C, and heating time for 5-60 min; preferably, the headspace is heated to 85-95 ℃, the temperature of the transmission line is 90-110 ℃, the temperature of the headspace sampling needle is 100-; more preferably, the headspace is heated to 90 ℃, the temperature of the transfer line is 100 ℃, the temperature of the headspace sampling needle is 110 ℃, and the heating time is 30 min.

6. The method according to any one of claims 1 to 5, wherein the gas chromatography conditions are: the temperature of the sample inlet is 200-;

preferably, the temperature of the sample inlet is 200-;

more preferably, the injection port temperature is 200 ℃, the injection port type is a split injection port, the split ratio of the injection port is 50:1, the flow rate of the carrier gas is 1.0mL/min, the chromatographic column is an HP-5MS chromatographic column, the temperature rise method is to maintain 35 ℃ for 3min, raise the temperature by 10 ℃/min to 250 ℃ for 5min, and the temperature of the chromatographic mass spectrometry connecting rod is 200 ℃.

7. The method of any one of claims 1-6, wherein the conditions of mass spectrometry are: the mass spectrum ion source is an electron bombardment ionization source, the mass spectrum collection type is full scanning m/z 20-500, and the temperature of the mass spectrum ion source is 200-280 ℃, preferably 220-240 ℃, and more preferably 230 ℃.

8. The method according to any one of claims 1 to 7, wherein in step S4, a standard curve of hydrocarbons, benzenes, oxides, chlorides is plotted with mass as X-axis and total ion current chromatogram integrated peak area as Y-axis, preferably the standard curve has a linear range of 0.01 to 1mg/mL and a linear correlation coefficient > 0.99.

9. The method according to any one of claims 1 to 8, characterized in that, the method comprises the steps of integrating the chromatographic peaks in the total ion current chromatogram of the titanium tetrachloride sample to be detected, carrying out qualitative analysis by NIST library search, and carrying out quantitative analysis by peak area to obtain the types and contents of various organic matters in the titanium tetrachloride; and/or

In the method, the sample recovery rate of the alkane, the benzene series, the oxide and the chloride is more than 60 percent, the relative standard deviation is less than 20 percent, and the detection limit is 0.01 mg/kg.

10. Use of the method according to claims 1-9 for the quality control of titanium tetrachloride impurity detection or recovery of titanium tetrachloride from mixed titanium tetrachloride waste slag streams.

Technical Field

The invention belongs to the field of chemical substance detection, particularly relates to a method for detecting organic matters in titanium tetrachloride, and particularly relates to a method for detecting a plurality of organic matters in titanium tetrachloride by a headspace-gas chromatography-mass spectrometry (HS-GC/MS) combined method.

Background

Titanium tetrachloride is an important intermediate for producing titanium sponge, metallic titanium and titanium dioxide, can also be used for manufacturing alloys, pigments and smoke screen agents for national defense, and is also a good solvent for dissolving polymers such as rubber and plastics. In the polyolefin industry, titanium tetrachloride is one of important active substances in a titanium magnesium system Ziegler-Natta catalyst, and the type and content of impurities of the titanium tetrachloride can greatly influence the effect of the polyolefin catalyst.

The SiCl in the titanium tetrachloride is tested by using inductively coupled plasma atomic emission spectrometry (ICP) in the nonferrous metal industry standard YS/T655-2016 titanium tetrachloride of the people's republic of China₄、FeCl₃、VOCl₃、AlCl₃、SnCl₄However, no method for analyzing organic impurities is specified.

As a method for analyzing organic compounds in titanium tetrachloride, there have been disclosed methods for detecting such compounds as infrared spectroscopy and chromatography, for example:

a publication of Tan Red and other infrared spectroscopic analysis of trace organic impurities in refined titanium tetrachloride is published in analytical test bulletin 2012, and a zinc selenide window and a polytetrafluoroethylene infrared liquid pool are used for detecting organic impurities such as trichloroacetyl chloride and the like in titanium tetrachloride.

In a reference of 'different extracting agent extraction capability comparison' for measuring trace amount of carbon tetrachloride in a titanium tetrachloride hydrolysis system by 'liquid-liquid extraction gas chromatography', which is disclosed in 'metallurgy analysis' of 2014, such as Liqing, organic solvents, such as heptane, normal hexane, normal octane, isooctane and the like are used for liquid-liquid extraction, and gas chromatography is used for quantitative analysis of the carbon tetrachloride in the titanium tetrachloride.

A method for analyzing and detecting impurities containing chlorine compounds by using infrared spectroscopy, ion chromatography and gas chromatography is disclosed in a doctor's academic paper' analysis of main impurities in refined titanium tetrachloride and process control research 'of the main impurities in refined titanium tetrachloride' of Song Guanglin university of Beijing Physician 2015.

In the method for detecting organic impurities in titanium tetrachloride reported in the above documents, a special infrared absorption cell device is required for infrared spectroscopy, the detection of trace impurities is difficult due to low infrared spectral sensitivity, and the gas chromatography requires liquid-liquid extraction and other pretreatment steps and has poor qualitative capability.

In the polyolefin catalyst preparation industry, trace impurities in titanium tetrachloride can reduce the activity of the catalyst, so that the analytical method with simple establishment method, high sensitivity and strong qualitative capability is used for monitoring organic impurities in the refining and recycling of industrial titanium tetrachloride, and has important significance for avoiding environmental pollution and reasonably recycling waste liquid and waste residues in the production and use processes of titanium tetrachloride.

At present, no report on analysis of trace organic matters in titanium tetrachloride by a headspace-gas chromatography-mass spectrometry combined method exists, the method fills the blank, reduces the sample pretreatment steps, has no solvent pollution, and quickly performs qualitative and quantitative analysis on the organic matters in the titanium tetrachloride.

Disclosure of Invention

Aiming at the technical problems, the invention provides a method for detecting organic matters in titanium tetrachloride by using a headspace-gas chromatography-mass spectrometry combined method, which has the characteristics of simplicity, convenience, rapidness, accuracy and high sensitivity.

According to one aspect of the present invention, there is provided a method for detecting an organic compound in titanium tetrachloride, comprising:

step S1: preparing a series of working curve solutions containing alkane, benzene series, oxide and chloride;

step S2: performing headspace-gas chromatography-mass spectrometry combined detection by taking the series of working curve solutions as standard curve samples in the step S1 to obtain a standard curve sample total ion current chromatogram;

step S3: drawing a standard curve of alkane, benzene series, oxide and chloride according to the standard curve solution prepared in the step S1 and the total ion current chromatogram of the standard curve sample in the step S2;

step S4: carrying out hydrolysis reaction on titanium tetrachloride with the purity of more than 99.0%, preferably more than 99.9%, and detecting a sample after the hydrolysis reaction as a blank sample by using a headspace-gas chromatography-mass spectrometry combined method to obtain a blank sample total ion current chromatogram;

step S5: carrying out hydrolysis reaction on a titanium tetrachloride sample to be detected, and detecting the sample after the hydrolysis reaction by using a headspace-gas chromatography-mass spectrometry combined method to obtain a total ion current chromatogram of the titanium tetrachloride sample to be detected;

step S6: and determining the type and the content of the organic matters in the titanium tetrachloride sample to be detected according to the standard curve obtained in the step S3, the blank sample total ion current chromatogram obtained in the step S4 and the titanium tetrachloride sample total ion current chromatogram obtained in the step S5.

According to some embodiments of the invention, the method further comprises step S7: and (4) adding titanium tetrachloride with the purity of more than 99.0 percent, preferably more than 99.9 percent into the series of working curve solution in the step (S1) to perform hydrolysis reaction, and performing headspace-gas chromatography-mass spectrometry combined detection on a sample after the hydrolysis reaction as a standard sample to obtain a total ion current chromatogram of the standard sample.

According to some embodiments of the invention, in step S1, a series of working curve solutions are formulated using representative species of the alkanes, benzenes, oxides, and chlorides, respectively.

According to a preferred embodiment of the present invention, in step S1, the representative substance of alkane includes at least one selected from alkanes of C4-C20, the representative substance of benzene series includes at least one selected from benzene series of C6-C20, the representative substance of oxide includes at least one selected from alcohols of C1-C12, ketones of C3-C12, ethers of C4-C12 and esters of C2-C12, and the representative substance of chloride includes chloride selected from chlorides of C1-C12.

According to a preferred embodiment of the present invention, in step S1, a series of working curve solutions were prepared using hexane, toluene, methanol, 1, 2-dichloroethane as representative substances of the alkane, the benzene series, the oxide, and the chloride, respectively.

According to a preferred embodiment of the present invention, in step S1, a series of working curve solutions is formulated using ethanol as a representative substance of the oxide.

According to a preferred embodiment of the present invention, in step S1, a series of working curve solutions were formulated using 1, 2-dichloroethane as a representative of the chloride.

According to a preferred embodiment of the present invention, the method of preparing the standard solution is as follows: respectively weighing about 0.25g of hexane, toluene, methanol and 1, 2-dichloroethane in a 25mL volumetric flask, adding isopropanol to a constant volume until the volume is regulated to a scribed line, preparing a series of working curve solution mother liquor with the concentration of each substance of hexane, toluene, methanol and 1, 2-dichloroethane of 10mg/mL, and storing in a refrigerator at 4 ℃. The standard mother liquor has a shelf life of 1 month, and needs to be reconfigured when the standard mother liquor is expired. The mother liquor of the standard solution is diluted to 0.01-1mg/mL standard solution with isopropanol.

According to the preferred embodiment of the present invention, the mother liquor of the standard solution is diluted stepwise with isopropanol to 0.01, 0.1, 0.2, 0.5, 1mg/mL of the standard solution.

According to some embodiments of the invention, the method of the hydrolysis reaction is: and (3) taking a 20mL headspace bottle, adding 5-10mL ultrapure water or deionized water, and dropwise adding 0.1-1mL titanium tetrachloride for hydrolysis reaction. And after the hydrolysis reaction is finished, sealing the opening of the jaw by using an aluminum cover to be detected.

According to a preferred embodiment of the present invention, the hydrolysis reaction is carried out by: and (3) taking a 20mL headspace bottle, adding 4.5-5.5mL ultrapure water or deionized water, and dropwise adding 0.4-0.6mL titanium tetrachloride for hydrolysis reaction. And after the hydrolysis reaction is finished, sealing the opening of the jaw by using an aluminum cover to be detected.

According to a preferred embodiment of the present invention, the hydrolysis reaction is carried out by: a20 mL headspace bottle was charged with 5mL ultrapure water or deionized water, and 0.5mL titanium tetrachloride was added dropwise for hydrolysis. And after the hydrolysis reaction is finished, sealing the opening of the jaw by using an aluminum cover to be detected.

According to some embodiments of the invention, the temperature of the hydrolysis reaction is 15 to 35 ℃ and the time of the hydrolysis reaction is 5 to 30 min.

According to a preferred embodiment of the invention, the temperature of the hydrolysis reaction is 20-25 ℃; the time of the hydrolysis reaction is 8-15 min.

According to some embodiments of the invention, the standard curve sample is prepared as follows: and (3) taking a 20mL headspace bottle, and respectively adding 10-1000 mu L of the series of working curve solutions with different concentrations to perform hydrolysis reaction. After the hydrolysis reaction is finished, the jaw is sealed by an aluminum cover, and the jaw is used as a standard solution to be added with a sample to be detected.

According to a preferred embodiment of the present invention, the standard curve sample is prepared as follows: and (3) taking a 20mL headspace bottle, and respectively adding 50-150 mu L of the series of working curve solutions with different concentrations to perform hydrolysis reaction. After the hydrolysis reaction is finished, the jaw is sealed by an aluminum cover, and the jaw is used as a standard solution to be added with a sample to be detected.

According to a preferred embodiment of the present invention, the standard curve sample is prepared as follows: and (3) taking a 20mL headspace bottle, and respectively adding 100 mu L of the series of working curve solutions with different concentrations for hydrolysis reaction. After the hydrolysis reaction is finished, the jaw is sealed by an aluminum cover, and the jaw is used as a standard solution to be added with a sample to be detected.

According to some embodiments of the invention, the blank sample is prepared as follows: titanium tetrachloride (analytically pure or otherwise of the same purity) of greater than 99.0%, preferably greater than 99.9%, is used as a blank sample reagent. And (3) taking a 20mL headspace bottle, adding 5-10mL ultrapure water or deionized water, and slowly dropwise adding 0.1-1mL titanium tetrachloride for hydrolysis reaction. And after the hydrolysis reaction is finished, sealing the opening of the jaw by using an aluminum cover, and taking the opening as a blank sample to be detected.

According to some embodiments of the invention, the blank sample is prepared as follows: titanium tetrachloride (analytically pure or otherwise of the same purity) of greater than 99.0%, preferably greater than 99.9%, is used as a blank sample reagent. A20 mL headspace bottle was charged with 5mL ultrapure water or deionized water, and 0.5mL titanium tetrachloride was slowly added dropwise for hydrolysis. And after the hydrolysis reaction is finished, sealing the opening of the jaw by using an aluminum cover, and taking the opening as a blank sample to be detected.

According to some embodiments of the invention, the preparation of the spiked sample is as follows: and (3) taking a 20mL headspace bottle, respectively adding 10-1000 μ L of the series of working curve solutions with different concentrations, adding 5-10mL of ultrapure water or deionized water, slowly dropwise adding 0.1-1mL of titanium tetrachloride (analytically pure or other same purity) with the purity of more than 99.0%, preferably more than 99.9%, and carrying out hydrolysis reaction. And after the hydrolysis reaction is finished, sealing the jaw by using an aluminum cover, and taking the jaw as a labeled sample to be detected.

According to some embodiments of the invention, the preparation of the spiked sample is as follows: taking a 20mL headspace bottle, respectively adding 50-150 μ L of the series of working curve solutions with different concentrations, adding 5-10mL of ultrapure water or deionized water, slowly dropwise adding 0.1-1mL of titanium tetrachloride (analytically pure or other same purity) with the purity of more than 99.0%, preferably more than 99.9%, to perform hydrolysis reaction. And after the hydrolysis reaction is finished, sealing the jaw by using an aluminum cover, and taking the jaw as a labeled sample to be detected.

According to a preferred embodiment of the invention, the preparation of the spiked sample is as follows: a20 mL headspace bottle was taken, 100. mu.L of each of the above series of working curve solutions with different concentrations was added, 5mL of ultrapure water was added, and 0.5mL of titanium tetrachloride (analytically pure or otherwise of the same purity) with a purity of more than 99.0%, preferably more than 99.9% was slowly added dropwise to conduct hydrolysis reaction. And after the hydrolysis reaction is finished, sealing the jaw by using an aluminum cover, and taking the jaw as a labeled sample to be detected.

According to some embodiments of the invention, the conditions of the headspace are: heating the headspace at 80-95 deg.C, the temperature of the transmission line at 80-120 deg.C, the temperature of the headspace sampling needle at 80-130 deg.C, and heating time for 5-60 min.

According to a preferred embodiment of the invention, the conditions of the headspace are: heating the headspace at 85-95 deg.C, the temperature of the transmission line at 90-110 deg.C, the temperature of the headspace sampling needle at 100-120 deg.C, and the heating time at 20-40 min.

According to a preferred embodiment of the invention, the conditions of the headspace are: the headspace is heated to 90 ℃, the temperature of the transmission line is 100 ℃, the temperature of the headspace sampling needle is 110 ℃, and the heating time is 30 min.

According to some embodiments of the invention, the gas chromatography conditions are: the sample inlet temperature is 200-280 ℃, the type of the sample inlet is a shunt sample inlet or a shunt/non-shunt sample inlet, the shunt ratio of the sample inlet is 10:1-50:1, the carrier gas is high-purity helium, the flow rate of the carrier gas is 0.5-1.2mL/min, the temperature rise method is that the temperature is programmed to 280 ℃ at 35 ℃, and the temperature of the chromatographic mass spectrum connecting rod is 200-280 ℃.

According to a preferred embodiment of the invention, the gas chromatography conditions are: the temperature of the sample inlet is 200-.

According to a preferred embodiment of the invention, the gas chromatography conditions are: the sample inlet temperature is 200 ℃, the type of the sample inlet is a split sample inlet, the split ratio of the sample inlet is 50:1, the flow rate of the carrier gas is 1.0mL/min, the chromatographic column is an HP-5MS chromatographic column, the temperature rise method is that the temperature is kept for 3min at 35 ℃, is kept for 5min at 250 ℃ at 10 ℃/min, and the temperature of a chromatographic mass spectrum connecting rod is 200 ℃.

According to some embodiments of the invention, the chromatography column used in the gas chromatography comprises any one selected from the group consisting of an HP-5MS column, a medium polarity DB-35MS column, and a polar HP-INNOWAX column.

According to a preferred embodiment of the invention, the chromatography column used for the gas chromatography is an HP-5MS column.

According to some embodiments of the invention, the conditions of the mass spectrum are: the mass spectrum ion source is an electron bombardment ionization source, the temperature of the mass spectrum ion source is 200-280 ℃, and the mass spectrum collection type is full scanning m/z 20-500.

According to a preferred embodiment of the present invention, the mass spectrometry ion source temperature is 220-240 ℃.

According to a preferred embodiment of the invention, the mass spectrometry ion source temperature is 230 ℃.

According to some embodiments of the present invention, the standard curve in step S3 is plotted as follows: and detecting the standard curve samples with different concentrations according to the headspace-gas chromatography-mass spectrometry combined method to obtain a total ion current chromatogram of the standard curve samples. And (3) taking the mass of the added standard curve sample as an X axis, and taking the integrated peak area of the total ion current chromatogram as a Y axis to draw a standard curve of hydrocarbons, benzene series, oxides and chlorides.

According to some embodiments of the invention, the linear range of the standard curve is 0.01-1mg/mL, and the linear correlation coefficient is > 0.99.

According to some embodiments of the invention, a blank sample total ion current chromatogram is shown in fig. 1.

Adding 20mg/kg addition levels of hexane, toluene, methanol and 1, 2-dichloroethane into a titanium tetrachloride blank sample, and detecting the standard samples with different concentrations according to the headspace-gas chromatography-mass spectrometry combined method to obtain a total ion current chromatogram of the standard samples, as shown in fig. 2.

The purpose of the tests carried out on the spiked samples is to verify the feasibility of the process according to the invention, from which the recovery, relative standard deviation RSD and detection limit of alkanes, benzenes, oxides and chlorides in the process according to the invention can be obtained.

According to some embodiments of the invention, the process has a recovery of alkanes, benzenes, oxides and chlorides of > 60%, a relative standard deviation RSD of < 20%, and a detection limit of 0.01 mg/kg.

According to a preferred embodiment of the invention, the recovery of hexane, toluene, methanol, 1, 2-dichloroethane in the process is > 60%, the relative standard deviation RSD is < 20%, and the detection limit is 0.01 mg/kg.

According to the preferred embodiment of the present invention, two addition levels of 20mg/kg and 100mg/kg of hexane, toluene, methanol, 1, 2-dichloroethane were added to a blank sample of titanium tetrachloride, each addition level prepared 6 parallel samples, with sample recoveries of 75-94% and RSD between 5.65-16.14%, and the specific results are shown in table 1.

TABLE 1 recovery with standard and precision test (n ═ 6)

According to some embodiments of the invention, the various spectral peaks in the total ion current chromatogram of the titanium tetrachloride sample to be detected are integrated, qualitative analysis is performed by NIST spectral library retrieval, classification is performed according to hydrocarbons, benzene series, oxides and chlorides, and the types and the contents of various organic matters in the titanium tetrachloride are obtained by using peak areas for quantitative analysis.

According to another aspect of the invention, there is provided the use of a method according to the first aspect for the quality control of titanium tetrachloride impurity detection or recovery of titanium tetrachloride in mixed titanium tetrachloride waste streams.

The invention discloses a method for detecting organic matters in titanium tetrachloride by a headspace-gas chromatography-mass spectrometry combined method. Firstly, ultrapure water or deionized water is added into a headspace bottle, and then titanium tetrachloride is slowly added for hydrolysis reaction. After the hydrolysis reaction is finished, the headspace bottle is sealed and used for analysis by a headspace-gas chromatography-mass spectrometry combined method. Heating by a static headspace method to volatilize the organic matters from the water phase so as to achieve two-phase balance. Headspace gas was injected into the GC-MS for testing. The method is substantially different from the prior art in that the headspace method is green and environment-friendly, reduces the use of extraction solvent, has simple sample pretreatment process, high sensitivity, strong qualitative capability and high accuracy by combining the headspace method and the chromatographic mass spectrometry, and can quickly and accurately detect the organic matters in the titanium tetrachloride.

The method for detecting the organic matters in the titanium tetrachloride is simple and convenient to operate, can be used for detecting titanium tetrachloride impurities and controlling the quality of the mixed titanium tetrachloride waste residue and liquid during the recovery of the titanium tetrachloride, provides technical support for the production, refining, recovery and reutilization of the titanium tetrachloride, improves the economic benefits of enterprises and reduces the environmental pollution.

Drawings

Fig. 1 is a blank sample total ion current chromatogram according to an embodiment of the present invention. The chromatographic peaks are: air for 1.376 min.

FIG. 2 is a total ion flow chromatogram of a spiked sample at a 20mg/kg addition level, according to one embodiment of the invention. The chromatographic peaks are sequentially as follows: 1.386min of air; methanol 1.479min, isopropanol 1.744min, hexane 2.198min, 1, 2-dichloroethane 2.740min, toluene 4.859min, hexane impurity isohexane 2.705min, and methylcyclopentane 2.475 min.

FIG. 3 is a chromatogram of the total ion current of a titanium tetrachloride sample A to be measured in industry in example 1. The chromatographic peaks are sequentially as follows: air 1.389min, toluene 4.859min, ethylbenzene 6.829min, xylene isomer 6.998min, xylene isomer 7.472min, 1, 3-dichloropropene 8.014min methyl ethyl benzene isomer 8.821min, methyl ethyl benzene isomer 8.846min, methyl ethyl benzene isomer 9.162 min.

FIG. 4 is a chromatogram of the total ion current of a titanium tetrachloride sample B to be tested in industrial recovery in example 2. The chromatographic peaks are sequentially as follows: air 1.387min, ethanol 1.577min, isopropanol 1.69min, chloroethylene 2.737min, toluene 4.846min, ethylbenzene 6.831min, xylene 7.0min, 1, 3-dichloropropene 8.014min, methyl ethyl benzene isomer 8.821min, methyl ethyl benzene isomer 8.845min, and methyl ethyl benzene isomer 9.162 min.

In the total ion current chromatogram, an air peak is introduced during sampling, and the peak area does not participate in calculation.

Detailed Description

The technical solution of the present invention is further described below with reference to the accompanying drawings and examples, but the scope of the present invention is not limited to the following embodiments.

Example 1 and example 2 were each tested using the following method:

preparation of standard curve samples: respectively weighing about 0.25g of hexane, toluene, methanol and 1, 2-dichloroethane in a 25mL volumetric flask, adding isopropanol to fix the volume to the scale line, preparing a series of working curve solution mother liquor with the concentration of each substance of hexane, toluene, methanol and 1, 2-dichloroethane of 10mg/mL, and gradually diluting the standard solution mother liquor to 0.01, 0.1, 0.2, 0.5 and 1mg/mL by using isopropanol. And (3) taking a 20mL headspace bottle, respectively adding 100 mu L of standard solutions with different concentrations, sealing by using an aluminum cover with a jaw, and taking the obtained product as a standard curve sample to be detected.

Preparing a blank sample: titanium tetrachloride (analytically pure or of otherwise identical purity, purity > 99.9%) was used as a blank reagent. A20 mL headspace bottle was charged with 5mL ultrapure water, 0.5mL titanium tetrachloride (> 99.9%) was slowly added dropwise, and hydrolysis was carried out at room temperature for 10 min. And after the hydrolysis reaction is finished, sealing the opening of the jaw by using an aluminum cover, and taking the opening as a blank sample to be detected.

Respectively detecting the standard curve sample and the blank sample by adopting the following methods in a headspace-gas chromatography-mass spectrometry combined method:

the instrument comprises the following steps: an Agilent G1888A headspace sampler, and an Agilent 7890A-5975C gas chromatography-mass spectrometer.

Headspace conditions: the headspace is heated to 90 ℃, the temperature of the transmission line is 100 ℃, the temperature of the headspace sampling needle is 110 ℃, and the heating time is 30 min.

Chromatographic conditions are as follows: sample inlet temperature: 200 ℃ and 250 ℃; split-flow sample introduction, split-flow ratio: 50: 1; carrier gas: high purity helium, 1.0 mL/min; HP-5MS column (30 m.times.0.25 mm.times.0.25 μm); the temperature rising method comprises the following steps: keeping the temperature at 35 ℃ for 3min, heating to 250 ℃ at the speed of 10 ℃/min, and keeping the temperature for 5 min; connecting rod temperature: at 200 ℃.

Mass spectrum conditions: electron impact ionization source (EI source), mass spectrometry ion source temperature: 230 ℃; and (3) mass spectrum acquisition type: full scan m/z 20-500.

Drawing a standard curve: the mass (concentration of the solution in the standard curve multiplied by the volume of the solution added) is taken as the X axis, and the integrated peak area of the total ion current chromatogram is taken as the Y axis, so that the standard curve of hexane, toluene, methanol and 1, 2-dichloroethane is drawn and shown in Table 2.

TABLE 2 Standard Curve and Linear correlation coefficient

Species of matter	Representative substances	Linear equation of equations	R2
				Alkane(s)	Hexane (C)	y＝2E+08x+202887	0.9936
Benzene series compound	Toluene	y＝3E+08x+409082	0.9977
				Oxide compound	Methanol	y＝1E+08x+80814	0.9986
Chloride compound	1, 2-dichloroethane	y＝2E+08x+236510	0.9978

The blank sample total ion current chromatogram is shown in FIG. 1.

Example 1

Titanium tetrachloride sample A to be tested: titanium tetrachloride is used in certain polyolefin catalyst production line industry.

Sample pretreatment: a20 mL headspace bottle was taken, 5mL ultrapure water was added, and 0.5mL (0.863g) of a titanium tetrachloride sample to be measured was slowly dropped to the flask for hydrolysis reaction. And after the hydrolysis reaction is finished, sealing the opening by using a jaw aluminum cover.

The instrument comprises the following steps: an Agilent G1888A headspace sampler, and an Agilent 7890A-5975C gas chromatography-mass spectrometer.

Headspace conditions: the headspace is heated to 90 ℃, the temperature of the transmission line is 100 ℃, the temperature of the headspace sampling needle is 110 ℃, and the heating time is 30 min.

Chromatographic conditions are as follows: sample inlet temperature: 200 ℃ and 250 ℃; split-flow sample introduction, split-flow ratio: 50: 1; carrier gas: high purity helium, 1.0 mL/min; HP-5MS column (30 m.times.0.25 mm.times.0.25 μm); the temperature rising method comprises the following steps: keeping the temperature at 35 ℃ for 3min, heating to 250 ℃ at the speed of 10 ℃/min, and keeping the temperature for 5 min; connecting rod temperature: at 200 ℃.

Mass spectrum conditions: electron impact ionization source (EI source), mass spectrometry ion source temperature: 230 ℃; and (3) mass spectrum acquisition type: full scan m/z 20-500.

The chromatogram of the total ion current of the titanium tetrachloride sample A to be detected is shown in figure 3. The sample results of this example were characterized using a NIST library search, and the results are shown in table 3; the results were quantified using an external standard curve and are shown in Table 4.

TABLE 3 area of peak and peak assignment in example 1

Retention time	Peak area	Name of substance
			4.859	237998099	Toluene
6.829	443040	Ethylbenzene production
			6.998	737297	Xylene
7.472	196387	Xylene
			8.014	1719657	1, 3-dichloropropene
8.821	2352228	Methyl ethyl benzene
			8.846	1638044	Methyl ethyl benzene
9.162	798714	Methyl ethyl benzene

Table 4 example 1 calculation results

Species of matter	Sum of Peak areas	Mass (mg)	Content (mg/kg)
				Alkane(s)	——	——	——
Benzene series compound	244163809	0.81	971.91
				Oxide compound	——	——	——
Chloride compound	1719657	0.0074	8.87

Example 2

Titanium tetrachloride sample B to be tested: titanium tetrachloride is industrially recovered in a certain polyolefin catalyst production line.

Sample pretreatment: a20 mL headspace bottle was charged with 5mL ultrapure water, and 0.5mL (0.863g) of titanium tetrachloride was slowly added dropwise to conduct hydrolysis. And after the hydrolysis reaction is finished, sealing the opening by using a jaw aluminum cover.

The instrument comprises the following steps: an Agilent G1888A headspace sampler, and an Agilent 7890A-5975C gas chromatography-mass spectrometer.

Headspace conditions: the headspace is heated to 90 ℃, the temperature of the transmission line is 100 ℃, the temperature of the headspace sampling needle is 110 ℃, and the heating time is 30 min.

Chromatographic conditions are as follows: sample inlet temperature: 200 ℃ and 250 ℃; split-flow sample introduction, split-flow ratio: 50: 1; carrier gas: high purity helium, 1.0 mL/min; HP-5MS column (30 m.times.0.25 mm.times.0.25 μm); the temperature rising method comprises the following steps: keeping the temperature at 35 ℃ for 3min, heating to 250 ℃ at the speed of 10 ℃/min, and keeping the temperature for 5 min; connecting rod temperature: at 200 ℃.

Mass spectrum conditions: electron impact ionization source (EI source), mass spectrometry ion source temperature: 230 ℃; and (3) mass spectrum acquisition type: full scan m/z 20-500.

The chromatogram of the total ion current of the titanium tetrachloride sample B to be detected is shown in figure 4. The sample results of this example were characterized using a NIST library search, and the results are shown in table 5; the results are shown in Table 6, using external standard curve quantification.

TABLE 5 area of peak and peak assignment in example 2

Retention time	Peak area	Name of substance
			1.577	46401	Ethanol
1.69	527205	Isopropanol (I-propanol)
			2.737	31163	Vinyl chloride
4.846	168314287	Toluene
			6.831	329685	Ethylbenzene production
7	523448	Xylene
			8.014	1183969	1, 3-dichloropropene
8.821	1486049	Methyl ethyl benzene
			8.845	968928	Methyl ethyl benzene
9.162	429571	Methyl ethyl benzene

Table 6 example 2 calculation results

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.