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CN-121994939-A - Analysis method for one or more sample components containing 1, 4-cyclohexanedimethanol, 1, 4-cyclohexanedicarboxylic acid dimethyl ester and terephthalic acid dimethyl ester

CN121994939ACN 121994939 ACN121994939 ACN 121994939ACN-121994939-A

Abstract

The invention relates to the technical field of chemical detection, in particular to an analysis method for one or more sample components containing 1, 4-cyclohexanedimethanol, 1, 4-cyclohexanedicarboxylic acid dimethyl ester and terephthalic acid dimethyl ester. The analysis method comprises the steps of sample pretreatment, namely, pretreating a sample to obtain liquid without mechanical impurities as a sample to be detected, and measuring and analyzing the sample to be detected, namely, injecting the sample to be detected into a gas chromatograph for detection, and performing qualitative analysis by using an external standard method, wherein the detection conditions comprise that a detector is FID, and the temperature of the FID detector is 295-320 ℃. The analysis method provided by the invention is simple, good in reproducibility, high in sensitivity, good in stability, simple to operate and high in analysis speed, can meet the analysis requirements of 1, 4-cyclohexanedimethanol and raw materials thereof and hydrogenation products of the raw materials or sample analysis requirements of similar components contained or partially contained, and omits complicated operations of selecting and adding internal standard substances.

Inventors

  • SHI MINGYAN
  • SHI JUN
  • LI ZHENZHONG
  • CHENG GUANGJIAN
  • TIAN ZHENYING
  • HUANG JIYUE
  • SHI HONGBO
  • XU YANQIN
  • WANG LISHU

Assignees

  • 中国石油天然气集团有限公司

Dates

Publication Date
20260508
Application Date
20241101

Claims (16)

  1. 1. A method for analyzing a sample component containing one or more of 1, 4-cyclohexanedimethanol, dimethyl 1, 4-cyclohexanedicarboxylate, and dimethyl terephthalate, the method comprising: Pretreatment of a sample, namely, pretreating the sample to obtain liquid without mechanical impurities as a sample to be detected; The method comprises the steps of determining and analyzing a sample to be detected, namely injecting the sample to be detected into a gas chromatograph for detection, and performing qualitative analysis by using an external standard method; the detection conditions include that the detector is FID and the temperature of the FID detector is 295-320 ℃.
  2. 2. The method of claim 1, wherein the method comprises the steps of, Quantitative determination by area normalization method and/or The detection conditions include: The FID detector temperature is 295-310℃, and/or The temperature of the sample inlet is 250-295 ℃.
  3. 3. The method of claim 1, wherein the detection conditions comprise: The temperature of the column is programmed to rise, namely, after the initial temperature is kept between 105 and 150 ℃ for 1 to 10min, the temperature is raised to between 250 and 295 ℃ at the speed of 5 to 30 ℃ per min and kept for 20 to 50min.
  4. 4. The method of claim 1, wherein the detection conditions comprise: The chromatographic separation column is a capillary chromatographic column, and/or The chromatographic separation column has a length of 15-60m, and/or The inner diameter of the chromatographic separation column is 0.25-0.55mm.
  5. 5. The method of claim 4, wherein the detection conditions comprise: The capillary chromatography column is selected from weak polarity capillary chromatography columns.
  6. 6. The method of claim 5, wherein, The stationary phase on the inner wall of the weak polar capillary chromatographic column is 5wt% phenyl-95 wt% methyl polysiloxane or 5.5wt% phenyl-94.5 wt% dimethyl polysiloxane, and/or The film thickness of the stationary phase on the inner wall of the weak-polarity capillary chromatographic column is 0.25-0.5 mu m.
  7. 7. The method of claim 1, wherein the detection conditions comprise: the split ratio is 60:1-200:1, and/or The carrier gas being nitrogen, and/or The flow rate of the carrier gas is 1-10ml/min, and/or The air flow rate is 200-600ml/min, and/or Hydrogen flow rate of 40-80ml/min, and/or The sample injection amount is 0.2-0.5 mu L.
  8. 8. The method of any one of claims 1 to 7, wherein, When the major component of the sample is 1, 4-cyclohexanedimethanol, the source of the sample includes at least one of the production, use and recovery of 1, 4-cyclohexanedimethanol.
  9. 9. The method of any one of claims 1 to 7, wherein, When the main component of the sample is 1, 4-cyclohexanedimethanol, the sample pretreatment method comprises the steps of heating the sample to 30-100 ℃ for complete melting to obtain the sample to be tested.
  10. 10. The method of any one of claims 1 to 7, wherein, When the main component of the sample is 1, 4-cyclohexanedimethanol, the sample pretreatment method comprises dissolving the sample in a solvent to obtain a sample to be tested, wherein the solvent is selected from monohydric alcohol and/or dihydric alcohol which are liquid at room temperature.
  11. 11. The method of claim 10, wherein the analysis is performed, The solvent is at least one selected from methanol, ethanol and ethylene glycol, and/or In the sample to be detected, the content of the sample is 10-80wt%.
  12. 12. The method of any one of claims 1 to 7, wherein, When the major component of the sample is dimethyl 1, 4-cyclohexanedicarboxylate, the source of the sample includes at least one of the production, use and recovery of dimethyl 1, 4-cyclohexanedicarboxylate.
  13. 13. The method of claim 12, wherein the analysis is performed, When the main component of the sample is dimethyl 1, 4-cyclohexanedicarboxylate, the sample pretreatment method comprises the step of completely melting the sample at 30-100 ℃ to obtain the sample to be tested.
  14. 14. The method of any one of claims 1 to 7, wherein, When the major component of the sample is dimethyl terephthalate, the source of the sample includes at least one of the dimethyl terephthalate production, use and recovery processes.
  15. 15. The method of any one of claims 1 to 7, wherein, When the main component of the sample is dimethyl terephthalate, the sample pretreatment method comprises the step of contacting the sample with a solvent to obtain a sample to be tested, wherein the solvent is selected from dimethyl 1, 4-cyclohexanedicarboxylate and/or ethyl acetate.
  16. 16. The method of claim 15, wherein the method comprises the steps of, The solvent is selected from dimethyl 1, 4-cyclohexanedicarboxylate and/or The temperature of the contact is 60-140℃, and/or The content of the sample in the sample to be measured is 0.1-90wt%.

Description

Analysis method for one or more sample components containing 1, 4-cyclohexanedimethanol, 1, 4-cyclohexanedicarboxylic acid dimethyl ester and terephthalic acid dimethyl ester Technical Field The invention relates to the technical field of chemical detection, in particular to an analysis method for one or more sample components containing 1, 4-cyclohexanedimethanol, 1, 4-cyclohexanedicarboxylic acid dimethyl ester and terephthalic acid dimethyl ester. Background PETG is a transparent, non-crystalline copolyester, and is the product of transesterification polycondensation of three monomers, terephthalic acid (PTA), ethylene Glycol (EG) and 1, 4-Cyclohexanedimethanol (CHDM). Unlike PET and PCT materials, PETG has outstanding toughness and high impact strength, the impact strength of the PETG is 3-10 times that of modified polyacrylate, the PETG has a wide processing range, high mechanical strength and excellent flexibility, and compared with PVC, the PETG has high transparency, good gloss, easy printing and environmental protection advantages. At present, an important monomer 1, 4-Cyclohexanedimethanol (CHDM) for preparing PETG mainly adopts a two-step hydrogenation route of dimethyl terephthalate (DMT), wherein the first step of DMT benzene ring hydrogenation is to prepare 1, 4-cyclohexanedicarboxylic acid dimethyl ester (DMCD), and the second step of DMCD hydrogenation is to prepare the CHDM. Dimethyl terephthalate (DMT) is an important raw material for the preparation of 1, 4-cyclohexanedimethanol, and dimethyl 1, 4-cyclohexanedicarboxylate (DMCD) is an important intermediate product for the preparation of 1, 4-cyclohexanedimethanol. The hydrogenated product of the dimethyl terephthalate contains various impurity components and possibly unconverted raw material dimethyl terephthalate besides the target product of the dimethyl 1, 4-cyclohexanedicarboxylate, and the hydrogenated product of the dimethyl 1, 4-cyclohexanedicarboxylate contains methanol and various impurity components and possibly unconverted raw material dimethyl 1, 4-cyclohexanedicarboxylate besides the target product of the dimethyl 1, 4-cyclohexanedimethanol. The domestic analysis of 1, 4-cyclohexanedimethanol and the raw materials and hydrogenated products thereof or samples containing or partially containing similar components is usually carried out by gas chromatography or liquid chromatography. CN111272900A discloses a gas chromatography analysis method of 3-chloro-2, 2-dimethyl-1-propanol, which comprises the steps of preparing an analysis sample, analyzing conditions of gas chromatography and qualitative and quantitative methods, wherein the chromatographic analysis conditions comprise that the sample injection amount is 1 mu L, the gas chromatography conditions comprise that the sample injection amount is kept for 4 minutes at 60 ℃, then the gas chromatography conditions comprise that the sample injection amount is kept for 10 minutes at 20 ℃ to 250 ℃, a TG-wax chromatographic column is adopted for 30m multiplied by 0.25mm multiplied by 0.25 mu m, a hydrogen flame detector is adopted, the retention time of 3-chloro-2, 2-dimethyl-1-propanol is 8.980min, the quantitative method is an internal standard method, the internal standard is 1,3, 5-trimethylbenzene, and the retention time of the internal standard is 6.650min. CN111855864A discloses a gas chromatography analysis method of dimethylcyclopropylether (2, 2-dimethyl-1, 3-epoxypropane) and neopentyl glycol (2, 2-dimethyl-1, 3-propanediol), which comprises the steps of analyzing sample configuration, gas chromatography analysis conditions and qualitative and quantitative methods, wherein the gas chromatography analysis conditions are that the sample injection amount is 1 mu L, the gas chromatography conditions are kept for 4 minutes at 60 ℃ and then kept for 10 minutes from 15 ℃ to 250 ℃ per minute, a TG-1701ms chromatographic column is adopted, the specification is 30m multiplied by 0.25mm multiplied by 0.25 mu m, the hydrogen flame detector is adopted, the residence time of the dimethylcyclopropylether is 2.278min, the residence time of the neopentyl glycol is 8.983min, the quantitative method is an internal standard method, the internal standard is ethylene glycol, and the residence time of the internal standard is 6.650min. CN113252831A discloses an ultra-high performance liquid chromatography analysis method of N-chloroformyl-N- [4- (trifluoromethoxy) phenyl ] methyl carbamate, (1) preparing a standard substance solution and a sample solution to be tested with the concentration range of 0.5-2g/L, (2) setting the detection wavelength to 210nm, sequentially sampling according to the sequence of the standard substance, the sample to be tested and the standard substance after the instrument baseline is stable, respectively calculating the peak area average value of the standard substance solution and the sample solution to be tested, and (3) calculating the content of N-chloroformyl-N-