Method for researching polyolefin resin auxiliary agent odor compound based on headspace-gas chromatography-ion mobility spectrometry technology

Abstract

The invention discloses a method for detecting an odor compound in a polyolefin resin additive. The method is specifically implemented according to the following steps: step 1, carrying out headspace-gas chromatography-ion mobility spectrometry detection on a polyolefin resin additive sample; step 2, extracting signal peaks of volatile compounds of different types of assistants through software LAV to construct a fingerprint spectrum; step 3, carrying out qualitative analysis processing on the signal peak selected in the step 2 through GC-IMS Library Search Software qualitative software, and carrying out qualitative analysis processing on the signal peak selected in the step 2 through GC-IMS Library Search Software qualitative software; and 4, taking the signal intensity of each compound in the odor compound fingerprint as a basis for comparing different types of additive odor substances. According to the invention, the volatile odor substances in different models of polyolefin resin aids can be qualitatively analyzed, and the difference of the volatile odor substances in different models of aids can be quickly analyzed and compared, so that the odor compounds can be visually monitored.

Description

Technical Field

[0001] The invention belongs to the technical field of compound detection methods, and particularly relates to a method for studying odor compounds of polyolefin resin additives based on headspace-gas chromatography-ion mobility spectrometry technology. Background Art

[0002] Polyolefin resin processing aids are chemical substances used to improve the performance of polyolefin resins during production and processing. The addition of these additives can enhance the processing properties, thermal stability, and aging resistance of polyolefin resins, thereby improving product quality and production efficiency. However, polyolefin resin additives can have inherently unpleasant odors, which can enter the finished resin during processing. With the development of the polyolefin resin materials industry, the demand for new, low-odor, and clean polyolefin resin materials is growing. Therefore, obtaining information on odorous substances in these processing aids can provide data support for the development of new polyolefin resins.

[0003] In recent years, the automotive industry has used manual olfaction to evaluate the odor levels of polyolefin materials. This method can preliminarily distinguish the odor levels of materials, but cannot accurately perform qualitative analysis of odor compounds. The odor level graduation values ​​are large, and the odor detection is too general. GC-O-MS technology was used to detect automotive polypropylene composite materials, and it was found that the burnt odor produced by the material was the result of the combined effect of alkanes and aldehydes and ketones on the sense of smell. However, due to the human subjectivity of olfaction technology, there are certain differences in the identification of odor composition. Although solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) can achieve qualitative analysis of odor compounds in additives and trace detection of odor compounds in samples, the detection process of this method is cumbersome, not only taking a long time to detect samples, but also requiring a lot of time for data processing.

[0004] Due to the complex composition of volatile compounds in additive materials, comparative analysis of odor components between samples is a cumbersome process. Gas chromatography-ion mobility spectrometry (GC-IMS) combines gas chromatography with ion mobility spectrometry. After initial separation by GC, the sample enters the IMS, where it is further analyzed under the influence of an electric field. GC-IMS detects the sample without the need for sample enrichment or other pretreatment. Volatile components in the sample undergo multiple separations by GC and IMS, achieving multidimensional separation of the volatile components with high resolution and resolution. Compared to volatile component detection techniques such as GC-MS and GC-O, GC-IMS requires simple sample pretreatment and offers higher sensitivity, resolution, and resolution. Furthermore, its data processing software, LAV, enables visual comparison of odor compounds in different samples, significantly reducing the time, effort, and effort required to analyze differences between samples. Currently, GC-IMS has not been well-approved for detecting odor compounds in polymer materials such as polyolefin resins and polyolefin resin additives. Summary of the Invention

[0005] The present invention aims to provide a method for analyzing odorous compounds in polyolefin resin additives using headspace-gas chromatography-ion mobility spectrometry. This method qualitatively characterizes volatile odorous compounds in different types of polyolefin resin additives, rapidly analyzes and compares the differences in volatile odorous compounds among these additives, and enables visual monitoring of odorous compounds. The developed method features simple pretreatment, a short detection cycle, high sensitivity, separation, and resolution, and allows for visual monitoring.

[0006] The technical solution adopted by the present invention is a method for studying odor compounds of polyolefin resin additives based on headspace-gas chromatography-ion mobility spectrometry technology, which is specifically implemented according to the following steps:

[0007] Step 1. Detecting the polyolefin resin additive by headspace-gas chromatography-ion mobility spectrometry;

[0008] Step 2. Use the software LAV to extract the signal peaks of volatile compounds of different types of additives and construct fingerprints;

[0009] Step 3. Perform qualitative analysis on the signal peaks selected in step 2 using GC-IMS Library Search Software;

[0010] Step 4. Use the signal intensity of each compound in the odor compound fingerprint as the basis for comparing the odor substances of different types of additives.

[0011] The present invention is also characterized in that:

[0012] The headspace conditions in step 1 are as follows: weigh 2 g of polyolefin resin additive sample into a headspace bottle, incubate at 60° C., incubate at 500 rpm for 30 min, take 500 μL of headspace gas, and perform automatic headspace sampling.

[0013] The ion mobility spectrometry conditions in step 1 were: inlet temperature of 85°C, carrier gas of 99.99% purity nitrogen, and flow rate program of 2 mL / min for 2 min, 20 mL / min for 8 min, 100 mL / min for 10 min, and 150 mL / min for 40 min.

[0014] The chromatographic column in step 1 is a FS-SE-54-CB-1 capillary column with a specification of 15m×0.53mm×1μm, the column temperature is 40°C, the operating temperature of the ion migration tube is 45°C, the nitrogen flow rate is 150mL / min, the data acquisition is in positive ion mode, and C4~C9 ketones are used as external standard references.

[0015] In step 3, the drift time, retention index, and retention time in the built-in NIST14 database of the GC-IMS Library Search Software instrument software are used to perform qualitative analysis of the substance.

[0016] In step 4, the differences in odor compounds between samples are visualized and analyzed based on the qualitative results and the constructed fingerprint.

[0017] The intensity of each signal peak in the fingerprint spectrum is expressed as follows: the intensity of the odor substance with the highest content in the additive is set as 100, and the intensity of other compounds is the ratio to 100.

[0018] The beneficial effects of the present invention are that, based on the headspace-gas chromatography-ion mobility spectrometry technology, a method for studying the odor compounds of polyolefin resin additives is provided, and the GC-IMS technology is applied to the odor analysis of polyolefin resins and other related materials. Not only is the sample pretreatment simple, without the need for complex pretreatment, the detection cycle is short, and the sensitivity, separation and resolution are high, but also, through the acquired fingerprint spectrum, the odor compound differences of different samples can be compared and analyzed, and visual monitoring can be performed, thereby reducing the difficulty of differential analysis of different samples, and providing a new method for the rapid detection and comparative analysis of odor compounds of various polyolefin resins and other materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a GalleryPlot of volatile organic compounds in three different types of polyolefin resin additives in Example 1 of the present invention;

[0020] Figure 2This is a GalleryPlot diagram of volatile organic compounds in four different types of polyolefin resin additives in Example 2 of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] The present invention is based on the headspace-gas chromatography-ion mobility spectrometry technology to study the odor compounds of polyolefin resin additives, which is specifically implemented according to the following steps:

[0023] Step 1. Detecting the polyolefin resin additive by headspace-gas chromatography-ion mobility spectrometry;

[0024] The headspace conditions in step 1 are as follows: weigh 2 g of polyolefin resin additive sample into a headspace vial, incubate at 60°C, 500 rpm for 30 min, take 500 μL of headspace gas, and perform automatic headspace sampling;

[0025] The ion mobility spectrometry conditions in step 1 were as follows: inlet temperature of 85°C, carrier gas of 99.99% purity nitrogen, flow rate program of 2 mL / min for 2 min, 20 mL / min for 8 min, 100 mL / min for 10 min, and 150 mL / min for 40 min, with a total run time of 60 min;

[0026] The chromatographic column in step 1 was a FS-SE-54-CB-1 capillary column with specifications of 15 m × 0.53 mm × 1 μm. The column temperature was 40°C, the operating temperature of the ion migration tube was 45°C, the nitrogen flow rate was 150 mL / min, and data acquisition was in positive ion mode. C4-C9 ketones were used as external standards.

[0027] Step 2. Use the software LAV to extract the signal peaks of volatile compounds of different types of additives and construct fingerprints;

[0028] The HS-GC-IMS test results of the additives were analyzed using LAV software, and the signal peaks of volatile compounds in the samples were selected to construct the fingerprint spectrum of the odor compounds of the polyolefin resin additives;

[0029] Step 3. Perform qualitative analysis on the signal peaks selected in step 2 using GC-IMS Library Search Software;

[0030] The signal peaks extracted in step 2 were qualitatively analyzed based on DT (drift time), RI (retention index), and RT (retention time) using the built-in NIST14 database in the GC-IMS Library Search Software.

[0031] Step 4. The signal intensity of each compound in the odor compound fingerprint is used as the basis for comparing the odor substances of different types of additives;

[0032] In step 4, the qualitative results are combined with the constructed fingerprint to achieve a visual analysis of the differences in odor compounds between samples;

[0033] The intensity of each signal peak in the fingerprint spectrum is expressed as follows: the intensity of the odor substance with the highest content in the additive is set as 100, and the intensity of other compounds is the ratio to 100.

[0034] Example 1

[0035] The method for studying the odor compounds of polyolefin resin additives based on headspace-gas chromatography-ion mobility spectrometry technology is specifically implemented according to the following steps:

[0036] Step 1. HS-GC-IMS analysis

[0037] 2g of three different types of additives were taken for headspace-gas chromatography-ion mobility spectrometry analysis;

[0038] The headspace conditions were as follows: the polyolefin resin additive sample was placed in a headspace bottle, incubated at 60°C and 500 rpm for 30 min, 500 μL of headspace gas was taken, and automatic headspace sampling was performed;

[0039] The ion mobility spectrometry conditions were as follows: inlet temperature of 85°C, carrier gas of 99.99% purity nitrogen, flow rate program of 2 mL / min for 2 min, 20 mL / min for 8 min, 100 mL / min for 10 min, and 150 mL / min for 40 min, with a total run time of 60 min;

[0040] The chromatographic column was a FS-SE-54-CB-1 capillary column with specifications of 15 m × 0.53 mm × 1 μm. The column temperature was 40°C, the operating temperature of the ion migration tube was 45°C, and the nitrogen flow rate was 150 mL / min.

[0041] Data acquisition was in positive ion mode, using C4–C9 ketones as external standards;

[0042] Step 2. HS-GC-IMS detection obtains volatile compound data in the sample, extracts the signal peaks of the volatile compounds of each additive using LAV software, and constructs a fingerprint of the volatile compounds of the polyolefin resin additive;

[0043] Step 3. Perform qualitative analysis on the signal peaks extracted by LAV in step 2 using GC-IMS Library Search Software. Qualitative analysis of the substances is performed based on DT (drift time), RI (retention index), and RT (retention time) in the NIST14 database. After removing dimers and polymers, the GC-IMS qualitative results are obtained by classifying the compounds according to their types.

[0044] Step 4. Based on the fingerprint of volatile compounds of polyolefin resin additives constructed in step 2 and the qualitative results, compare and analyze the odor compounds between different samples, and compare and analyze the odor compounds of different types of additives based on the qualitative fingerprint and compound signal intensity.

[0045] The qualitative results are shown in Table 1 below. A total of 54 odor compounds were detected in the three additives, of which 43 could be qualitatively identified, while 11 volatile compounds remained unidentified. The compounds included aldehydes, esters, alcohols, ketones, acids, benzene series, and alkanes.

[0046] Table 1 GC-IMS qualitative results of volatile compounds of three additives

[0047]

[0048]

[0049]

[0050] like Figure 1 The following are the fingerprints of odor compounds obtained by detecting three kinds of additives. Combined with the strength of the response signals of each compound in the sample in Table 2 below, the differences in odor compounds between samples are analyzed.

[0051] Table 2 Signal intensity of odor compounds of three additives

[0052]

[0053]

[0054]

[0055]

[0056] There are 14 odor compounds detected in all three adjuvant samples. Figure 1 The parts marked with red boxes include acrolein, butyl acetate, n-hexanol, butyl acetate, butyraldehyde, propyl butyrate, 2-propanol, 2-hexanol, sarin, methyl 3-methylbutyrate, 2-methylthiophene, 3-pentanone, 4, and 2. Two compounds were not identified.

[0057] The detection amounts of 1-pentanol, ethyl acetate, n-hexanol, 2-hexanol, 2-heptanone, acetic acid and three uncharacterized compounds 6, 7 and 8 in 7011 additive were much higher than those in the other two additives. The above compounds can be regarded as the characteristic odor substances of 7011 additive.

[0058] Similarly, 2-butanone, 2-octanone, 2-octanone, methyl butyrate, cyclohexanone, 2-methylpropanol, 3-methylbutanal, 2-methylpropanol, unidentified 12, p-xylene, and 2-pentanone are the characteristic odor substances of GX-48blue additive.

[0059] p-Xylene, methylpyrazine, furfuryl alcohol, 2-methyl-1-butanol, propionic acid, 1-hydroxy-2-propanone, 2-pentanone, propionic acid, 2-heptanone, methylpyrazine, valeraldehyde, and 1-methoxy-2-propanol are the characteristic odor substances of JHC-7531 adjuvant.

[0060] Example 2

[0061] A method for studying odor compounds in polyolefin resin additives based on headspace-gas chromatography-ion mobility spectrometry technology was used. Four different types of additives were selected for testing. The specific steps were the same as those in Example 1.

[0062] The qualitative results are shown in Table 3 below. A total of 45 volatile compounds were identified in the four additive samples, of which 37 odor compounds could be qualitatively identified and 8 volatile compounds remained unidentified. The compounds included aldehydes, esters, alcohols, ketones, acids, benzene series, and alkanes.

[0063] Table 3 GC-IMS qualitative results of volatile compounds of four additives

[0064]

[0065]

[0066]

[0067] Figure 2 The fingerprints of odor compounds obtained from the detection of four auxiliary agents are combined with the strength of the response signals of each compound in the samples in Table 4 below to analyze the differences in odor compounds among the samples.

[0068] Table 4 Signal intensity of four additive odor compounds

[0069]

[0070]

[0071]

[0072]

[0073] There are 9 odor compounds detected in all four additive samples. Figure 2 The parts marked with red boxes are butyraldehyde, butyl acetate, sarin, cyclohexanone, butyl acetate, propyl butyrate, 2-furylthiol, benzoic aldehyde, and n-hexanol.

[0074] Ethyl acetate, propionic acid, 2-pentanone, 2-methylpropionic acid, pentan-1-ol, methyl 3-methylbutyrate, cyclohexanone, 2-heptanone, 2-octanone, methyl butyrate, 1-butyl, 2-pentanone, benzoic aldehyde, furfuryl alcohol, p-xylene, 2-octanone, 5, 9 were only detected in the GX-48white model additive. They were not detected in the other three models of additives or the detection signals were very small. The above compounds can be used as characteristic odor substances of the GX-48white model additive.

[0075] Similarly, 1-propanol, propionic acid, and 1-methoxy-1-propanol are characteristic odor substances of JHC-7531 additive. 2-Methylpropanol, butyric acid, p-xylene, 2-methylthiophene, styrene, 3-methylbutyraldehyde, 11, and 12 are characteristic odor substances of EP100N additive.

[0076] In summary, the application of headspace-gas chromatography-ion mobility spectrometry (HGS) to the detection of odorous compounds in polyolefin resin additives demonstrates its high sensitivity, high resolution, lack of pretreatment, simplicity of operation, short analysis time, and low cost. This allows for rapid detection of odorous compounds in polyolefin resin additives. The fingerprints generated by the LAV software can be compared and analyzed to visualize the differences in odorous compounds between samples. Establishing a method for studying odorous compounds in polyolefin resin additives based on HGS can provide data support and theoretical guidance for the development of new, low-odor, clean polyolefin resin materials.

Claims

1. A method for studying odor compounds in polyolefin resin additives based on headspace-gas chromatography-ion mobility spectrometry technology, characterized in that: Please follow the steps below to implement: Step 1. Detecting the polyolefin resin additive by headspace-gas chromatography-ion mobility spectrometry; Step 2. Use the software LAV to extract the signal peaks of volatile compounds of different types of additives and construct fingerprints; Step 3. Perform qualitative analysis on the signal peaks selected in step 2 using GC-IMS Library Search Software; Step 4. Use the signal intensity of each compound in the odor compound fingerprint as the basis for comparing the odor substances of different types of additives.

2. The method for studying odor compounds of polyolefin resin additives based on headspace-gas chromatography-ion mobility spectrometry technology according to claim 1, characterized in that: The headspace conditions in step 1 are as follows: 2 g of polyolefin resin additive sample is weighed into a headspace bottle, the incubation temperature is 60° C., incubated at 500 rpm for 30 min, 500 μL of headspace gas is taken, and automatic headspace sampling is performed.

3. The method for studying odor compounds of polyolefin resin additives based on headspace-gas chromatography-ion mobility spectrometry technology according to claim 1, characterized in that: The ion mobility spectrometry conditions in step 1 are as follows: the injection port temperature is 85° C., the carrier gas is nitrogen with a purity of 99.99%, and the flow rate program is: 2 mL / min for 2 min, 20 mL / min for 8 min, 100 mL / min for 10 min, and 150 mL / min for 40 min.

4. The method for studying odor compounds of polyolefin resin additives based on headspace-gas chromatography-ion mobility spectrometry technology according to claim 1, characterized in that: The chromatographic column in step 1 is a FS-SE-54-CB-1 capillary column with a specification of 15m×0.53mm×1μm, the column temperature is 40°C, the operating temperature of the ion migration tube is 45°C, the nitrogen flow rate is 150mL / min, the data acquisition is in positive ion mode, and C4~C9 ketones are used as external standard references.

5. The method for studying odor compounds of polyolefin resin additives based on headspace-gas chromatography-ion mobility spectrometry technology according to claim 1, characterized in that: The step 3 is to perform qualitative analysis on the substance using the drift time, retention index, and retention time in the NIST14 database built into the GC-IMS Library Search Software instrument supporting software.

6. The method for studying odor compounds of polyolefin resin additives based on headspace-gas chromatography-ion mobility spectrometry technology according to claim 1, characterized in that: In step 4, the differences in odor compounds between samples are visually analyzed based on the qualitative results combined with the constructed fingerprint.

7. The method for studying odor compounds of polyolefin resin additives based on headspace-gas chromatography-ion mobility spectrometry technology according to claim 1, characterized in that: The intensity of each signal peak in the fingerprint spectrum is represented by setting the intensity of the odorant with the highest content in the additive to 100, and the intensity of other compounds to 100.

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