Screening method for volatile and semi-volatile odor markers in raw and auxiliary materials of paper presswork

Abstract

The invention belongs to the technical field of analysis and detection, and particularly relates to a method for screening volatile and semi-volatile odor markers in raw and auxiliary materials of paper printed matters. The data obtained by the headspace solid-phase microextraction gas chromatography / mass spectrometry is qualitatively analyzed on the basis of a triple confirmation mechanism constructed by a deconvolution method, a matching degree method and a retention index method, and the problem of inaccurate qualitative analysis in a complex matrix is solved. In the semi-quantitative analysis, compounds with different polarities are used as internal standard substances, and a calibration strategy is optimized according to the polarity difference of a target object, so that the reliability of an analysis result is improved. In addition, the components of the odor activity values are subjected to intersection analysis to screen out key odor markers. According to the model, the risk of misjudgment of high-concentration low-threshold substances in a traditional method is avoided by quantifying the contribution degree of a single component to the overall smell.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of analytical detection, and particularly relates to an analysis method for screening odor markers in paper printing materials. BACKGROUND

[0002] The sensory quality of a product is one of the key factors for consumer acceptance, and the migration behavior of volatile and semi-volatile organic compounds (VOCs / SVOCs) in packaging materials has become a core problem affecting the odor stability of products. Studies have shown that aldehydes (such as hexanal) adsorbed by paper fibers, benzene series solvents (such as toluene, ethylbenzene) left by ink residues, and esters (such as ethyl acetate) released by adhesives can migrate from product packaging to product body through gas phase diffusion, resulting in the generation of odor or the covering of characteristic aroma. In recent years, with the strict control of packaging material safety by various industry regulations, the development of high-precision analysis methods to identify odor active ingredients and guide material screening has become a technical bottleneck that needs to be broken through for the green transformation of industry.

[0003] Markers, especially biomarkers, refer to specific molecular entities that can objectively indicate the dynamic changes of a biological system under physiological, pathological or pharmacological intervention through quantitative or qualitative detection. Based on the differentiated characteristics of gravure printing, offset printing, flexible printing and other process systems, the supporting raw and auxiliary material systems present significant specificity. Taking the gravure printing process as an example, its special ink system is usually composed of film-forming resin, coloring pigment, volatile solvent and functional filler. The selection of solvent needs to strictly follow the national / industry standard specifications such as GB38507-2020 "Limit of volatile organic compounds (VOCs) content in ink", and the volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) produced thereby have traceable volatile properties. By systematically analyzing the mass spectrum fingerprint of such process characteristic odor components, a raw material component consistency evaluation model can be established, and then material batch stability monitoring and safety early warning can be realized. The above characteristic VOCs / SVOCs can be used as key odor markers for the quality traceability of printed matter due to their process correlation and detection sensitivity advantages.

[0004] Patent No. 202410895285.3 discloses a method for analyzing the smell of tipping paper for cigarettes, which is used to judge whether the tipping paper can be applied in cigarettes. The method uses Heracles Neo fast gas-phase electronic nose system to analyze the smell signal intensity of tipping paper for cigarettes, judges whether the tipping paper for cigarettes has odor through the signal intensity range of the smell of tipping paper for cigarettes, and further judges whether the tipping paper can be applied in cigarettes. The disadvantages of the prior art are: first, the traditional qualitative method relies on single mass spectrum library matching, and the phenomenon of multiple components co-flowing causes characteristic ion superposition, resulting in misidentification of compounds. Second, the existing semi-quantitative analysis usually uses a single internal standard, which is difficult to adapt to the polarity difference of target substances. Especially for complex samples, a single internal standard cannot effectively correct a wide polarity range in different polarity compounds. In addition, the current odor substance screening standard usually uses absolute concentration or sensory threshold as the criterion, ignoring the dynamic contribution between compound concentration and sensory threshold. For example, low concentration but ultra-low threshold (0.1 μg / kg) β-damascone may have a dominant influence on the overall odor profile. The above bottlenecks seriously restrict the scientificity and reliability of the odor quality control system. SUMMARY

[0005] Based on the above technical problems, the present application provides an analysis method for screening and identifying odor component markers in paper printing raw materials, which is realized by the following technical solutions:

[0006] A screening method for volatile and semi-volatile odor markers in paper printing raw materials, comprising the following steps: using headspace solid-phase microextraction gas chromatography / mass spectrometry technology to qualitatively analyze the odor components in paper printing raw materials, obtaining the types of odor components; using a multi-polarity internal standard system composed of deuterated naphthalene, pentyl acetate and cyclopentanone, semi-quantitative analysis is carried out by internal standard method, and the relative content of each odor component is obtained; the odor activity value of each odor component is calculated one by one, and the components with odor activity value greater than or equal to 1 are selected as effective odor components; the intersection analysis of the effective odor components is carried out, and the gas markers are obtained.

[0007] As a preferred, the screening method further comprises: in the qualitative analysis stage, after splitting the overlapping chromatographic peaks in the complex matrix by deconvolution method, the spectrum matching is carried out by combining NIST mass spectrum database, and the types of each odor component are confirmed.

[0008] As a preferred, the step of qualitative analysis comprises: using Agilent unknown substance analysis software to deconvolute the co-elution peaks in the chromatogram, separating the overlapping chromatographic peaks; the results obtained by deconvolution are matched with NIST mass spectrum library for similarity, and the types of each odor component are confirmed.

[0009] As preferred, the qualitative analysis comprises: screening out the odor components with matching degree higher than 75% as the basis of semi-quantitative analysis.

[0010] As preferred, in the qualitative analysis stage, the odor components are verified by retention index matching degree.

[0011] As preferred, the step of qualitative analysis comprises: determining the n-alkane series standard under the same chromatographic conditions, calculating the retention index of the odor components based on the retention time, and cross-checking with the reference retention index data in the NIST mass spectrum database to confirm the type of the odor components.

[0012] As preferred, the intersection analysis comprises: using upset graph to conduct intersection analysis on the components with odor activity value greater than or equal to 1, and taking the odor components detected in both the paper printing material and the finished product as the gas marker.

[0013] As preferred, in the headspace solid-phase microextraction gas chromatography / mass spectrometry, the extraction head is 50 / 30 mu m DVB / CAR / PDMS.

[0014] As preferred, in the headspace solid-phase microextraction gas chromatography / mass spectrometry, the fixed extraction time is 10-50 min, the temperature is 50-90 DEG C, and the equilibrium time is 10-50 min.

[0015] As preferred, in the headspace solid-phase microextraction gas chromatography / mass spectrometry, the split ratio is (2-10):1.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] To accurately identify the key odor components in the raw and auxiliary materials of paper printed matter and establish the basis for quality control, the present application constructs a set of systematic analysis method integrating multi-dimensional qualitative, semi-quantitative by polarity and threshold screening, and finally establishes typical odor markers. From the qualitative aspect, after splitting the overlapping chromatographic peaks by deconvolution method, cross-validation of mass spectrum is carried out combined with NIST mass spectrum database, and a three-dimensional qualitative confirmation mechanism is constructed by introducing retention index matching, which ensures the accurate and reliable identification of the types of odor components, effectively solving the problem of inaccurate odor component identification under complex matrix; from the semi-quantitative aspect, deuterated naphthalene, pentyl acetate and cyclopentanone are selected to form an internal standard system, and the dielectric constant is used as the screening basis to match the internal standard with stronger applicability for odor substances of different polarity, effectively overcoming the systematic deviation caused by the difference in polarity of target substances in traditional semi-quantitative method, and improving the accuracy of concentration estimation; from the marker screening aspect, based on the relative odor activity value (rOAV), the components with rOAV≥1 (i.e. having actual contribution to the overall odor) are screened out, and then the intersection analysis is carried out by Upset graph, and finally the key odor markers are screened out. This process successfully avoids the misjudgment risk of traditional methods for high-concentration but low-odor activity substances by quantifying the contribution of single component to the overall odor, ensuring that the screened markers have both sensory influence and practicality for control. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings will be briefly introduced as follows:

[0019] Figure 1 (A) 5 kinds of SPME extraction head extraction effect diagram; (B) extraction effect of different equilibrium time; (C) extraction effect of different equilibrium temperature; (D) extraction effect of different extraction time;

[0020] Figure 2 is the distribution diagram of odor components in 3 kinds of products and their raw and auxiliary materials;

[0021] Figure 3 is the upset analysis diagram of Sample01;

[0022] Figure 4 is the upset analysis diagram of Sample02;

[0023] Figure 5 is the upset analysis diagram of Sample03. DETAILED DESCRIPTION

[0024] The application will be further described in the following specific examples. A person of ordinary skill in the art can implement the application based on these descriptions. In addition, the examples of the application involved in the following description are generally only a part of the examples of the application, not all examples. Therefore, all other examples obtained by a person of ordinary skill in the art based on the examples in the application without creative labor should be within the scope of protection of the application.

[0025] Example 1

[0026] This example carries out experiments around the optimization of pretreatment process and conditions to improve the extraction efficiency and accuracy of odor components. The specific experimental process is as follows:

[0027] 1.1 Solution preparation

[0028] Internal standard solution preparation: Take deuterated naphthalene, cyclopentanone and pentyl acetate, and use triacetin to prepare an internal standard solution with a concentration of 1 mg / mL.

[0029] N-alkane solution preparation: Take n-alkane mixed standard (1000 mg / L), and use n-hexane to prepare a n-alkane working solution with a concentration of 10 mg / L.

[0030] 1.2 Sample pretreatment

[0031] 1.2.1 Paper printed matter, aluminum and paper printed matter base sample

[0032] Accurately cut the paper printed matter sample with an area of 121 cm 2 , and put the cut sample into a headspace bottle with the printed surface inside, add 60 μL of internal standard solution, immediately seal and perform instrument analysis. Each sample is detected in triplicate (n=3).

[0033] 1.2.2 Ink sample

[0034] The corresponding paper printed matter base is used as the sample matrix after being baked at 80°C for 2 h to ensure that the volatile / semi-volatile substances of the base are completely volatilized. The ink is developed on the above sample matrix by intaglio printing, offset printing and screen color developing instrument. Accurately cut the developed sample with an area of 121 cm 2 , and put the cut sample into a headspace bottle with the printed surface inside, add 60 μL of internal standard solution, immediately seal and perform instrument analysis. Each sample is detected in triplicate (n=3).

[0035] 1.2.3 Glue sample

[0036] The sample matrix was prepared by baking the corresponding paper printing original paper at 80°C for 2h to ensure that the volatile / semi-volatile substances in the original paper were completely volatilized. After coating the glue on the above sample matrix by a glue coating instrument, the color developing sample with an area of 121 cm 2 was accurately cut, and the cut sample was rolled into a cylinder with the printing surface inside and placed in a headspace bottle. 60μL of internal standard solution was added, and the bottle was immediately sealed for instrument analysis. Each sample was tested in triplicate (n=3).

[0037] 1.3 Optimization of SPME extraction conditions

[0038] 1.3.1 Optimization of extraction head type

[0039] The extraction effects of different extraction heads on odor substances were significantly different. In this study, five types of extraction heads, including 75μm CAR / PDMS, 50 / 30μm DVB / CAR / PDMS, 85μm PA, 100μm PDMS, and 65μm PDMS / DVB, were tested. The extraction efficiency of the extraction head was optimized by comparing the peak number and peak area of volatile / semi-volatile components. The results showed that the peak number and area of 50 / 30μm DVB / CAR / PDMS were better than those of the other four types. Since it used a composite polymer material, it could capture polar, non-polar, and moderately polar compounds, and could more comprehensively reflect the extraction of volatile / semi-volatile substances. Therefore, it was selected for subsequent experiments.

[0040] 1.3.2 Optimization of equilibrium time

[0041] Using DVB / CAR / PDMS as the extraction head, the extraction time was fixed at 40min and the extraction temperature was fixed at 80°C for optimization experiments. The effects of equilibrium times of 10, 20, 30, 40, and 50min on the peak number and peak area were investigated, and the results are shown in Figure 1 (B). When the equilibrium time was 30min, the peak number and peak area reached a relatively large value, so the optimal equilibrium time was determined to be 30min.

[0042] 1.3.3 Optimization of equilibrium temperature

[0043] Under the conditions of a fixed equilibrium time of 30min and an extraction time of 40min, the extraction temperature optimization experiment was carried out. The effects of five temperature gradients of 50, 60, 70, 80, and 90°C on the peak number and peak area were investigated. The results are shown in Figure 1 (C). The peak number and peak area at 80°C were significantly better than those at other temperatures, so 80°C was determined as the optimal equilibrium temperature.

[0044] 1.3.4 Optimization of extraction time

[0045] The optimization experiment was carried out with 30 min equilibrium time and 80°C extraction temperature as fixed conditions, and the effects of 10, 20, 30, 40 and 50 min extraction time on the number of peaks and peak area were investigated. The results are shown in Table 1. Figure 1 As shown in Table 1, the number of peaks and the total peak area reached the maximum value when the extraction time was 40 min, so the optimal extraction time was determined to be 40 min.

[0046] 1.3.5 Split ratio optimization

[0047] The experiments were carried out without splitting, with a split ratio of 2:1 and 10:1. The results showed that the noise was significant in the non-split mode, and some substances had flat peaks, indicating that the detector was saturated due to high concentration. When the split ratio was 10:1, the signal of low content odorants was covered by the baseline noise, which was not conducive to qualitative identification and quantitative detection. When the split ratio was 2:1, the chromatographic peak shape was symmetrical and the background noise was low. Therefore, a split ratio of 2:1 was determined for subsequent experiments.

[0048] 1.4 Instrument conditions

[0049] 1.4.1 Chromatographic conditions

[0050] A DB-WAX column with specifications of 60 m x 0.320 μm x 0.25 μm was used as the analysis column; the injection port temperature was set to 250°C; the carrier gas was helium (purity ≥ 99.999%) in constant flow mode with a flow rate of 1.2 mL / min; the split ratio of the injection port was 2:1; the temperature program conditions were as follows: initial temperature 40°C, holding for 2 min; increasing the temperature to 200°C at a rate of 4°C / min, holding for 1 min; increasing the temperature to 240°C at a rate of 10°C / min, holding for 10 min.

[0051] 1.4.2 Mass spectrometry conditions

[0052] The transfer line temperature, ion source temperature and quadrupole temperature were set to 250°C, 230°C and 150°C respectively; the measurement mode was mass spectrometry full scan in the range of 33-500 amu.

[0053] 1.4.3 Solid phase extraction conditions

[0054] The equilibrium time was set to 30 min; the extraction time was set to 40 min; the equilibrium temperature was set to 80°C; and the desorption time was set to 10 min.

[0055] Example 2

[0056] In this example, qualitative analysis of data was carried out, and the specific process was as follows:

[0057] 1.1 Retention index calculation

[0058] Take 100 μL, 10 mg / L of n-alkane solution into the headspace bottle, seal quickly, test the sample according to the instrument conditions in Example 1, Part 1.4, and record the retention time of each component of the n-alkane. Calculate the retention index (RI) of each component in the n-alkane according to formula (1).

[0059]

[0060] wherein n is the carbon number of the n-alkane; t X is the retention time of the measured substance; t n is the retention time of the n-alkane with carbon number n; t n+1 is the retention time of the n-alkane with carbon number n+1.

[0061] 1.2 Qualitative analysis

[0062] The co-eluted peaks are separated by a deconvolution algorithm, and the qualitative analysis is triple-confirmed by cross-verification with the NIST mass spectrum database and retention index matching. The specific analysis steps are as follows: (1) use Agilent unknown analysis software to deconvolute the co-eluted peaks in the chromatogram to separate the overlapping components; (2) match the results obtained by deconvolution with the NIST20 standard spectrum library, and select candidate compounds with a matching score higher than 75%. Based on the spectral characteristics, secondary verification is carried out to improve the reliability of the qualitative results; (3) determine the n-alkane series standard under the same chromatographic conditions, calculate the retention index (RI) of the candidate compounds in step (2) based on their retention times, and cross-check with the reference retention index data in the NIST20 library, and finally complete the qualitative identification of the compounds.

[0063] Example 3

[0064] In this example, quantitative analysis of data, identification of odor substances, and screening of odor markers were carried out, and the specific process was as follows:

[0065] 1.1 Selection principles of internal standard substances

[0066] The existing semi-quantitative correction strategy based on a single internal standard has obvious limitations. When the polarity difference between target analytes is significant, a single internal standard cannot accurately simulate the behavior differences of all analytes during sample pretreatment (such as extraction, purification) and chromatographic separation, resulting in systematic deviations in the recovery rates or instrument response factors of different polar target substances, thereby introducing quantitative errors, reducing the reliability of the results, and restricting the applicability of the method in complex matrix systems.

[0067] To this end, the present study selects deuterated naphthalene, pentyl acetate and cyclopentanone as internal standard systems for semi-quantitative analysis of odor components in raw and auxiliary materials. The applicant found that this combination has high adaptability to the chemical properties of the odor components of trademark paper, and the above-mentioned internal standards were not detected in the blank matrix and trademark paper samples.

[0068] For the detection of odor components, the internal standard matching is screened according to the molecular structure and dielectric constant (ε). As a key parameter for quantifying molecular polarity, the physical nature of dielectric constant (ε) reflects the ability of a substance to resist external electric field polarization response—polar molecules weaken the electric field through dipole-dipole interaction, and this ability increases significantly with the increase of molecular polarity, which is manifested as an increase in ε value. In this study, by comparing the dielectric constants (ε) of each odor component and the three internal standards, the internal standard type is assigned based on the principle of polarity matching.

[0069] 1.2 Quantitative analysis

[0070] The relative concentration of the compound is calculated by the concentration of the internal standard compound, the peak area of the internal standard, and the peak area of the compound. Formula (2) is used for calculation:

[0071]

[0072] Where C i is the compound concentration, C ISTD is the internal standard solution concentration, A i is the compound peak area, and A ISTD is the internal standard peak area.

[0073] 1.3 Identification of key odor components

[0074] Screening for compounds with odor, finding the threshold value of odor compounds, and calculating the relative odor activity value (rOAV) by formula (3)

[0075]

[0076] Where OAV i is the odor activity value of the compound, C i is the relative concentration of the compound, and OT i is the recognition threshold of the compound. When the calculated value is ≥1, the compound contributes to the odor, and when the calculated value is ≥10, it is an important odor substance.

[0077] Based on the qualitative identification results and the established odor component-internal standard matching relationship, semi-quantitative analysis of odor components is carried out. The concentration of the target compound is calculated using the following formula (2).

[0078] In the screening of key odor components, the dynamic contribution between compound concentration and sensory threshold, i.e. OAV value, is used as the basis for screening. The relative odor activity value (rOAV) is calculated by formula (3). Generally, it is believed that substances with rOAV≥1 contribute to the overall odor, and substances with rOAV≥10 are important odor substances.

[0079] As shown in Figure 2 , the identified compounds in the three products and their raw and auxiliary materials were studied, and a total of 154 components with OAV≥1 were screened out, including 7 hydrocarbon compounds, accounting for 4.55%; 35 aldehyde compounds, accounting for 22.73%; 20 ketone compounds, accounting for 12.99%; 20 alcohol compounds, accounting for 12.99%; 16 aromatic compounds, accounting for 10.39%; 5 heterocyclic compounds, accounting for 3.25%; 30 ester compounds, accounting for 19.48%; 2 ether compounds, accounting for 1.30%; 3 amine hydrocarbon compounds, accounting for 1.95%; 1 acid compound, accounting for 0.65%; 12 phenolic compounds, accounting for 7.79%; and 3 halogenated hydrocarbon compounds, accounting for 1.95%. The results show that the aldehyde, ketone, alcohol and ester substances in the products and raw and auxiliary materials not only have high OAV values, but also have a large proportion in the odor components. These four types of substances have a greater contribution to the odor of paper printed matter.

[0080] 1.4 Analysis of key odor markers in raw and auxiliary materials

[0081] Upset chart belongs to the category of intersection analysis, and is a visualization tool designed for the analysis of data relationships in multiple sets (usually more than five groups). It presents the intersection and union patterns between sets in the form of a matrix combined with a bar chart. The upper vertical bar chart quantifies the data size under each combination relationship through height difference, and the lower binary matrix marks the participation status of different sets using dot matrix distribution. Through dot matrix distribution and connection line guidance, this chart can clearly present the overlapping characteristics and mutual exclusion rules between complex data sets, especially when analyzing the distribution of common elements and independent elements in multiple subsets.

[0082] The upset chart was used to analyze the intersection of components with rOAV≥1, and the results are shown in Figures 3-5To ensure the typicality of the screened markers, the odor compounds with high occurrence frequency and high correlation among each set were analyzed. The results showed that benzaldehyde, nonanal, acetophenone, 2-ethylhexanol and dodecanol were not only the key odor components in the mutual relationship of the material compositions in raw materials and finished products, but also the key odor components in the final product. The rOAV values of the above five components were larger, and they were detected in the three finished products and their corresponding raw materials. Therefore, they were suitable as quality markers to support the odor quality control of paper printed matter and the selection of raw materials.

[0083] In this example, the triple confirmation mechanism based on deconvolution method, matching degree method and retention index method was used to qualitatively analyze the data obtained by headspace solid phase microextraction gas chromatography / mass spectrometry (HS-SPME-GC / MS), which solved the problem of inaccurate qualitative analysis in complex matrix. In semi-quantitative analysis, different polarity compounds were used as internal standards, and the calibration strategy was optimized according to the polarity difference of target compounds, which improved the reliability of the analysis results. The results showed that based on the relative odor activity value (rOAV, i.e. the ratio of semi-quantitative concentration to chemical threshold value ≥1) as the substance contributing to the odor of the product, 154 key odor components were identified in the three paper printed matters and their raw materials, including hydrocarbons, aldehydes, ketones, alcohols, aromatic hydrocarbons, heterocyclic compounds, esters, ethers, amines, acids, phenols and halogenated hydrocarbons. Further using the intersection analysis (upset plot analysis), benzaldehyde, nonanal, acetophenone, 2-ethylhexanol and dodecanol were identified as odor markers. The screened volatile / semi-volatile odor markers provided a theoretical basis and technical support for the subsequent odor quality control of paper printed matter and the selection of raw materials.

Claims

1. A method for screening of volatile and semi-volatile odor markers in paper printing material raw materials, characterized in that, Comprising the following steps: Qualitative analysis of odor components in paper printing materials and auxiliary materials is performed by headspace solid-phase microextraction gas chromatography / mass spectrometry to obtain the types of odor components; semi-quantitative analysis is performed by internal standard method using a multi-polarity internal standard system composed of deuterated naphthalene, pentyl acetate and cyclopentanone to obtain the relative content of each odor component; the odor activity value of each odor component is calculated one by one, and components with an odor activity value greater than or equal to 1 are selected as effective odor components; intersection analysis is performed on the effective odor components to obtain the gas marker.

2. A method of screening for volatile and semi-volatile odour markers in paper printing material according to claim 1, characterized in that, Also comprising: In the qualitative analysis stage, after the overlapping chromatographic peaks in the complex matrix are separated by the deconvolution method, spectrum matching is performed in combination with the NIST mass spectrometry database to confirm the types of odor components.

3. A method of screening for volatile and semi-volatile odour markers in paper printing material according to claim 2, characterized in that, The steps of qualitative analysis include: using Agilent unknown substance analysis software to perform deconvolution processing on the co-elution peaks in the chromatogram to separate overlapping chromatographic peaks; performing similarity matching of the results obtained by deconvolution with the NIST mass spectrometry library to confirm the types of odor components.

4. A method of screening for volatile and semi-volatile odour markers in paper printing material according to claim 3, characterized in that, The steps of qualitative analysis include: selecting odor components with a matching degree higher than 75% as the basis for semi-quantitative analysis.

5. A method of screening for volatile and semi-volatile odor markers in paper printing material raw materials according to claim 1, characterized in that, Also comprising: In the qualitative analysis stage, the odor components are verified by retention index matching degree.

6. A method of screening for volatile and semi-volatile odour markers in paper printing material raw materials according to claim 5, characterized in that, The steps of qualitative analysis include: determining the n-alkane series standard under the same chromatographic conditions, calculating the retention index of the odor component based on the retention time, and cross-checking with the reference retention index data in the NIST mass spectrometry database to confirm the type of odor component.

7. A method of screening for volatile and semi-volatile odour markers in paper printing material raw materials according to claim 1, characterized in that, The intersection analysis includes: using upset graph to perform intersection analysis on components with an odor activity value greater than or equal to 1, and using the fragrance components detected in paper printing materials and auxiliary materials and finished products as the gas marker.

8. A method of screening for volatile and semi-volatile odour markers in paper printing material raw materials according to claim 1, characterized in that, In headspace solid-phase microextraction gas chromatography / mass spectrometry, the extraction head is 50 / 30 μm DVB / CAR / PDMS.

9. A method of screening for volatile and semi-volatile odour markers in paper printing material raw materials according to claim 1, characterized in that, In headspace solid-phase microextraction gas chromatography / mass spectrometry, the fixed extraction time is 10-50 min, the temperature is 50-90℃, and the equilibrium time is 10-50 min.

10. A method of screening for volatile and semi-volatile odour markers in paper printing material raw materials according to claim 1, characterized in that, In headspace solid-phase microextraction gas chromatography / mass spectrometry, the split ratio is (2-10):1.

Images