Method for rapidly identifying types of yellow spots on surface of cigarette by using infrared spectrum

Abstract

The invention discloses a method for rapidly identifying the type of yellow spots on the surface of a cigarette by using an infrared spectrum, and relates to the field of tobacco and cigarette products, and the method comprises the following steps: cutting a cigarette paper sample with yellow spots from cigarette paper of a yellow spot cigarette as a yellow spot sample; a cigarette paper sample without yellow spots is cut from the blank cigarette paper outside the yellow spot area to serve as an out-spot cigarette paper sample; the method comprises the following steps: respectively placing a yellow spot sample and an out-spot cigarette paper sample in an ATR part of an attenuated total reflection infrared spectrometer, collecting ATR-FTIR spectral data of the samples, and calculating an A value; comparing the A value of the macular sample and the A value of the out-of-spot cigarette paper sample with a database, performing auxiliary judgment by combining with the characteristic peak form, and judging the type of the macular according to a comparison result.

Description

Technical Field

[0001] This invention relates to the field of tobacco and cigarette products, and particularly to the field of manufacturing process control and quality inspection of tobacco and cigarette products, specifically a method for rapidly identifying the type of yellow spots on the surface of cigarettes using infrared spectroscopy. Background Technology

[0002] Yellow-spotted cigarettes refer to cigarettes with yellowish-brown spots on their surface. This is usually caused by improper conditions during cigarette production or storage. According to the national standard GB5606.3-2005 "Cigarettes Part 3: Packaging, Rolling Technical Requirements and Storage and Transportation," the appearance requirements for cigarettes state that the surface of cigarettes should be clean and free of yellow spots longer than 2.0 mm. Among cigarette packaging and rolling quality defects, yellow-spotted defects belong to Category B, a more serious quality defect.

[0003] Yellow spots on cigarette surfaces are quite common, severely affecting their appearance and directly impacting the brand's image in the eyes of consumers. There are many causes of yellow spots during cigarette production, potentially occurring in multiple processes including tobacco processing, cigarette rolling, packaging, and storage. Based on their causes, yellow spots can generally be categorized as follows: **Material spots (mainly residues of auxiliary materials, resulting from uneven dispersion or excessive residue of sugars, flavorings, humectants, etc., added during the tobacco processing, which contaminate the cigarette paper); **Oil stains (mostly caused by leakage of lubricating oil or grease from production machinery during the cigarette rolling and packaging process, with a smaller portion caused by oxidation of tobacco leaf oils (such as nicotine and resin) or seepage from the tobacco at high temperatures, contaminating the cigarette paper); and **Water stains (mainly damp mold spots, caused by failure to dry damp cigarettes promptly, leading to mold growth or pigment decomposition (such as chlorophyll degradation) that contaminates the cigarette paper).**

[0004] Prevention and control of yellow-spotted smoke has always been a key focus of the tobacco industry. In recent years, numerous research papers and patents have been published on the identification of yellow-spotted contaminant types; however, existing techniques and experimental strategies for detecting yellow spots have the following shortcomings: Simply relying on peak matching and characteristic peak comparison methods based on infrared spectroscopy and mass spectrometry data is insufficient for reliably identifying the type of macula. For example, patent applications CN116952886A, "System and Method for Identifying the Source of Macula Smoke Pollutants Based on Infrared Absorption Spectroscopy," and CN112362608A, "Method for Identifying the Source of Flavor Smoke Pollution Based on Infrared Spectroscopy Technology," both disclose methods for identifying the source of macula smoke pollutants by comparing the peak values ​​of the infrared spectrum of the macula to be tested with those of historical macula smoke spectra, and by comparing them with the peak threshold values ​​of a control simulated macula spectrum. The infrared spectrum of the macula mainly exhibits five infrared absorption bands, located between 3700 and 3020 cm⁻¹. -1 3020-2800 cm-1 1800-1550 cm -1 1550-1200 cm -1 1200-950 cm -1 and 886-852 cm -1 However, within these five spectral bands, information about macular matter is usually implied only by relatively weak variations in the 3020-2800 cm⁻¹ range. -1 1800-1550 cm -1 and 1200-950 cm -1 In the middle, and significantly affected by tobacco paper substances; 1550-1200 cm -1 and 886-852 cm -1 It primarily reflects information about the functional groups of the tobacco paper, rarely containing information about the macular structure; while 3700-3020cm -1 The associated functional groups have complex origins and are difficult to quantify. Therefore, simply using the peak control method may reduce the reliability of identifying macular types and tracing the origins of macular substances. Summary of the Invention

[0005] To address the problem that existing methods for detecting yellow spots on cigarettes based on infrared spectral peaks have insufficient reliability due to weak yellow spot characteristic signals and strong interference from cigarette paper, this invention provides a method for rapidly identifying the type of yellow spots on cigarette surfaces using infrared spectroscopy.

[0006] This invention is achieved using the following techniques: A method for rapidly identifying the type of yellow spots on cigarette surfaces using infrared spectroscopy includes the following steps: a. Sample preparation aa, Preparation of macular samples In the cigarette paper of the yellow-stained cigarette, a sample of the yellow-stained cigarette paper is cut out along the outline of the yellow-stained area, 1 mm outward, with the yellow-stained area as the center. Specifically, the cigarette paper of the yellow-stained cigarette is cut longitudinally and the tobacco is peeled off. The tobacco residue attached to the inner surface of the cigarette paper is gently wiped away with degreased cotton or a brush. The yellow-stained cigarette paper is then cut out along the outline of the yellow-stained area, 1 mm outward, with clean, sharp scissors, as the yellow-stained sample.

[0007] ab, Preparation of spot-covered cigarette paper samples In the same batch of cigarettes, at least 5 cigarette paper samples without yellow spots are cut from the cigarette paper outside the yellow spot area, i.e., the area of ​​cigarette paper without yellow spots. The cigarette paper samples outside the yellow spot area are square or round samples with a side length or diameter of 4~6mm. The area of ​​the cigarette paper samples outside the yellow spot area meets the requirements of ATR-FTIR test and is used as the cigarette paper samples outside the yellow spot area, i.e., background cigarette paper.

[0008] Preparation of simulated pollution source spot samples (ac) The simulated pollution source samples include samples with liquid impregnation, samples with lubricant impregnation, and samples with tobacco impregnation.

[0009] The preparation of samples with liquid impregnation spots and lubricant impregnation spots includes the following steps: One or more of the following may be the source of yellow stains: liquids and lubricants. Samples of liquids used in cigarette production and lubricants used in cigarette machinery are taken. 0.5–2.0 μL or mg of the liquid or lubricant sample is drawn using a capillary tube, pipette tip, or fine glass rod, and then spotted onto unspotted cigarette paper. The liquid sample includes additives used in tobacco and stems, specifically sugars and flavorings. The lubricant sample includes lubricating oils and greases used in cigarette machinery. The unspotted cigarette paper is from the same batch as the yellow-spotted cigarette paper and the unspotted outer cigarette paper from step a, and is made by peeling from unspotted cigarette paper. Spotting and diffusion form 2–5 mm diameter impregnation spots, which are then stored for 12 hours at the same temperature and humidity as during cigarette production or storage. These are used as liquid impregnation spot samples and lubricant impregnation spot samples.

[0010] The humidified tobacco was pressed between two clean tobacco papers and stored for 12 hours. Specifically, tobacco from a cigarette was taken, laid flat on a stainless steel mesh, and placed in an ultrasonic atomization chamber for humidification with water mist for 1 hour. 0.2g of humidified tobacco was then placed between two flat blank tobacco papers with tweezers and pressed down with a 10g weight for 12 hours. The storage temperature and humidity were the same as those during cigarette production or storage, and this was used as a sample of tobacco immersion spots.

[0011] b. Measure the ATR-FTIR spectrum Using tweezers, the yellow spot sample and the outer cigarette paper sample were placed into the ATR component of the attenuated total reflectance infrared spectrometer (ATR-FTIR). If a pollution source simulated spot sample was prepared in step a, it was also tested. The ATR-FTIR spectral data of the yellow spot sample, the outer cigarette paper sample, and the pollution source simulated spot sample were collected, expressed as absorbance. That is, the ATR-FTIR spectrum is plotted with wavenumber on the x-axis and absorbance on the y-axis. The spectral data after removing the air background and baseline smoothing were used as the data for the yellow spot sample, the outer cigarette paper sample, and the pollution source simulated spot sample.

[0012] Based on the obtained ATR-FTIR spectral data, the characteristic index A value is calculated according to the following formula. A = I1 / I2; Where: A — peak area ratio; I1——3020-2800 cm -1 Peak area expressed as absorbance; I2——886-852 cm-1 The peak area expressed as absorbance.

[0013] For macular samples, the A value of a single macular sample or the average A value of multiple macular samples is calculated as the A value of a single macular sample or the A value of macular samples from the same batch. For samples of outer cigarette paper and samples of simulated pollution sources, the average A value of at least 5 samples is calculated as the A value of the outer cigarette paper and samples of simulated pollution sources.

[0014] c. Determine the type of macular degeneration The A-value of the yellow spot sample calculated in step b is compared with the A-value of the outer spot cigarette paper sample and the A-value of the pollution source simulated spot sample (if pollution source simulated spot samples of cigarette paper from the same batch of cigarettes were prepared, they are compared together) and then compared with the database. The database includes data of pollution source simulated spot samples, which are obtained by ATR-FTIR spectroscopy testing in step b, with the combined spectrum in the range of 1800-1550 cm⁻¹. -1 The characteristic peak morphology of the bands is used to assist in the determination, and the type of macula is determined based on the comparison results. Specifically, the A value of the macula sample is determined sequentially: If the A value of the macular sample is less than or equal to the A value of the outer cigarette paper sample, the output will be a weak signal that is difficult to judge. If the A value of the yellow stain sample is ≥ 0.8 × the A value of the lubricant-impregnated stain sample, it is judged as a suspected oil stain. If the A value of the yellow spot sample is ≥ 0.8 × the A value of the liquid-impregnated spot sample, it is judged as a suspected liquid-impregnated spot. If the A value of the yellow spot sample is ≥ 0.8 × the A value of the tobacco soaking spot sample, it is judged as a suspected tobacco soaking spot; When a yellow stain sample is identified as a suspected oil stain, liquid stain, or tobacco stain, the statistical information (A value and characteristic spectral peaks of each brand of cigarette and each type of yellow stain) from the yellow stain smoke infrared spectral database (which summarizes and records historical ATR-FTIR test data and identification results) is used to determine the conformity of the A value and to compare and identify the characteristic peaks. If they conform, the results are output and imported into the database; otherwise, an anomaly is reported.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention presents a method for rapidly identifying the types of yellow spots on cigarette surfaces using infrared spectroscopy. It utilizes attenuated total reflectance infrared spectroscopy (ATR-FTIR) to quickly identify lubricant-impregnated spots, liquid-impregnated spots, and tobacco-impregnated spots. A simulated control sample of the contamination source is prepared using unstained cigarette paper peeled from the same batch as the cigarettes being tested. This effectively eliminates the interference of inherent background contaminants in the cigarette paper on the detection data, significantly improving the reliability of the method. Furthermore, when using ATR-FTIR spectral data for substance identification, a new index (A-value) that can quantitatively characterize the overall spectral distribution is used. This is combined with the traditional characteristic peak comparison method for multidimensional analysis, thus providing a more comprehensive and reliable support for the derivation of the identification conclusions. Attached Figure Description

[0016] Figure 1 A flowchart illustrating the identification of macular types.

[0017] Figure 2 The images show representative ATR-FTIR spectra of the yellow spot 1# sample, yellow spot 2# sample, and the outer cigarette paper sample.

[0018] Figure 3 This shows a representative ATR-FTIR spectrum of a sample simulating a pollution source spot. Detailed Implementation

[0019] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] A method for rapidly identifying the type of yellow spots on cigarette surfaces using infrared spectroscopy, such as Figure 1 As shown, it includes the following steps: a. Sample preparation aa, Preparation of macular samples Take three cigarettes each from batch 1 and batch 2 with yellow spots, cut them lengthwise, and peel off the tobacco shreds. Gently wipe away the tobacco residue adhering to the inner surface of the cigarette paper with degreased cotton or a brush. Use clean, sharp scissors to cut off the cigarette paper with yellow spots along the outline of the yellow spot area, extending 1 mm outward. These are recorded as yellow spot sample 1 and yellow spot sample 2.

[0021] ab, Preparation of spot-covered cigarette paper samples In the same batch of cigarettes, square or round cigarette paper samples without yellow spots with a side length or diameter of 4-6 mm were cut from blank cigarette paper outside the yellow spot area and used as spotless cigarette paper samples; a total of 5 spotless cigarette paper samples were prepared.

[0022] Preparation of simulated pollution source spot samples (ac) One type of sugar and flavoring agent used in the production of cigarettes in the same batch were taken as liquid samples, and three types of lubricating oil and three types of lubricating grease used in cigarette machinery were taken as lubricant samples. Simulated stain samples of pollution sources were prepared respectively. Using a sampling capillary tube, 0.5–2.0 μL or mg of liquid sample and lubricant sample were respectively sampled and spotted onto cigarette paper (without yellow spots) peeled from the same batch of cigarettes. The spots were diffused to form impregnated spots with a diameter of 3–5 mm. Five simulated spots were prepared for each pollution source. The sampled samples were stored for 12 hours at the same temperature and humidity as during cigarette production or storage. The simulated spots were designated as sugar sample, flavoring sample, lubricant 1 sample, lubricant 2 sample, lubricant 3 sample, grease 1 sample, grease 2 sample, and grease 3 sample, respectively. Figure 3 The Chinese abbreviations are sugar, flavoring agent, oil 1, oil 2, oil 3, lipid 1, lipid 2, and lipid 3.

[0023] b. Measure the ATR-FTIR spectrum Attenuated total reflectance infrared spectroscopy (ATR-IR) was performed using a The Nicolet iN10 infrared spectrometer (Thermo Fisher Scientific, USA). Before each test, the surface of the Ge crystal in the ATR component was cleaned with anhydrous ethanol and dried with clean nitrogen gas or allowed to air dry. Samples with yellow spots 1#, 2#, the outer tobacco paper sample, and the simulated contaminant spot sample were placed in the ATR component using tweezers, ensuring that the outer side of the spot's central region (i.e., the side of the tobacco paper not in contact with the tobacco) was in close contact with the Ge crystal. The spectral scanning range was 4000–650 cm⁻¹. -1 4 cm resolution -1 The scan was performed 32 times, with air as the blank background. Figure 2 , 3 As shown, the collected spectral data were processed by removing the air background and using OMNIC 8.2 software. The ATR-FTIR spectrum was plotted with wavenumber on the x-axis and absorbance on the y-axis, and baseline smoothing was performed appropriately.

[0024] Based on the obtained ATR-FTIR data, the characteristic index A value of the yellow spot 1# sample, yellow spot 2# sample, outer cigarette paper sample, and pollutant simulated spot sample was calculated according to the following formula. A = I1 / I2; Where: A — peak area ratio; I1——3020-2800 cm -1 Peak area expressed as absorbance; I2——886-852 cm -1 The peak area expressed as absorbance.

[0025] The calculated A values ​​for each sample are shown in Tables 1 and 2.

[0026]

[0027] c. Determine the type of macular degeneration Based on the data in Tables 1 and 2, the A value of sample #1 of yellow spot is ≥ 0.8 × the A value of sample of lubricant impregnation, and it is judged to be a suspected oil stain. If the A value of the yellow stain sample is ≥0.8 × the A value of the liquid-impregnated stain sample, it is judged as a suspected liquid-impregnated stain. By combining the yellow spot smoke infrared spectral database, which summarizes and records the statistical information of historical ATR-FTIR test data and identification results, including the A value and characteristic spectral peaks of various brands of cigarettes and various types of yellow spots, the conformity of the A value of the yellow spot samples is judged, and the characteristic peaks are compared and identified. If they are consistent, the output result is that yellow spot 1# is an oil stain and yellow spot 2# is a liquid immersion stain, and the results are entered into the database.

[0028] The scope of protection claimed by this invention is not limited to the specific embodiments described above. Moreover, for those skilled in the art, this invention can have various modifications and alterations. Any modifications, improvements, and equivalent substitutions made within the concept and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for rapidly identifying the type of yellow spots on the surface of cigarettes using infrared spectroscopy, characterized in that: Includes the following steps: a. Sample preparation A sample of the yellow-stained cigarette paper was cut from the cigarette paper of the yellow-stained cigarette and used as the yellow-stained sample. In the same batch of cigarettes, at least 5 cigarette paper samples without yellow spots were cut from the cigarette paper outside the yellow spot area and without yellow spots, as the unspotted cigarette paper samples; b. Measure the ATR-FTIR spectrum The macular sample and the outer cigarette paper sample were placed in the ATR component of the attenuated total reflectance infrared spectrometer, and the ATR-FTIR spectral data of the samples expressed in terms of absorbance were collected. The spectral data after removing the air background and baseline smoothing were used as the data of the macular sample and the outer cigarette paper sample. Based on the obtained ATR-FTIR spectral data, the characteristic index A value is calculated according to the following formula. A = I1 / I2; Where: A — peak area ratio; I1——3020-2800 cm -1 Peak area expressed as absorbance; I2——886-852 cm -1 Peak area expressed as absorbance; c. Determine the type of macular degeneration The A value of the yellow macular sample calculated in step c was compared with the A value of the outer cigarette paper sample and the database, taking into account the spectral range of 1800-1550 cm⁻¹. -1 The characteristic peak morphology of the band is used to assist in the determination, and the type of macular is determined based on the comparison results.

2. The method for rapidly identifying the type of yellow spots on the surface of cigarettes using infrared spectroscopy according to claim 1, characterized in that: In step c, the database includes data on simulated pollution source spots. The data on simulated pollution source spots are obtained by ATR-FTIR spectroscopy. The simulated pollution source spots include samples of liquid impregnation, samples of lubricant impregnation, and samples of tobacco impregnation.

3. The method for rapidly identifying the type of yellow spots on the surface of cigarettes using infrared spectroscopy according to claim 2, characterized in that: The preparation of the liquid impregnation spot sample and the lubricant impregnation spot sample includes the following steps: Take samples of the liquid used in the cigarette production process and the lubricant used in cigarette machinery. Spot the liquid and lubricant samples onto cigarette paper without yellow spots. The cigarette paper without yellow spots is from the same batch as the cigarette paper with yellow spots and the cigarette paper outside the spots in step a. The spotting spreads to form impregnation spots with a diameter of 2-5 mm. Store for 12 hours to obtain the liquid impregnation spot samples and lubricant impregnation spot samples. The preparation of tobacco shred impregnation samples includes the following steps: Humidified tobacco shreds were pressed between two clean tobacco papers and stored for 12 hours to obtain tobacco shred impregnation samples.

4. The method for rapidly identifying the type of yellow spots on the surface of cigarettes using infrared spectroscopy according to claim 3, characterized in that: In step c, the A value of the macular sample is determined sequentially: If the A value of the macular sample is less than or equal to the A value of the outer cigarette paper sample, the output will be a weak signal that is difficult to judge. If the A value of the yellow stain sample is ≥ 0.8 × the A value of the lubricant-impregnated stain sample, it is judged as a suspected oil stain. If the A value of the yellow spot sample is ≥ 0.8 × the A value of the liquid-impregnated spot sample, it is judged as a suspected liquid-impregnated spot. If the A value of the yellow spot sample is ≥ 0.8 × the A value of the tobacco soaking spot sample, it is judged as a suspected tobacco soaking spot; When a yellow spot sample is identified as a suspected oil stain, liquid immersion stain, or tobacco immersion stain, the A value is judged based on the statistical information of the yellow spot smoke infrared spectroscopy database, and the characteristic peaks are compared and identified. If they are consistent, the results are output and imported into the database; otherwise, an anomaly is reported.

5. The method for rapidly identifying the type of yellow spots on the surface of cigarettes using infrared spectroscopy according to claim 1, characterized in that: Step a specifically includes the following steps: Cut the cigarette paper of the yellow-stained cigarette lengthwise and peel off the tobacco. Gently wipe away any tobacco residue adhering to the inner surface of the cigarette paper with absorbent cotton or a brush. Use clean, sharp scissors to cut off the cigarette paper with the yellow spots along the outline of the yellow spot area, extending 1 mm beyond the boundary. Record this as the yellow spot sample.

6. The method for rapidly identifying the type of yellow spots on the surface of cigarettes using infrared spectroscopy according to claim 1, characterized in that: In step a, the mottled cigarette paper sample is a square or round sample with a side length or diameter of 4-6 mm.

7. The method for rapidly identifying the type of yellow spots on the surface of cigarettes using infrared spectroscopy according to claim 3, characterized in that: The liquid sample includes additives used in tobacco shreds and stems; the lubricant sample includes lubricating oil and grease samples used in cigarette making machinery.

8. The method for rapidly identifying the type of yellow spots on the surface of cigarettes using infrared spectroscopy according to claim 3, characterized in that: In the sampling step, use a capillary tube, pipette tip, or fine glass rod to pick up 0.5~2.0μL or mg of liquid sample or lubricant sample; During the storage process, the temperature and humidity are the same as those used during cigarette production or storage. In the preparation of tobacco shred impregnation spot samples, a 10g weight was used for pressing.

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