Method for obtaining content of inorganic elements in tobacco or tobacco products

Abstract

The invention provides a method for obtaining the content of inorganic elements in tobacco or a tobacco product. The method comprises the following steps: obtaining a sample of the tobacco or the tobacco product; obtaining the content of to-be-detected inorganic elements in the sample through a chemical analysis method; collecting a near infrared spectrum of the sample; establishing a prediction model based on the content of the inorganic elements to be detected in the sample and the near infrared spectrum of the sample; obtaining a near infrared spectrum of the to-be-detected tobacco or tobacco product; based on the near infrared spectrum of the to-be-detected tobacco or tobacco product and the prediction model, the content of the to-be-detected inorganic elements in the to-be-detected tobacco or tobacco product is obtained. According to the method provided by the invention, after the prediction model is established through the content of the to-be-detected inorganic elements in the sample and the near infrared spectrum of the sample, the content of the inorganic elements in the to-be-detected tobacco or tobacco product is directly predicted based on the near infrared spectrum of the to-be-detected tobacco or tobacco product and the prediction model; therefore, the content of the inorganic elements in the to-be-detected tobacco or tobacco product can be rapidly obtained.

Description

Technical Field

[0001] The present application relates to the technical field of tobacco, and in particular to a method for obtaining the content of inorganic elements in tobacco or tobacco products. Background Art

[0002] The content of inorganic elements in tobacco has an important impact on its quality and combustion characteristics. For example, the content of potassium, magnesium, calcium and other elements in tobacco not only affects the taste and aroma of tobacco, but is also closely related to the content of harmful substances produced by its combustion. Therefore, accurate determination of the content of these inorganic elements in tobacco is of great significance for tobacco quality control and formulation optimization.

[0003] At present, the main detection methods for inorganic elements (such as potassium, calcium, magnesium, etc.) in tobacco and tobacco products include ion chromatography, continuous flow method, microwave digestion-inductively coupled plasma mass spectrometry, etc. With the development of the digital transformation of cigarette products in the tobacco industry, it is necessary to obtain a large amount of chemical composition information efficiently and conveniently. However, these methods are relatively complex to operate and have slow detection speed, which is not conducive to batch detection. Summary of the invention

[0004] To at least partially solve the above-mentioned problems, an embodiment of the present application provides a method for obtaining the content of inorganic elements in tobacco or tobacco products, the method comprising: obtaining a sample of tobacco or tobacco products; obtaining the content of the inorganic element to be tested in the sample by chemical analysis; collecting a near-infrared spectrum of the sample; establishing a prediction model based on the content of the inorganic element to be tested in the sample and the near-infrared spectrum of the sample; obtaining the near-infrared spectrum of the tobacco or tobacco product to be tested; and obtaining the content of the inorganic element to be tested in the tobacco or tobacco product to be tested based on the near-infrared spectrum of the tobacco or tobacco product to be tested and the prediction model.

[0005] In some embodiments, after collecting the near-infrared spectrum of the sample, the method further includes: using multi-far scattering correction, first-order derivative, and SG smoothing algorithm to process the near-infrared spectrum and eliminate abnormal data.

[0006] In some embodiments, before collecting the near-infrared spectrum of the sample, the method further includes: performing a balancing treatment on the water content of the sample so that the water content of the sample is maintained at 6% to 8%.

[0007] In some embodiments, the moisture of the sample is balanced, including placing the sample in a constant temperature and humidity environment with a temperature of 22±2° C. and a humidity of 35±5%, and performing the balance treatment for 48±0.5 hours.

[0008] In some embodiments, the conditions for collecting the near infrared spectrum of the sample are: the ambient temperature is 15°C to 28°C, the relative humidity is 30% to 50%, and the near infrared spectrum scanning range is 10000 to 4000 cm -1, resolution 8cm -1 , scan 64±1 times, and take the average of the two spectral results.

[0009] In some embodiments, a prediction model is established based on the content of the inorganic element to be measured in the sample and the near-infrared spectrum of the sample, including: constructing a chemometric relationship between near-infrared spectral data and the content of the inorganic element to be measured through one or more of multiple linear regression, principal component regression, partial least squares regression, support vector regression, and artificial neural network method to obtain a prediction model.

[0010] In some embodiments, the samples include first-cured tobacco leaves / re-cured tobacco strips samples, aged tobacco strips samples and cigarette tobacco shreds samples, and establishing the prediction model further includes: establishing prediction models for first-cured tobacco leaves / re-cured tobacco strips samples, aged tobacco strips samples and cigarette tobacco shreds samples respectively.

[0011] In some embodiments, obtaining a sample of tobacco or tobacco products includes: placing the tobacco or tobacco products in an oven, drying the tobacco or tobacco products at a temperature below 40°C, and then grinding the dried tobacco or tobacco products into powder with a particle size of less than or equal to 60 mesh using an ultracentrifugal grinder, mixing and then collecting, sealing, and affixing a unique identification to obtain the sample.

[0012] In some embodiments, the content of the inorganic element to be measured in the sample is obtained by chemical analysis, including: obtaining the content of the inorganic element to be measured in the sample by one of ion chromatography, continuous flow method, and microwave digestion-inductively coupled plasma mass spectrometry.

[0013] In some embodiments, the inorganic elements to be detected include one or more of potassium, calcium, and magnesium.

[0014] The method for obtaining the content of inorganic elements in tobacco or tobacco products provided in the embodiments of the present application is to establish a prediction model through the content of the inorganic element to be tested in the sample and the near-infrared spectrum of the sample, and then directly predict the content of inorganic elements in the tobacco or tobacco products to be tested based on the near-infrared spectrum of the tobacco or tobacco products to be tested and the prediction model, thereby quickly obtaining the content of inorganic elements in the tobacco or tobacco products to be tested. Since near-infrared spectroscopy technology has the advantages of being fast and accurate, the method provided in the embodiments of the present application can quickly and accurately obtain the content of inorganic elements in tobacco or tobacco products. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 is a flow chart of a method for obtaining the content of inorganic elements in tobacco or tobacco products provided by an embodiment of the present application;

[0017] Figure 2 It is a scatter plot of predicted values ​​and measured values ​​obtained when verifying the accuracy of the prediction model provided by an embodiment of the present application. DETAILED DESCRIPTION

[0018] The technical scheme of the preferred embodiment of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection claimed in the present application.

[0019] Near-infrared spectroscopy (NIR) technology has the advantages of being non-destructive, rapid and accurate. The inventors of the present application have found that with the continuous development of near-infrared spectroscopy technology and multi-target, high-throughput, and highly sensitive analytical techniques, large amounts of multidimensional, information-rich data collection have become possible. Therefore, with the help of near-infrared technology, by obtaining the chemical composition data of the classical chemical analysis method of representative samples and the near-infrared spectroscopy data, the chemometric relationship between the two data is studied, and the prediction model and the model prediction effect evaluation parameters are obtained, which can realize the rapid determination of inorganic elements such as potassium, calcium, magnesium, etc. in tobacco and tobacco products, and provide technical support for product quality control and cigarette product design. The method provided by the present invention is simple, efficient, accurate, and reliable.

[0020] Combination Figure 1, the embodiment of the present application provides a method for obtaining the content of inorganic elements in tobacco or tobacco products, the method comprising: obtaining a sample of tobacco or tobacco products; obtaining the content of the inorganic elements to be measured in the sample by chemical analysis; collecting the near-infrared spectrum of the sample; establishing a prediction model based on the content of the inorganic elements to be measured in the sample and the near-infrared spectrum of the sample; obtaining the near-infrared spectrum of the tobacco or tobacco products to be measured; obtaining the content of the inorganic elements to be measured in the tobacco or tobacco products to be measured based on the near-infrared spectrum of the tobacco or tobacco products to be measured and the prediction model. In this embodiment, the tobacco or tobacco products to be measured and the sample of tobacco or tobacco products are the same tobacco or tobacco products, and a prediction model is established by analyzing and detecting the sample, and then the inorganic elements to be measured are predicted for the tobacco or tobacco products to be measured by the prediction model. In some embodiments, the inorganic elements to be measured include one or more of potassium, calcium, and magnesium. For example, the inorganic elements to be measured may include potassium, calcium, and magnesium.

[0021] The method for obtaining the content of inorganic elements in tobacco or tobacco products provided in the embodiments of the present application is to establish a prediction model through the content of the inorganic element to be tested in the sample and the near-infrared spectrum of the sample, and then directly predict the content of inorganic elements in the tobacco or tobacco products to be tested based on the near-infrared spectrum of the tobacco or tobacco products to be tested and the prediction model, thereby quickly obtaining the content of inorganic elements in the tobacco or tobacco products to be tested. Since near-infrared spectroscopy technology has the advantages of being fast and accurate, the method provided in the embodiments of the present application can quickly and accurately obtain the content of inorganic elements in tobacco or tobacco products.

[0022] In some embodiments, after collecting the near-infrared spectrum of the sample, it also includes: using multi-scattering correction, first-order derivative, and SG smoothing algorithm to process the near-infrared spectrum and remove abnormal data. In this embodiment, multivariate scattering correction (MSC), first-order derivative, and SG smoothing are used to pre-process the near-infrared spectrum to obtain a representative sample of 8000-4000cm -1 The near infrared spectral feature information of the spectral interval can be cross-validated to eliminate abnormal samples. In this embodiment, the accuracy of the prediction model is improved by optimizing the selection of the spectral wavelength range through multiple algorithms and their combination.

[0023] In some embodiments, before collecting the near-infrared spectrum of the sample, it also includes: balancing the moisture of the sample so that the moisture of the sample is maintained at 6% to 8%. In this embodiment, by balancing the sample and keeping the moisture between 6% and 8%, the influence of moisture during near-infrared spectrum collection can be reduced. In some embodiments, balancing the moisture of the sample includes: placing the sample in a constant temperature and humidity environment with a temperature of 22±2°C and a humidity of 35±5%, and balancing for 48±0.5 hours. In this embodiment, the moisture content is controlled by the above-mentioned conditional balancing.

[0024] In some embodiments, the conditions for collecting the near infrared spectrum of the sample are: the ambient temperature is 15°C to 28°C, the relative humidity is 30% to 50%, and the near infrared spectrum scanning range is 10000 to 4000 cm -1 , resolution 8cm -1 , scan 64±1 times (preferably 64 times), and take the average of the two spectral results. In this embodiment, the near-infrared spectrometer can be a Fourier transform type, and the above acquisition conditions can obtain a more accurate near-infrared spectrum.

[0025] In some embodiments, based on the content of the inorganic element to be measured in the sample and the near infrared spectrum of the sample, a prediction model is established, including: constructing a chemometric relationship between the near infrared spectrum data and the content of the inorganic element to be measured by one or more of multiple linear regression (MLR), principal component regression (PCR), partial least squares regression (PLS), support vector regression (SVR), and artificial neural network methods to obtain a prediction model. Preferably, a chemometric relationship between the near infrared spectrum data and the content of the inorganic element to be measured can be constructed by partial least squares regression (PLS) to obtain a prediction model. In some embodiments, the sample includes a first-cured tobacco leaf / re-cured tobacco strip sample, an alcoholized tobacco strip sample, and a cigarette tobacco shred sample, and establishing the prediction model also includes: establishing prediction models for the first-cured tobacco leaf / re-cured tobacco strip sample, the alcoholized tobacco strip sample, and the cigarette tobacco shred sample, respectively. In this embodiment, the above samples cover various application scenarios, turning the complete tobacco chemical composition data chain from pre-cured tobacco to cigarette products from possibility into reality, and the three samples are highly representative, basically covering tobacco leaf samples from major producing areas across the country and cigarette samples from various industrial companies, thereby improving the accuracy and applicability of the model.

[0026] For example, a near infrared quantitative prediction model for potassium, calcium and magnesium in first-cured tobacco leaves / re-cured strips, aged strips and cigarette cut tobacco can be established, as shown in Table 1. 2 As indicators for evaluating the quality of the model, it can be seen that good prediction models have been established for the three components of potassium, calcium and magnesium.

[0027] Table 1

[0028]

[0029] The established prediction model can be used to predict the potassium, calcium, and magnesium content in the tobacco or tobacco products to be tested, and the accuracy and reliability of the model can be verified by comparing with the actual measured values. 20 aged tobacco leaf samples were taken to verify the prediction model, and the results showed that the measured values ​​obtained by the classical chemical analysis method were basically consistent with the results of the prediction model. Taking potassium as an example, the scatter plot of its predicted value and measured value is shown in Figure 2 .

[0030] In some embodiments, obtaining a sample of tobacco or tobacco products includes: placing tobacco or tobacco products in an oven, drying tobacco or tobacco products at a temperature below 40°C, and then crushing the dried tobacco or tobacco products into powders with a particle size of less than or equal to 60 meshes by an ultracentrifugal grinder, collecting and sealing after mixing, and affixing a unique identification to obtain a sample. In this embodiment, the sample is pre-treated by ultracentrifugal grinding, crushing and filtering are integrated, and the temperature is kept at room temperature during the crushing process, avoiding the problem of intermittent grinding due to temperature rise in conventional treatment methods such as pulverizers. Exemplarily, the tobacco or tobacco products are dried and crushed at low temperature (not exceeding 40°C), and then the sample is finely crushed using an ultracentrifugal grinder that integrates crushing and filtering to obtain tobacco powder. Tobacco or tobacco products can be 361 first-baked tobacco leaves / re-baked tobacco leaves from different production areas and different parts produced in 2021, alcoholized tobacco leaves are alcoholized tobacco leaves in the warehouse of 298 companies, and cigarette tobacco shreds are produced by 286 industrial enterprises. The instrument parameters of the ultracentrifugal grinder may be: the number of revolutions is 15000 revolutions per minute, and the sieve aperture is 0.25 mm.

[0031] In some embodiments, the content of the inorganic element to be measured in the sample is obtained by chemical analysis, including: obtaining the content of the inorganic element to be measured in the sample by one of ion chromatography, continuous flow method, and microwave digestion-inductively coupled plasma mass spectrometry.

[0032] Preferably, the content of the inorganic element to be measured in the sample can be obtained by microwave digestion-inductively coupled plasma mass spectrometry. Exemplarily, 0.2g of sample mixed in advance can be accurately weighed, placed in a microwave digestion tank, 5mL nitric acid and 1mL hydrogen peroxide are added, the sealed back is placed in a microwave digestion instrument, the sample is digested according to the microwave digestion program provided, the solution should be clear and transparent after the digestion process is completed, and then the sample solution is transferred to a plastic 50mL volumetric flask, the digestion tank is rinsed with ultrapure water 3-4 times, and constant volume, and the sample solution is obtained after shaking up. Draw sample blank solution respectively, sample solution and internal standard solution are injected into inductively coupled plasma mass spectrometry, under selected instrument parameters, the ratio of the mass-to-charge ratio intensity of the element potassium, calcium and magnesium to be measured and the mass-to-charge ratio intensity of the corresponding internal standard element is substituted into the regression equation made by the standard working solution, and potassium, calcium and magnesium concentrations in the sample blank solution and the sample solution are obtained, and the content of potassium, calcium and magnesium in the sample is obtained by metering. The limits of quantification of potassium, calcium and magnesium were between 0.006 and 0.009 mg / g, the repeatability was between 2.35 and 3.18%, and the recoveries of spiked samples were between 98.5 and 102.5.

[0033] The method provided in the embodiments of the present application solves the problem that the existing determination methods of potassium, calcium and magnesium in tobacco and tobacco products are complicated in operation and have a long cycle. It has the advantages of being accurate and reliable, simple and easy to operate, convenient and fast, safe and environmentally friendly. It is particularly suitable for the detection of batch samples and can provide simple and fast technical support for tobacco leaf procurement, quality evaluation and product development.

[0034] Example

[0035] Materials, reagents and instruments:

[0036] The samples are 361 first-cured tobacco leaves / re-cured strips from different production areas and parts produced in 2021, 298 companies' alcoholized strips in stock, and 286 industrial enterprises producing cigarette tobacco. Ultrapure water (resistivity ≥ 18.2MΩ·cm), which should meet the requirements of first-class water in GB / T6682; nitric acid (65%, mass fraction), hydrogen peroxide (30%, mass fraction) (Merck, USA); potassium, calcium, and magnesium (concentrations are all 1000ug / mL, national standard substances);

[0037] Mars6 microwave digester (CEM, USA); NexION350D inductively coupled plasma mass spectrometer (PE, USA); MPA Fourier transform near-infrared spectrometer (Bruker, Germany); AB204-E electronic analytical balance (Mettler-Toledo Instruments (Shanghai) Co., Ltd.); Milli-Q direct16 ultrapure water machine (Merck Millipore, France); ZM300 ultracentrifugal grinder (Retsch, Germany).

[0038] method:

[0039] 1. Sample preparation: Place the test sample in an oven and dry it at a temperature below 40°C. Then, use an ultracentrifugal grinder to grind the dried sample into a powder with a particle size of ≤60 mesh at a speed of 15,000 rpm and a sieve aperture of 0.25 mm. Mix well and put it into a sample bag, seal it, and affix a unique label. Before testing the sample, place it in a constant temperature and humidity environment with a temperature of 22±2°C and a humidity of 35±5%. After balancing for 48 hours, prepare the sample with a moisture content of 6-8% for testing.

[0040] 2. Spectrum acquisition: Near infrared spectrum acquisition conditions: ambient temperature is 15℃~28℃, relative humidity is 30%~50%, near infrared spectrum scanning range is 10000~4000cm -1 , resolution 8cm -1 , scan 64 times and take the average of the two spectral results.

[0041] 3. Microwave digestion-ICP-MS determination of potassium, calcium and magnesium:

[0042] (1) Sample pretreatment: Accurately weigh 0.2 g (accurate to 0.0001 g) of the pre-mixed sample, place it in a microwave digestion tank, add 5 mL of 65% nitric acid and 1 mL of 30% hydrogen peroxide in sequence, tighten the seal and place it in a microwave digester. Digest the sample according to the microwave digestion program set in Table 2. The solution should be clear and transparent after the digestion process is completed. Transfer the sample solution to a 50 mL plastic volumetric flask, rinse the digestion tank with ultrapure water 3 to 4 times, transfer the cleaning solution to the volumetric flask, then make up to volume with ultrapure water, and shake well to obtain the sample solution. Prepare the reagent blank solution in the same way. Table 2 is an exemplary microwave digestion heating program.

[0043] Table 2

[0044]

[0045] (2) Inductively coupled plasma mass spectrometer (ICP-MS) parameters: The mass number of the element to be measured, the corresponding internal standard element and the integration time are shown in Table 3.

[0046] Table 3

[0047]

[0048] The instrument was debugged with 10 μg / L tuning solution to set the inductively coupled plasma mass spectrometer to the best working environment. The instrument parameters are shown in Table 4. The samples after volume adjustment were measured by inductively coupled plasma mass spectrometry. The isotopes with higher abundance and less interference of K, Ca and Mg elements were selected as the measurement objects, corresponding to 39 K. 44 Ca and24 Mg. Also select 45 Sc is the internal standard. The internal standard method is used for quantification, with the ratio of the concentration of the elements potassium, calcium and magnesium to the corresponding internal standard concentration as the horizontal coordinate, and the ratio of the mass-to-charge intensity of the elements potassium, calcium and magnesium to the corresponding internal standard element mass-to-charge intensity as the vertical coordinate, to establish the standard working curves of potassium, calcium and magnesium, and then calculate the content of potassium, calcium and magnesium in the sample.

[0049] Table 4

[0050]

[0051] result:

[0052] 1. Evaluation of classical chemical analysis methods for potassium, calcium and magnesium: The detection limits, repeatability and recovery rates of microwave digestion-ICP-MS for the determination of potassium, calcium and magnesium in tobacco and tobacco products were investigated. The results are shown in Table 5.

[0053] As can be seen from Table 5, the limits of quantification of potassium, calcium and magnesium are between 0.006 and 0.009 mg / g, the repeatability is between 2.35 and 3.18%, and the spike recovery is between 98.5 and 102.5. This shows that the method has a low detection limit, high recovery rate and good repeatability, and can be used for the determination of potassium, calcium and magnesium.

[0054] Table 5

[0055]

[0056] 2. Full spectrum band preprocessing and outlier removal: Multivariate scatter correction (MSC), first-order derivative, and SG smoothing are used to preprocess the near-infrared spectrum to obtain representative samples from 8000 to 4000 cm -1 The near-infrared spectral feature information of the spectral range is obtained, and the cross-validation method is used to eliminate abnormal samples.

[0057] 3. Establishment and evaluation of quantitative analysis model: After preprocessing the spectrum, the partial least squares (PLS) method was used to construct the chemometric relationship between near-infrared spectral data and chemical composition data, and near-infrared quantitative prediction models of potassium, calcium and magnesium in first-cured tobacco leaves / re-cured strips, aged strips and cigarette tobacco were established, as shown in Table 1. The determination coefficient R2 was used as an indicator to evaluate the quality of the model. Good prediction models were established for the three components of potassium, calcium and magnesium, and the model evaluation parameters were generally satisfactory.

[0058] 20 aged tobacco samples were used to verify the infrared quantitative prediction model. The results showed that the measured values ​​obtained by the classical chemical analysis method were basically consistent with the results of the prediction model. Taking potassium as an example, the scatter plot of its predicted value and measured value is shown in Figure 2 .

[0059] 4. Comparison of chemical analysis method with the method provided in the examples of this application:

[0060] (1) Comparison of the precision of the two methods: The relationship between the precision of the microwave digestion-ICP-MS determination method and the precision of the constructed near-infrared prediction method was investigated. The results are shown in Table 6. It can be seen that the precision difference between the two methods is very small.

[0061] Table 6

[0062]

[0063] (2) Comparison of the efficiency of the two methods: When the microwave digestion-ICP-MS determination method is used to obtain the potassium, calcium, and magnesium contents of the sample, it takes a long time due to the numerous steps. However, when the potassium, calcium, and magnesium contents are predicted by combining the constructed prediction model with near-infrared spectroscopy, it is only necessary to obtain the infrared spectrum of the sample to be tested, and then the prediction model can quickly predict the results in a short time.

[0064] Based on the above-mentioned embodiments of the present application, in the absence of explicit negation or conflict, the technical features of one embodiment may be beneficially combined with one or more other embodiments.

[0065] Although some specific embodiments of the present application have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are only for illustration and not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A method for obtaining the content of inorganic elements in tobacco or tobacco products, characterized in that: include: obtaining a sample of the tobacco or the tobacco product; Obtaining the content of the inorganic element to be measured in the sample by chemical analysis; collecting a near infrared spectrum of the sample; Establishing a prediction model based on the content of the inorganic element to be measured in the sample and the near infrared spectrum of the sample; Obtaining a near infrared spectrum of the tobacco or tobacco product to be tested; Based on the near infrared spectrum of the tobacco or tobacco product to be tested and the prediction model, the content of the inorganic element to be tested in the tobacco or tobacco product to be tested is obtained.

2. The method according to claim 1, characterized in that After collecting the near infrared spectrum of the sample, the method further comprises: The near infrared spectrum is processed by multi-far scattering correction, first-order derivative and SG smoothing algorithm, and abnormal data are eliminated.

3. The method according to claim 1, characterized in that Before collecting the near infrared spectrum of the sample, the method further comprises: The moisture content of the sample is balanced so that the moisture content of the sample is maintained at 6% to 8%.

4. The method according to claim 3, characterized in that The sample is subjected to a moisture balance treatment, comprising: The sample is placed in a constant temperature and humidity environment with a temperature of 22±2° C. and a humidity of 35±5% for 48±0.5 hours of equilibrium treatment.

5. The method according to claim 1, characterized in that The conditions for collecting the near infrared spectrum of the sample are as follows: the ambient temperature is 15°C to 28°C, the relative humidity is 30% to 50%, and the near infrared spectrum scanning range is 10000 to 4000 cm -1 , resolution 8cm -1 , scan 64±1 times, and take the average of the two spectral results.

6. The method according to claim 1, characterized in that Based on the content of the inorganic element to be measured in the sample and the near infrared spectrum of the sample, a prediction model is established, comprising: The prediction model is obtained by constructing a chemometric relationship between near-infrared spectral data and the content of the inorganic element to be measured through one or more of multiple linear regression, principal component regression, partial least squares regression, support vector regression, and artificial neural network methods.

7. The method according to claim 6, characterized in that The samples include first-cured tobacco leaves / re-cured tobacco strips samples, aged tobacco strips samples and cigarette tobacco cut samples, and establishing a prediction model further includes: Prediction models are established for the first-cured tobacco leaves / re-cured tobacco strip samples, the aged tobacco strip samples and the cigarette tobacco shred samples respectively.

8. The method according to claim 1, characterized in that Obtaining a sample of the tobacco or the tobacco product, comprising: The tobacco or tobacco product is placed in an oven, dried at a temperature below 40° C., and then ground into powder with a particle size of 60 mesh or less by an ultracentrifugal grinder. After mixing, the powder is collected, sealed, and a unique identification is affixed to obtain the sample.

9. The method according to claim 1, characterized in that: The content of the inorganic element to be measured in the sample is obtained by chemical analysis, including: The content of the inorganic element to be measured in the sample is obtained by one of ion chromatography, continuous flow method and microwave digestion-inductively coupled plasma mass spectrometry.

10. The method according to claim 1, characterized in that The inorganic elements to be detected include one or more of potassium, calcium and magnesium.

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