Method for determining odor threshold value of odor substance of artificial board

Abstract

The invention relates to a method for determining an odor threshold value of an odor substance of an artificial board, belongs to the technical field of odor detection of the artificial board, and solves the problem that the result accuracy of an odor analysis system is influenced due to low detection precision of the odor threshold value of the odor substance of the artificial board in the prior art. The method comprises the following steps: preparing a sample; the method comprises the following steps: pretreating a test sample, and collecting mixed odor substances in the test sample; separating the mixed odor substances by using gas chromatography, and respectively conveying the separated single odor substances to a mass spectrum for qualitative analysis of the odor substances; the method comprises the following steps: carrying out qualitative analysis on the odorous substances, conveying the odorous substances to a sniffing instrument by using carrier gas for artificial sniffing, adjusting a split ratio at a sample inlet, and determining a sniffing threshold value of each odorous substance. The detection precision of the odor threshold value of the odor substances of the artificial board is improved.

Description

Technical Field

[0001] The invention relates to the technical field of odor detection of artificial boards, and in particular to a method for determining the odor threshold of odor substances in artificial boards. Background Art

[0002] Artificial boards are widely used in interior decoration and furniture production due to their excellent physical and mechanical properties and price advantages, and have become the main wooden raw materials in the custom home furnishing industry. However, with the extensive use of wooden home furnishing materials indoors, the volatile organic compounds (VOCs) and odors they produce have an increasingly greater impact on people. In order to solve the odor problem of artificial boards, it is necessary to determine the source of odor substances in artificial boards from the production materials and production process of artificial boards, and establish a suitable analysis method for odor substances in artificial boards.

[0003] At present, both at home and abroad, corresponding testing standards have been formulated for the odor characteristics of adhesives, leather, packaging materials, building materials and indoor air in terms of odor intensity, odor concentration and odor threshold. Among them, the odor threshold of odor substances in artificial boards refers to the minimum olfactory detection mass concentration of various odor substances emitted by artificial boards, and the unit is mg / m 3 , the odor threshold is the olfactory threshold. The odor threshold is used to evaluate the odor activity value, and the odor activity value is used to evaluate the strength of the odor, laying the foundation for the establishment of an odor analysis system, providing data support, and then screening suitable wood raw materials and other auxiliary materials for the production of low-odor wooden home materials, determining the treatment object of the odor of artificial boards, and providing a treatment basis for solving the odor problem of artificial boards.

[0004] At present, the dynamic dilution method combined with artificial sniffing is generally used to determine the odor threshold. However, for odor substances with a boiling point higher than 100°C, some odor substances will condense and deposit when determining the odor threshold, causing the detected odor threshold to be higher than the actual value, thereby affecting the judgment of the odor substances in the board and the accuracy of the odor analysis system results. Summary of the invention

[0005] In view of the above analysis, an embodiment of the present invention aims to provide a method for determining the olfactory threshold of odor substances in artificial boards, so as to solve the problem that the existing olfactory threshold detection accuracy of odor substances in artificial boards is low, which affects the accuracy of the results of the odor analysis system.

[0006] On the one hand, an embodiment of the present invention provides a method for determining the olfactory threshold of odor substances in artificial boards, comprising:

[0007] Step 1: Prepare test sample;

[0008] Step 2: Pre-treat the test sample and collect the mixed odor substances in the test sample;

[0009] Step 3: Separate the mixed odor substances by gas chromatography, and send the separated single odor substances to the mass spectrometer for qualitative analysis of the odor substances;

[0010] Step 4: While completing the qualitative analysis of the odor substance, use carrier gas to transport the odor substance to the olfactometer for artificial olfaction, adjust the split ratio at the injection port, and measure the olfactory threshold of each odor substance.

[0011] Furthermore, in step 2, the test sample is pre-treated by a dynamic headspace method, a VOC environmental chamber method or a headspace-solid phase microextraction method to collect mixed odor substances in the test sample.

[0012] Further, the dynamic headspace method conditions include: incubation temperature: 50-65°C, incubation time: 25-35min, shaking speed: 450-550rpm, capture volume: 1L, capture flow: 60-90ml / min, adsorption trap temperature: 25-35°C, dry blow volume: 600mL, dry blow flow: 25-35mL / min, adsorption trap temperature during dry blow: 25-35°C;

[0013] Thermal desorption conditions: heating rate: 150-220℃ / min, final temperature: 250-270℃, holding time: 4-6min, transfer line temperature: 250-270℃;

[0014] Cold trap conditions: initial temperature: -50°C, heating rate: 5-15°C / S, final temperature: 250-270°C, holding time: 4-6min;

[0015] The conditions of the VOC environmental chamber method include:

[0016] VOC chamber test conditions: VOC chamber temperature: 22.5-23.5℃, VOC chamber relative humidity: 42-48%, load rate: 0.98-1.02m 2 / m 3 , air replacement rate: 0.95-1.05h -1 , air velocity on sample surface: 0.95-1.05m / s;

[0017] Air sampling conditions: start sampling time: 70-74h after the start of the test; sampling flow rate: 100-500mL / min; sampling time: 12-60min;

[0018] The thermal desorption conditions and cold trap conditions are the same as those in the dynamic headspace method;

[0019] The headspace-solid phase microextraction conditions include:

[0020] Extraction conditions: extraction head: DVB-CAR-PDMS; extraction adsorption time: 15-60min, extraction temperature 50-100℃, desorption time 3-5min.

[0021] Furthermore, in step 3, it includes:

[0022] S301: Separating mixed odor substances by gas chromatography, and diverting and transporting the separated single odor substances to a mass spectrometer detection location;

[0023] S302: Obtain a mass spectrum of a single odor substance using mass spectrometry detection technology, and compare the mass spectrum of the odor substance with material data in a mass spectrometry library to determine the chemical composition of the odor substance.

[0024] Further, in the step S301, when the dynamic headspace method or the VOC environmental chamber method is used to pre-treat the sample, the gas chromatography analysis conditions are: chromatographic column: DM-TVOC quartz capillary chromatographic column or similar model chromatographic column; injection port temperature: 240-260°C; carrier gas is helium; flow rate: 1.5-1.6mL / min; heating program: initial temperature is 40-60°C, maintained for 1-3min, heated to 110-125°C at a rate of 5-15°C / min, maintained for 5-15min; then heated to 150-170°C at a rate of 4-6°C / min, maintained for 5-10min; heated to 180-220°C at a rate of 4-6°C / min, maintained for 5-15min; finally heated to 240-260°C at a rate of 4-6°C / min, maintained for 4-6min;

[0025] When the headspace-solid phase microextraction method is used for pretreatment of the sample, the gas chromatography analysis conditions are: chromatographic column: DB-624 quartz capillary chromatographic column (60m×0.25mm×0.25μm) or similar model chromatographic column; injection port temperature: 240-260°C; carrier gas is helium; flow rate: 1.0mL / min; program temperature conditions are: starting temperature is 40-60°C, maintained for 1-3min, heated to 150-160°C at a rate of 5-20°C / min, maintained for 3-10min; then heated to 180-200°C at a rate of 1-10°C / min, maintained for 5-10min; finally heated to 230-260°C at a rate of 5-15°C / min and maintained for 10-15min;

[0026] Among them, in the gas chromatography separation stage, the collected samples are split or not split when entering the gas chromatograph;

[0027] In step S302, the mass spectrometry analysis conditions are: interface temperature of 260-300°C, quadrupole temperature of 140-160°C, EI ion source temperature of 220-240°C, electron energy of 60-80 eV, and mass scanning range of 45-550 m / z.

[0028] Furthermore, in step S302, gas chromatography-mass spectrometry is used to obtain a mass spectrum of a single odor substance, and the mass spectrum of the odor substance is compared with the material data in the mass spectrum library. For odor substances with a similarity of not less than 85%, the chemical composition of the odor substance is determined based on the material mass spectrum fragment data in the mass spectrum library.

[0029] Furthermore, in step 4, it includes:

[0030] S401: while completing the qualitative analysis of the odor substance, using a carrier gas to transport the odor substance to an olfactometer for artificial olfaction to obtain the odor category and odor intensity of the odor substance;

[0031] S402: adjusting the split ratio of the sample when it enters the gas chromatograph to obtain the minimum odor intensity of the odor substance;

[0032] S403: When the odor intensity of the odor substance is the lowest, the concentration of the odor substance is detected and obtained, and the concentration is used as the odor threshold of the odor substance.

[0033] Furthermore, in the step S401, after the sample is separated by the chromatographic column, it is split by a valve, with one part entering the olfaction port of the olfactometer and the other part entering the mass spectrometer;

[0034] When the dynamic headspace method and the VOC environmental chamber method are used for pretreatment of the sample, the ratio of the flow rate entering the olfactory port to the flow rate entering the mass spectrometer end is adjusted to 1:1, and based on the length and inner diameter of the chromatographic column, the length of the empty column connected to the mass spectrometer end and the olfactory end after the three-way valve is determined; wherein, the empty columns of the olfactory and mass spectrometer are connected to the three-way valve, and the tail pressure of the chromatographic column is adjusted to 2.9-3.0PSI;

[0035] When the headspace-solid phase microextraction method is used for pretreatment of the sample, the ratio of the flow rate entering the olfactory port to the flow rate entering the mass spectrometer port is adjusted to 1:1 or 7:3, and the length of the empty column connected to the mass spectrometer port and the olfactory port after the four-way valve is determined based on the length and inner diameter of the chromatographic column;

[0036] In step S402, other parameters of the instrument are kept unchanged and the split ratio is gradually increased; wherein the split ratio is: no split, 15:1, 25:1, 30:1, 50:1, 75:1, 80:1, 90:1, 95:1, 100:1, 200:1.

[0037] On the one hand, the embodiment of the present invention provides the olfactory threshold of the odorous substance of the board obtained by using the olfactory threshold determination method of the odorous substance of the artificial board;

[0038] Wherein, the board material includes artificial board and its raw materials.

[0039] Furthermore, the olfactory threshold includes the olfactory threshold of terpenes in radiata pine and the olfactory threshold of terpenes in masson pine;

[0040] Among them, the olfactory thresholds of terpenes in radiata pine include:

[0041]

[0042]

[0043] Among them, the olfactory thresholds of terpenes in Masson pine include:

[0044]

[0045] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0046] 1. The present invention uses gas chromatography in gas chromatography-mass spectrometry to separate the collected mixed odor substances, and obtains the mass spectrum of the separated single odor substance through the mass spectrometer in the gas chromatography-mass spectrometry, compares and determines the category of the odor substance based on the mass spectrum fragment data of the odor substance in the NIST17.0 database, completes the qualitative analysis of the odor substance, and uses a carrier gas to transport the odor substance to an olfactometer for artificial smelling. The odor threshold of the obtained odor substance is lower than the odor threshold of the existing recorded odor substance, thereby improving the accuracy of the odor threshold detection of the odor substance in the artificial board and avoiding the omission of harmful gas substances.

[0047] 2. When determining the olfactory threshold of odorous substances in artificial boards, no standard samples or chromatographic sample preparation are required to achieve the olfactory threshold of the compound, thus reducing the detection cost.

[0048] 3. Compared with the traditional dilution method, the error introduced by the dilution process is reduced during the operation. In the detection process, the gas chromatography has a strong separation ability and can eliminate the interference of other compounds. The mass spectrometry detection has high accuracy and objectivity, and has good signals for trace compounds, which improves the sensitivity of detection.

[0049] 4. For artificial boards and their products containing multiple odor compounds, the odor and odor intensity of multiple odor compounds can be determined at one time, thereby improving detection efficiency.

[0050] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0052] Figure 1 This is the mass spectrum of 3-carene in radiata pine;

[0053] Figure 2 is the standard mass spectrum of 3-carene;

[0054] Figure 3 This is the mass spectrum of β-pinene in radiata pine;

[0055] Figure 4 is the standard mass spectrum of β-pinene;

[0056] Figure 5 This is the mass spectrum of fenchol in radiata pine;

[0057] Figure 6 is the standard mass spectrum of fenchol;

[0058] Figure 7 The present invention is a flow chart of the method for determining the odor threshold of odor substances in artificial boards. DETAILED DESCRIPTION

[0059] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0060] The dynamic dilution method is the dynamic dilution olfactometer test method, which is to dilute the standard odor substances in a gradient manner, and take the lowest concentration detected by humans as the detected odor threshold. However, due to the large variety of odor substances in artificial boards, the boiling points of terpene components in odor substances are mostly above 100°C. When the dynamic dilution method is used to determine the odor threshold, some odor substances will condense and deposit, and the concentration of odor substances needs to be increased to smell the odor, resulting in the detected odor threshold being higher than the actual value.

[0061] After obtaining the odor threshold, the odor activity value is obtained based on the ratio of the mass concentration of the odor substance to the odor threshold. The larger the odor activity value, the greater the impact of the odor substance on the human body. The odor threshold obtained by the existing odor threshold measurement method is too high, resulting in the odor activity being lower than the actual value, which affects the judgment of the odor substance, resulting in unclear control objects and omissions of harmful odor substances, which affects the treatment strategy of artificial boards, resulting in the odor not being controlled, affecting human habitation.

[0062] In order to solve the above problems, the present invention provides a method for determining the olfactory threshold of odor substances in artificial boards, comprising:

[0063] Step 1: Prepare test sample;

[0064] Step 2: Pre-treat the test sample and collect the mixed odor substances in the test sample;

[0065] Step 3: Separate the mixed odor substances by gas chromatography, and send the separated single odor substances to the mass spectrometer for qualitative analysis of the odor substances;

[0066] Step 4: While completing the qualitative analysis of the odor substance, use carrier gas to transport the odor substance to the olfactometer for artificial olfaction, adjust the split ratio at the injection port, and measure the olfactory threshold of each odor substance.

[0067] Among them, gas chromatography-mass spectrometry is used to obtain a mass spectrum of a single odor substance, and the mass spectrum of the odor substance is compared with the material data in the mass spectrum library, such as the material data in the NIST17.0 database. For odor substances with a similarity of not less than 85%, the chemical composition of the odor substance is determined based on the material mass spectrum fragment data in the NIST17.0 database.

[0068] Among them, for odor substances with a similarity of less than 85%, the substance is marked as unknown substance X, and X is a natural number such as 1, 2, 3, etc. Then, based on the mass spectrum data of the substance, combined with literature research and relevant theoretical knowledge, manual spectrum analysis is performed to determine the chemical composition of the substance.

[0069] Among them, artificial sniffing determines the type and intensity of odor. For the lowest odor intensity that can be smelled by humans, the external standard method is used to measure the mass concentration of the odor substance at the lowest odor intensity. This concentration is the olfactory threshold of the odor substance.

[0070] Compared with the prior art, the present invention uses gas chromatography in gas chromatography-mass spectrometry to separate the collected mixed odor substances, and obtains the mass spectrum of the separated single odor substance through the mass spectrometer in the gas chromatography-mass spectrometry, and compares and determines the category of the odor substance based on the mass spectrum fragment data of the substance in the NIST17.0 database. While completing the qualitative analysis of the odor substance, the odor substance is transported to the olfactometer by carrier gas for artificial smelling. The odor threshold of the obtained odor substance is lower than the odor threshold of the existing recorded odor substance, which improves the accuracy of the odor threshold detection of the odor substance of the artificial board and avoids missing harmful gas substances.

[0071] Specifically, in step 1, the test sample is an artificial board and its raw materials, and its material can be wood raw materials such as radiata pine, masson pine, etc., or it can be raw materials or semi-finished products such as shavings, fibers, veneers used in the processing of artificial boards, or it can be auxiliary materials such as adhesives and paraffin added in the processing of artificial boards, or it can be finished artificial boards.

[0072] Among them, dynamic headspace and headspace-solid phase microextraction pretreatment can be used. At this time, when loading, the length, width and thickness of the sample are 25mm*7mm*6mm, so that it can be smoothly placed in a 20mL headspace bottle to ensure that a higher concentration of volatile components enters the gas chromatography injection port. If this size is not reached, for solid samples, more mass samples should be selected for analysis as much as possible, and for liquid samples with more volatile components, only about 1g of weight needs to be weighed for injection.

[0073] Among them, VOC environmental chamber pretreatment can be adopted. At this time, when loading the sample, the length and width of the sample are 500mm*500mm, and there is no requirement for thickness.

[0074] Specifically, in step 2, the test sample can be pre-treated by headspace-solid phase microextraction, dynamic headspace (DHS) and VOC environmental chamber method to collect mixed odor substances in the test sample.

[0075] Among them, the appropriate pretreatment method is selected according to the state of the sample and the content of the odorous substances of concern in the sample. For example, for small-sized solid or liquid samples such as wood blocks, wood shavings, wood fibers, adhesives, etc., the dynamic headspace method or headspace-solid phase microextraction method is selected; for large-sized solid samples such as artificial boards and wooden veneers, the VOC environmental chamber method is selected.

[0076] The dynamic headspace conditions include: incubation temperature: 50-65°C, incubation time: 25-35min, shaking speed: 450-550rpm, capture volume: 1L, capture flow: 60-90ml / min, adsorption trap temperature: 25-35°C, dry blowing volume: 600ml, dry blowing flow: 25-35ml / min. Adsorption trap temperature during dry blowing: 25-35°C.

[0077] VOC environmental chamber conditions include: VOC chamber temperature: 22.5-23.5℃, VOC chamber relative humidity: 42-48%, load rate: 0.98-1.02m 2 / m 3 , air replacement rate: 0.95-1.05h -1 , air flow rate on sample surface: 0.95-1.05m / s.

[0078] Air sampling conditions: start sampling time: 70-74h after the start of the test; sampling flow rate: 100-500mL / min; sampling time: 12-60min.

[0079] Thermal desorption conditions: heating rate: 150-220°C / min, final temperature: 250-270°C, holding time: 4-6min, transfer line temperature: 250-270°C.

[0080] Cold trap conditions: initial temperature: -50°C, heating rate: 5-15°C / s, final temperature: 250-270°C, holding time: 4-6 min.

[0081] Among them, head space-solid phase microextraction (HS-SPME) can also be used to pre-treat the test samples to collect mixed odor substances in the test samples.

[0082] The extraction conditions include: extraction head: DVB-CAR-PDMS; extraction adsorption time: 15-60min, extraction temperature 50-100°C, and desorption time 3-5min.

[0083] Specifically, step 3 includes:

[0084] S301: Separating mixed odor substances by gas chromatography, and diverting and transporting the separated single odor substances to a mass spectrometer detection location;

[0085] S302: Obtain a mass spectrum of a single odor substance using mass spectrometry detection technology, and compare the mass spectrum of the odor substance with material data in a mass spectrometry library to determine the chemical composition of the odor substance.

[0086] Specifically, in S301, when the dynamic headspace method and the VOC environmental chamber method are used to pre-treat the sample, at this time, the gas chromatography analysis conditions are: DM-TVOC quartz capillary column (50m×0.32mm×1μm); inlet temperature 240-260℃; carrier gas is helium; flow rate is 1.5-1.6mL / min; heating program is: initial temperature is 40-60℃, maintained for 1-3min, heated to 110-125℃ at a rate of 5-15℃ / min, maintained for 5-15min; then heated to 150-170℃ at a rate of 4-6℃ / min, maintained for 5-10min; heated to 180-220℃ at a rate of 4-6℃ / min, maintained for 5-15min; finally heated to 240-260℃ at a rate of 4-6℃ / min, maintained for 4-6min.

[0087] When the headspace-solid phase microextraction method is used for pretreatment of the sample, the gas chromatography analysis conditions are as follows: chromatographic column: DB-624 quartz capillary chromatographic column (60m×0.25mm×0.25μm); inlet temperature: 240-260°C; carrier gas is helium; flow rate: 1.0mL / min; programmed temperature conditions are as follows: the starting temperature is 40-60°C, maintained for 1-3min, heated to 150-160°C at a rate of 5-20°C / min, maintained for 3-10min; then heated to 180-200°C at a rate of 1-10°C / min, maintained for 5-10min; finally heated to 230-260°C at a rate of 5-15°C / min, maintained for 10-15min.

[0088] Furthermore, under this condition, it is ensured that multiple odor substances can be separated, and the peak time of two odor substances with similar polarity is prolonged to ensure that the odors of the two odor substances with similar polarity will not affect each other.

[0089] In the gas chromatography separation stage, the collected samples are split or not split when entering the gas chromatograph. When split, the split ratio can be (0-200):1.

[0090] Specifically, in S302, the mass spectrometry analysis conditions are: interface temperature of 260-300°C, quadrupole temperature of 140-160°C, EI ion source temperature of 220-240°C, electron energy of 60-80 eV, and mass scanning range of 45-550 m / z.

[0091] If the mass spectrum of the odor substance to be detected has a low similarity with the mass spectrum in the existing mass spectrum library, the odor substance may be a new substance not recorded in the mass spectrum library. Based on the mass spectrum data of the odor substance, combined with literature research and relevant theoretical knowledge, the chemical composition of the substance is determined through manual spectrum analysis, and the mass spectrum library is updated.

[0092] For example, Figure 1-2 As shown, it represents the mass spectrum of 3-carene in radiata pine and the standard mass spectrum of 3-carene; Figure 3-4 As shown, it represents the mass spectrum of left-β-pinene in radiata pine and the standard mass spectrum of β-pinene; Figure 5-6 As shown, the mass spectrum of fenchol in radiata pine and the standard mass spectrum of fenchol; thus, the chemical composition of the odor substance can be determined by comparing the mass spectrum of the odor substance with the material data in the mass spectrum library.

[0093] Specifically, step 4 includes:

[0094] S401: while completing the qualitative analysis of the odor substance, using a carrier gas to transport the odor substance to an olfactometer for artificial olfaction to obtain the odor category and odor intensity of the odor substance;

[0095] S402: adjusting the split ratio of the sample when it enters the gas chromatograph to obtain the minimum odor intensity of the odor substance;

[0096] S403: When the odor intensity of the odor substance is the lowest, the mass concentration of the odor substance is detected and obtained, and the concentration is used as the odor threshold of the odor substance.

[0097] Specifically, in step S401, after the sample is separated by the chromatographic column, it is split by a valve, with one part entering the olfaction port of the olfactometer and the other part entering the mass spectrometer.

[0098] Furthermore, the ratio of the flow rate entering the sniffing port to the flow rate entering the mass spectrometer port is adjusted, and based on the length and inner diameter of the chromatographic column, the length of the empty column connected to the mass spectrometer port and the sniffing port after the valve is determined.

[0099] Exemplarily, the dynamic headspace method and the VOC environmental chamber method are used to pre-treat the sample. At this time, a three-way valve is used to control the flow rate entering the olfactory port and the flow rate entering the mass spectrometer end, and the flow ratio is 1:1. After determining the column type and the flow ratio entering the olfactory port and the mass spectrometer end, open the software Gerstel ODP Calculator, enter the length and inner diameter of the chromatographic column, and the flow ratio to the olfactory port and the mass spectrometer end, and the length of the empty column connected to the mass spectrometer end and the olfactory end after the three-way valve can be calculated.

[0100] Furthermore, the empty columns at the olfactory end and the mass spectrometer end are connected to the three-way valve, and the tail pressure of the chromatographic column is adjusted to ensure that the substance can reach the mass spectrometer end and the olfactory end at the same time, realizing synchronous detection and preventing air leakage caused by the low vacuum back suction of the mass spectrometer.

[0101] Furthermore, after the empty columns at the olfactory end and the mass spectrometer end were connected to the three-way valve, the column tail pressure was set to 2.9-3.0 PSI in the GC-MS workstation software.

[0102] Exemplarily, the headspace-solid phase microextraction method is used for pretreatment of the sample. At this time, a four-way valve is used to control the flow rate entering the olfactory port and the flow rate entering the mass spectrometry end. The flow ratio is 1:1 or 7:3. After determining the column type and the flow ratio entering the olfactory port and the mass spectrometry end, open the software Split Manager, enter the length and inner diameter of the chromatographic column, and the flow ratio of the olfactory port and the mass spectrometry end, and then calculate the length of the empty column connected to the mass spectrometry end and the olfactory end after the four-way valve and the flow rate of the make-up gas.

[0103] Furthermore, the empty columns at the olfactory end and the mass spectrometer end are connected to the four-way valve, and then a supplementary gas is connected to ensure that the substance can reach the mass spectrometer end and the olfactory end at the same time, realizing synchronous detection and preventing the low vacuum air from being sucked back by the mass spectrometer and leaking.

[0104] Exemplarily, after the empty columns at the olfactory end and the mass spectrometer end are connected to the four-way valve, the flow rate of the supplementary gas is 5 mL / min.

[0105] The odor intensity is judged by an odor evaluation team consisting of three members who have no smoking history and no olfactory organ disease. The odor intensity is judged based on the "Odor Prevention Law" promulgated by the Ministry of the Environment of Japan.

[0106] Among them, the difference in olfactory threshold results obtained by the three evaluators should be within 20% of the arithmetic mean, otherwise the samples should be re-prepared and re-smelled.

[0107] Specifically, in step S402, keep other parameters of the instrument unchanged, and gradually increase the diversion ratio to reduce the amount of odor substances until a barely perceptible odor is smelled. Exemplarily, the diversion ratio can be: no diversion, 15:1, 25:1, 30:1, 50:1, 75:1, 80:1, 90:1, 95:1, 100:1, 200:1.

[0108] In the process of gradually increasing the diversion ratio, the amount of odor substances is gradually reduced, so that the previous diversion ratio when the odor substances can no longer be smelled becomes the diversion ratio when the odor is barely detectable; for example, when the diversion ratio is 80:1, the odor can just not be smelled, and the diversion ratio for smelling the odor that is barely detectable is 75:1.

[0109] Specifically, in step S403, toluene is used as a standard substance and an external standard method is used to perform quantitative analysis to determine the concentration of the odorous substance.

[0110] Among them, the concentration measurement method of odor substances includes:

[0111] 1) Using the concentration of toluene as the abscissa and the peak area of ​​toluene at different masses as the ordinate, a standard curve is drawn;

[0112] 2) Substitute the peak area of ​​the odor substance when the odor can be barely perceived into the above standard curve to calculate the mass of the odor substance, and calculate the olfactory threshold of the odor substance based on the volume of air extracted during the sampling process.

[0113] Compared with the prior art, the present invention uses gas chromatography in gas chromatography-mass spectrometry to separate the collected mixed odor substances, and obtains the mass spectrum of the separated single odor substance through the mass spectrometer in the gas chromatography-mass spectrometry instrument, and compares and determines the chemical composition of the odor substance based on the mass spectrum fragment data of the substance in the NIST17.0 database. While completing the qualitative analysis of the odor substance, the odor substance is transported to the olfactometer by carrier gas for artificial smelling. The odor threshold of the obtained odor substance is lower than the odor threshold of the existing recorded odor substance, which improves the accuracy of the odor threshold detection of the odor substance of the artificial board and avoids missing harmful gas substances.

[0114] When determining the olfactory threshold of odorous substances in artificial boards, no standard samples or chromatographic sample preparation are required to achieve the olfactory threshold of the compound, thereby reducing the detection cost.

[0115] Compared with the traditional dilution method, the error introduced by the dilution process is reduced during the operation. In the detection process, the gas chromatography has a strong separation ability and can eliminate the interference of other compounds. The mass spectrometry detection has high accuracy and objectivity, and has good signals for trace compounds, which improves the sensitivity of detection.

[0116] For artificial boards and products thereof containing multiple odor compounds, the odors and odor intensities of multiple odor compounds can be determined at one time, thereby improving detection efficiency.

[0117] Example 1

[0118] Radiata pine was used as the raw material for wood-based panels and the odor threshold in the wood raw material was determined.

[0119] Specifically, the method for determining the odor threshold of odor substances of a wood-based panel using radiata pine as a wood raw material comprises the following steps:

[0120] Step 1: Prepare test sample;

[0121] Specifically, when the dynamic headspace method is used to pre-treat the sample, the radiata pine wood block is cut into wood chips of about 25 mm*7 mm*6 mm in size, added to a 20 mL headspace bottle, and sealed with a cap. After being numbered, it is placed in the sample tray of the sampler for GC-MS-O analysis.

[0122] Step 2: pre-treat the test sample and collect the mixed odor substances in the test sample;

[0123] Specifically, the dynamic headspace method is used to pre-treat the test sample to collect the mixed odor substances in the test sample.

[0124] The dynamic headspace conditions include: incubation temperature: 60°C, incubation time: 30 min, shaking speed: 500 rpm, capture volume: 1 L, capture flow rate: 80 ml / min, adsorption trap temperature: 30°C, dry blow volume: 600 ml, dry blow flow rate: 30 ml / min. Adsorption trap temperature during dry blow: 30°C.

[0125] Thermal desorption conditions: heating rate: 200 °C / min, final temperature: 260 °C, holding time: 5 min, transfer line temperature: 260 °C.

[0126] Cold trap conditions: initial temperature: -50°C, heating rate: 10°C / S, final temperature: 260°C, holding time: 5 min.

[0127] Step 3: Separate the mixed odor substances by gas chromatography, and send the separated single odor substances to the mass spectrometer for qualitative analysis of the odor substances;

[0128] Specifically, they include:

[0129] S301: Separating mixed odor substances by gas chromatography, and diverting and transporting the separated single odor substances to a mass spectrometer detection location;

[0130] Among them, the gas chromatography analysis conditions are: DM-TVOC quartz capillary column (50m×0.32mm×1μm); injection port temperature 250℃; carrier gas is helium; flow rate is 1.53mL / min; heating program is: initial temperature is 50℃, keep for 2min, increase to 120℃ at a rate of 10℃ / min, keep for 10min; then increase to 160℃ at a rate of 5℃ / min, keep for 10min; increase to 200℃ at a rate of 5℃ / min, keep for 10min; finally increase to 250℃ at a rate of 5℃ / min and keep for 5min.

[0131] Among them, in the gas chromatography separation stage, the collected odor substance samples are not split when entering the gas chromatograph.

[0132] S302: Obtain a mass spectrum of a single odor substance using mass spectrometry detection technology, and compare the mass spectrum of the odor substance with the substance data in the NIST17.0 database to determine the chemical composition of the odor substance.

[0133] Among them, the mass spectrometry analysis conditions are: the mass spectrometry analysis conditions are: the interface temperature is 280°C, the quadrupole temperature is 150°C, the EI ion source temperature is 230°C, the electron energy is 70eV, and the mass scanning range is 45-550m / z.

[0134] Among them, Agilent gas chromatography-mass spectrometry instruments and Shimadzu gas chromatography-mass spectrometry instruments both directly compare and determine the chemical composition of odorous substances based on the NIST17.0 database.

[0135] Step 4: While completing the qualitative analysis of the odor substance, use carrier gas to transport the odor substance to the olfactometer for artificial smelling, adjust the diversion ratio, and measure the olfactory threshold of each odor substance.

[0136] Specifically, they include:

[0137] S401: while completing the qualitative analysis of the odor substance, using a carrier gas to transport the odor substance to an olfactometer for artificial olfaction to obtain the odor category and odor intensity of the odor substance;

[0138] Specifically, after the sample is separated by the chromatographic column, it is diverted by a valve, with one part entering the olfaction port of the olfactometer and the other part entering the mass spectrometer.

[0139] Adjust the ratio of the flow rate entering the sniffing port to the flow rate entering the mass spectrometer end, and determine the length of the empty column connected to the mass spectrometer end and the sniffing end after the valve based on the length and inner diameter of the chromatographic column.

[0140] Among them, for Agilent equipment, the chromatographic column uses a TVOC chromatographic column, and the ratio of the flow entering the olfactory port to the flow entering the mass spectrometer end is 1:1. After determining the column type and the flow ratio between the olfactory port and the mass spectrometer end, open the Gerstel ODP Calculator software, enter the length and inner diameter of the chromatographic column, and the flow ratio between the olfactory port and the mass spectrometer end, and you can calculate the length of the empty column connected to the mass spectrometer end and the olfactory end after the three-way valve.

[0141] Specifically, the empty columns of the olfactory and mass spectrometers were connected to the three-way valve, and the column tail pressure was set to 2.9-3.0 Psi in the GC-MS workstation software to ensure that the substance could reach the mass spectrometer end and the olfactory end at the same time to achieve synchronous detection and prevent air leakage caused by the low vacuum back suction of the mass spectrometer.

[0142] For Shimadzu equipment (headspace-solid phase microextraction method), the chromatographic column uses a DB-624 quartz capillary chromatographic column (60m×0.25mm×0.25μm), and the ratio of the flow rate entering the olfactory port to the flow rate entering the mass spectrometer end is 7:3. After determining the column type and the flow rate ratio between the olfactory port and the mass spectrometer end, open the Split Manager, enter the length and inner diameter of the chromatographic column, and the flow rate ratio between the olfactory port and the mass spectrometer end, and then you can calculate the length of the empty column after the valve connected to the mass spectrometer end and the olfactory end and the flow rate of the make-up gas.

[0143] Specifically, the empty columns of the olfactory and mass spectrometers are connected to the four-way valve, and then the supplementary gas is connected to one end of the four-way valve. The supplementary gas is helium, and the supplementary gas flow rate is 5mL / min. This ensures that the substance can reach the mass spectrometer end and the olfactory end at the same time to achieve synchronous detection, and prevent the low vacuum air from being sucked back and leaking the mass spectrometer.

[0144] The transmission line temperature of the olfactometer is 260°C, and high-purity nitrogen is used as the carrier gas to perform odor characteristic analysis on odorous substances.

[0145] Among them, odor characteristics include odor type and odor intensity.

[0146] Among them, the odor intensity is determined by artificial sniffing by the odor evaluation team, which consists of 3 members with no smoking history and no olfactory organ disease.

[0147] Among them, the difference in olfactory threshold results obtained by the three evaluators should be within 20% of the arithmetic mean, otherwise the samples should be re-prepared and re-smelled.

[0148] Among them, the judgment of odor intensity refers to the "Odor Prevention Law" promulgated by the Ministry of the Environment of Japan. The specific evaluation standards are shown in Table 2.

[0149] Table 2 Japanese odor intensity judgment standard

[0150]

[0151] S402: adjusting the split ratio of the sample when it enters the gas chromatograph to obtain the minimum odor intensity of the odor substance;

[0152] Herein, the split ratio is the split ratio of the gas chromatography, and the result is equal to the amount of sample emptied / the amount of sample entering the chromatographic column. Exemplarily, the split ratio is 10:1, that is, the sample is divided into 11 parts after entering the injection port, of which 1 part enters the chromatographic column for analysis, and 10 parts are discharged through the drain valve and do not enter the analysis system.

[0153] Among them, keeping other parameters of the instrument unchanged, gradually increase the diversion ratio to reduce the amount of odor substances, until a barely perceptible odor is smelled. At this time, the minimum olfactory detection concentration of the main odor substances in the wood is measured, that is, the olfactory threshold.

[0154] Specifically, olfactory experiments were conducted under the conditions of no split, 15:1, 25:1, 30:1, 50:1, 75:1, 80:1, 90:1, 95:1, 100:1, and 200:1, and the odor type and odor intensity of the substance were recorded.

[0155] Among them, multiple people measure each sample at the same time, and the final olfactory threshold of the odor substance is determined based on the average threshold of the team members calculated based on the personal threshold of the olfactory detectives.

[0156] S403: When the odor intensity of the odor substance is the lowest, the mass concentration of the odor substance is detected and obtained, and the concentration is used as the odor threshold of the odor substance.

[0157] Among them, the concentration detection method uses toluene as the standard substance and adopts the external standard method for quantitative analysis. The specific operation steps are as follows:

[0158] 1) Using the concentration of toluene as the abscissa and the peak area of ​​toluene at different concentrations as the ordinate, a standard curve is drawn;

[0159] Cut a 7mm×25mm filter paper strip and place it in a 20mL headspace bottle. Prepare a series of toluene concentration gradient standard samples, use a micro syringe to draw 5 microliters of standard sample and slowly inject it from the top of the filter paper strip, quickly cover the bottle cap, and perform GC-MS analysis. Draw a standard curve with toluene mass as the horizontal axis and toluene peak area as the vertical axis.

[0160] 2) Substitute the peak area of ​​the odor substance when the odor can be barely perceived into the above standard curve to calculate the mass of the odor substance, and calculate the olfactory threshold of the odor substance based on the volume of air extracted during the sampling process.

[0161] The results of the olfactory threshold test of natural terpenes in radiata pine are shown in Table 3:

[0162] Table 3 Odor thresholds of terpenes in radiata pine

[0163]

[0164] Example 2

[0165] Using Masson pine as the raw material for wood-based panels, the odor threshold of the wood raw material was determined.

[0166] The difference between the method for determining the odor threshold of odor substances of artificial boards and that of Example 1 lies in step 1 and step S402.

[0167] Specifically, in step 1, it includes:

[0168] Fresh Masson pine wood was sawn into logs with a thickness of about 7 mm, and treated in an oven at 60°C for 70 min. Each test was conducted with a wood strip with a width of about 6 mm and a length of 25 mm along the longitudinal section. The sample was added to a 20 mL headspace bottle and sealed. After being numbered, it was placed in the sample tray of the injector for GC-MS-O analysis.

[0169] Each sample shall be tested for a maximum of three times, and new samples shall be prepared after more than three times.

[0170] Specifically, in step S402, it includes:

[0171] The olfactory experiment was carried out at split ratios of 5:1, 10:1, 15:1, 20:1, 25:1, 35:1, and 50:1, and the odor type and odor intensity of the substance were recorded.

[0172] The results of the olfactory threshold test of natural terpenes in Masson pine are shown in Table 4:

[0173] Table 4 Odor thresholds of terpenes in Masson pine

[0174]

[0175] Example 3

[0176] The difference from Example 1 is that the headspace-solid phase microextraction method is used to pre-treat the sample.

[0177] Specifically, in step 2, the extraction conditions include: extraction head: DVB-CAR-PDMS; extraction adsorption time: 30 min, extraction temperature 60° C., and desorption time 3 min.

[0178] Specifically, in step S301, the gas chromatography analysis conditions are: DB-624 quartz capillary column (60m×0.25mm×0.25μm); injection port temperature 250°C; carrier gas is helium; flow rate is 1.0mL / min; program temperature conditions are: starting temperature is 60°C, maintained for 1min, heated to 160°C at a rate of 20°C / min, maintained for 3min; then heated to 180°C at a rate of 2°C / min, maintained for 5min; finally heated to 230°C at a rate of 5°C / min and maintained for 15min.

[0179] Among them, in the gas chromatography separation stage, the collected odor substance samples are not split when entering the gas chromatograph.

[0180] Specifically, in step S401, for Shimadzu equipment, the chromatographic column uses a DB-624 quartz capillary chromatographic column (60m×0.25mm×0.25μm), and the ratio of the flow rate entering the olfactory port to the flow rate entering the mass spectrometer end is 7:3. After determining the column type and the flow rate ratio between the olfactory port and the mass spectrometer end, open the Split Manager, enter the length and inner diameter of the chromatographic column, and the flow ratio between the olfactory port and the mass spectrometer end, and then calculate the length of the empty column connected to the mass spectrometer end and the olfactory end after the valve and the flow rate of the make-up gas.

[0181] Specifically, the empty columns of the olfactory and mass spectrometers are connected to the four-way valve, and then the supplementary gas is connected to one end of the four-way valve. The supplementary gas is helium, and the supplementary gas flow rate is 5mL / min. This ensures that the substance can reach the mass spectrometer end and the olfactory end at the same time to achieve synchronous detection, and prevent the low vacuum air from being sucked back and leaking the mass spectrometer.

[0182] Example 4

[0183] The difference from Example 1 is that the sample is pre-treated using a VOC environmental chamber method.

[0184] Specifically, in step 1, the radiata pine veneer is cut into samples with a size of 500 mm×500 mm×plate thickness, and two samples are taken, sealed on all sides with formaldehyde-free aluminum tape and placed in a VOC environmental chamber.

[0185] Specifically, in step 2, the conditions of the VOC environmental chamber method include: VOC chamber test conditions: VOC chamber temperature: 23°C, VOC chamber relative humidity: 45%, load rate: 1.00m 2 / m 3 , air replacement rate: 1.00h -1 , air flow rate on sample surface: 1.00m / s.

[0186] Air sampling conditions: start sampling time: 72 hours after the start of the test; sampling flow rate: 200 mL / min; sampling time: 30 min.

[0187] Thermal desorption conditions: heating rate: 200 °C / min, final temperature: 260 °C, holding time: 5 min, transfer line temperature: 260 °C.

[0188] Cold trap conditions: initial temperature: -50°C, heating rate: 10°C / S, final temperature: 260°C, holding time: 5 min.

[0189] Comparative Example 1

[0190] The dynamic dilution olfactometer test method is used to detect the olfactory thresholds of the main terpene compounds in wood, including:

[0191] 1) Identify the main terpene odor compounds in wood and purchase standards;

[0192] 2) Identify at least 5 odor detectors, all of whom must meet the requirements for odor detectors in GB / T 14675-93 "Determination of air quality odor - three-point comparison odor bag method";

[0193] 3) Use a dynamic diluter to prepare a certain concentration of standard gas, and select a concentration that can clearly smell the odor but is not strongly irritating as the initial dilution multiple;

[0194] 4) The odor samples were diluted step by step according to GB / T 14675-93 "Determination of air quality odor - three-point comparison odor bag method", and the dilution gradient is shown in Table 5 below.

[0195] Table 5 Dilution gradient of odor samples

[0196]

[0197] Among them, three odorless bags are prepared for each dilution multiple, one of which is quantitatively injected with standard gas according to the correct initial dilution multiple, and the other two are filled with clean air. Then, the odorists will perform the odor identification and pick out the odorous bags. After all the odor identifications are completed, the next level of dilution multiple test is carried out until the maximum concentration that each odorist makes an error and the minimum concentration that is correctly identified are found. The individual odor threshold is calculated according to formula (1), and the maximum and minimum values ​​of the group's individual odor thresholds are discarded, and the arithmetic average threshold of the group is calculated;

[0198]

[0199] Among them, X i is the personal olfactory threshold;

[0200] a1 is the maximum dilution factor of the individual correct answer;

[0201] a2 is the dilution factor due to personal misunderstanding.

[0202] 5) The olfactory threshold test for each standard gas was carried out 5 times.

[0203] Among them, the olfactory threshold of the terpene compounds mainly extracted in Example 1-2 is compared with the olfactory threshold determined by the method of Comparative Example 1, as shown in Table 6 below.

[0204] Table 6 Olfactory threshold detection values ​​of terpene compounds in Examples 1-2 and Comparative Example 1

[0205]

[0206]

[0207] Among them, “-” means that there is no such data.

[0208] It can be seen from Table 6 that for the olfactory thresholds of borneol, verbenone, caryophyllene and humulene in wood, the olfactory thresholds of terpenes in wood detected by the method of Examples 1-2 are lower than the olfactory thresholds of terpenes measured in Comparative Example 1, that is, the olfactory threshold detection value is lower than the olfactory threshold recorded in the literature, that is, the odor substance activity value calculated based on the olfactory threshold obtained by the method of Comparative Example 1 is lower than the actual value, which affects the judgment of the odor activity value.

[0209] At present, the existing literature does not record the olfactory thresholds of α-phellandrene, γ-terpinene, terpinolene, fenchol, myrtenol, β-myrcene, α-terpinene, trans-β-ocimene, α-borneol, trans-hinokitiol, estragole, L-carvone, methyl eugenol, and pinomaridiene in wood. The method of the present application can measure the olfactory thresholds of the above-mentioned odor substances.

[0210] Moreover, there are no standard samples available for purchase on the market for α-borneol, trans-hinokitiol and pinamardiene, making it impossible to detect the olfactory threshold of α-borneol, trans-hinokitiol and pinamardiene in wood.

[0211] Comparison of three sample preparation methods:

[0212] Two types of wood, Chinese fir with a pronounced odor and poplar with a less odor, were selected to compare the capture of odorous substances by three pretreatment methods: dynamic headspace method, VOC chamber method and headspace-solid phase microextraction method. The results are listed in Tables 7 and 8.

[0213] Among them, 13 odor compounds were identified in Chinese fir using the dynamic headspace method, including 8 terpenes and 5 alcohols. A total of 6 odor compounds were identified using the VOC environmental chamber method, including 3 terpenes, 1 alcohol, 1 aldehyde and 1 alkane. A total of 12 odor compounds were identified using the headspace-solid phase microextraction method, including 9 terpenes, 2 alcohols and 1 ester.

[0214] Five odor compounds were identified in poplar wood using dynamic headspace method, including two terpenes, two aldehydes and one alcohol. Two odor compounds were identified using VOC chamber method, including one acid and one ester. No odor compounds were detected using headspace-solid phase microextraction method.

[0215] Table 7 Odor compounds of Chinese fir measured by three pretreatment methods

[0216]

[0217] Note: “-” means not detected.

[0218] Table 8 Odor compounds of poplar wood measured by three pretreatment methods

[0219]

[0220] Note: “-” means not detected.

[0221] By comparing the test results of fir and poplar, it can be seen that for fir with obvious odor and poplar with inconspicuous odor, the samples treated by dynamic headspace method can detect more odor substances. The headspace-solid phase microextraction method has a good analytical effect for samples with strong odor, but it is difficult to collect odor substances for samples with weak odor, that is, the headspace-solid phase microextraction method is not suitable for the threshold determination of samples with weak odor. The VOC environmental chamber method can detect odor substances for samples with obvious and inconspicuous odor, but the number is small. It can be seen that the dynamic headspace method is better among the three pretreatment methods. At the same time, there are differences in the odor compounds detected by the three pretreatment methods. For example, D-limonene in fir is only detected in the dynamic headspace method pretreatment, β-curcumene in fir is only detected in the headspace-solid phase microextraction method pretreatment, and terpinene-4-ol in fir is only detected in the VOC environmental chamber method pretreatment. It can be seen that the three methods can complement each other in detecting odor compounds.

[0222] In summary, by using the odor threshold determination method of the present invention, the accuracy of the odor threshold of the odor substance determined is improved, and the judgment of the odor substance will not be affected. In addition, in the process of determining the odor threshold of the odor substance, the detected odor substance is compared with the data in the NIST17.0 database to achieve qualitative detection of the odor substance, so that the qualitative detection of the odor substance can be achieved without configuring a standard sample.

[0223] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for determining the olfactory threshold of odor substances in artificial boards, characterized in that: include: Step 1: Prepare test sample; Step 2: Pre-treat the test sample and collect the mixed odor substances in the test sample; Step 3: Separate the mixed odor substances by gas chromatography, and send the separated single odor substances to the mass spectrometer for qualitative analysis of the odor substances; Step 4: While completing the qualitative analysis of the odor substance, use carrier gas to transport the odor substance to the olfactometer for artificial olfaction, adjust the split ratio at the injection port, and measure the olfactory threshold of each odor substance.

2. The method according to claim 1, characterized in that: In step 2, the test sample is pre-treated by a dynamic headspace method, a VOC environmental chamber method or a headspace-solid phase microextraction method to collect mixed odor substances in the test sample.

3. The method according to claim 2, characterized in that: The dynamic headspace method conditions include: incubation temperature: 50-65°C, incubation time: 25-35min, shaking speed: 450-550rpm, capture volume: 1L, capture flow: 60-90ml / min, adsorption trap temperature: 25-35°C, dry blowing volume: 600mL, dry blowing flow: 25-35mL / min, adsorption trap temperature during dry blowing: 25-35°C; Thermal desorption conditions: heating rate: 150-220℃ / min, final temperature: 250-270℃, holding time: 4-6min, transfer line temperature: 250-270℃; Cold trap conditions: initial temperature: -50°C, heating rate: 5-15°C / S, final temperature: 250-270°C, holding time: 4-6min; The conditions of the VOC environmental chamber method include: VOC chamber test conditions: VOC chamber temperature: 22.5-23.5℃, VOC chamber relative humidity: 42-48%, load rate: 0.98-1.02m 2 / m 3 , air replacement rate: 0.95-1.05h -1 , air velocity on sample surface: 0.95-1.05m / s; Air sampling conditions: start sampling time: 70-74h after the start of the test; sampling flow rate: 100-500mL / min; sampling time: 12-60min; The thermal desorption conditions and cold trap conditions are the same as those in the dynamic headspace method; The headspace-solid phase microextraction conditions include: Extraction conditions: extraction head: DVB-CAR-PDMS; extraction adsorption time: 15-60min, extraction temperature 50-100℃, desorption time 3-5min.

4. The method according to claim 1, characterized in that In step 3, it includes: S301: Separating mixed odor substances by gas chromatography, and diverting and transporting the separated single odor substances to a mass spectrometer detection location; S302: Obtain a mass spectrum of a single odor substance using mass spectrometry detection technology, and compare the mass spectrum of the odor substance with material data in a mass spectrometry library to determine the chemical composition of the odor substance.

5. The method according to claim 4, characterized in that In the step S301, when the dynamic headspace method or the VOC environmental chamber method is used to pre-treat the sample, the gas chromatography analysis conditions are: chromatographic column: DM-TVOC quartz capillary chromatographic column (50m×0.32mm×1μm) or a similar model chromatographic column; injection port temperature: 240-260°C; carrier gas is helium; flow rate: 1.5-1.6mL / min; heating program: initial temperature is 40-60°C, maintained for 1-3min, heated to 110-125°C at a rate of 5-15°C / min, maintained for 5-15min; then heated to 150-170°C at a rate of 4-6°C / min, maintained for 5-10min; heated to 180-220°C at a rate of 4-6°C / min, maintained for 5-15min; finally heated to 240-260°C at a rate of 4-6°C / min, maintained for 4-6min; When the headspace-solid phase microextraction method is used for pretreatment of the sample, the gas chromatography analysis conditions are: chromatographic column: DB-624 quartz capillary chromatographic column or similar model chromatographic column; injection port temperature: 240-260°C; carrier gas is helium; flow rate: 1.0mL / min; program temperature conditions are: starting temperature is 40-60°C, maintained for 1-3min, heated to 150-160°C at a rate of 5-20°C / min, maintained for 3-10min; then heated to 180-200°C at a rate of 1-10°C / min, maintained for 5-10min; finally heated to 230-260°C at a rate of 5-15°C / min and maintained for 10-15min; Among them, in the gas chromatography separation stage, the collected samples are split or not split when entering the gas chromatograph; In step S302, the mass spectrometry analysis conditions are: interface temperature of 260-300°C, quadrupole temperature of 140-160°C, EI ion source temperature of 220-240°C, electron energy of 60-80 eV, and mass scanning range of 45-550 m / z.

6. The method according to claim 4, characterized in that In step S302, a mass spectrum of a single odor substance is obtained by gas chromatography-mass spectrometry, and the mass spectrum of the odor substance is compared with the material data in the mass spectrum library. For odor substances with a similarity of not less than 85%, the chemical composition of the odor substance is determined based on the material mass spectrum fragment data in the mass spectrum library.

7. The method according to claim 1, characterized in that In step 4, it includes: S401: while completing the qualitative analysis of the odor substance, using a carrier gas to transport the odor substance to an olfactometer for artificial olfaction to obtain the odor category and odor intensity of the odor substance; S402: adjusting the split ratio of the sample when it enters the gas chromatograph to obtain the minimum odor intensity of the odor substance; S403: When the odor intensity of the odor substance is the lowest, the concentration of the odor substance is detected and obtained, and the concentration is used as the odor threshold of the odor substance.

8. The method according to claim 7, characterized in that In the step S401, after the sample is separated by the chromatographic column, it is split by a valve, with one part entering the olfaction port of the olfactometer and the other part entering the mass spectrometer; When the dynamic headspace method and the VOC environmental chamber method are used for pretreatment of the sample, the ratio of the flow rate entering the olfactory port to the flow rate entering the mass spectrometer end is adjusted to 1:1, and based on the length and inner diameter of the chromatographic column, the length of the empty column connected to the mass spectrometer end and the olfactory end after the three-way valve is determined; wherein, the empty columns of the olfactory and mass spectrometer are connected to the three-way valve, and the tail pressure of the chromatographic column is adjusted to 2.9-3.0PSI; When the headspace-solid phase microextraction method is used for pretreatment of the sample, the ratio of the flow rate entering the olfactory port to the flow rate entering the mass spectrometer port is adjusted to 1:1 or 7:3, and the length of the empty column connected to the mass spectrometer port and the olfactory port after the four-way valve is determined based on the length and inner diameter of the chromatographic column; In step S402, other parameters of the instrument are kept unchanged, and the split ratio is gradually increased; Among them, the split ratios are: no split, 15:1, 25:1, 30:1, 50:1, 75:1, 80:1, 90:1, 95:1, 100:1, and 200:

1.

9. The olfactory threshold of the odorous substance of the board obtained by using the method for determining the odorous threshold of the odorous substance of the artificial board according to any one of claims 1 to 8; in, The board material includes artificial board and raw materials thereof.

10. The olfactory threshold according to claim 9, comprising the olfactory threshold of terpenes in radiata pine and the olfactory threshold of terpenes in masson pine; in, The olfactory thresholds of terpenes in radiata pine include: Among them, the olfactory thresholds of terpenes in Masson pine include:

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