阅读说明：本技术 利用气相色谱质谱联用技术对含瘿瘤木材进行鉴定的方法 (Method for identifying gall-containing wood by gas chromatography-mass spectrometry ) 是由 朱涛 卓金勋 张秋龙 林龙 郑承镇 彭建泉 于 2019-10-24 设计创作，主要内容包括：本发明公开利用气相色谱质谱联用技术对具特殊性气味含瘿瘤木材进行鉴定的方法,包括以下步骤：第一步,使用去离子水将降香黄檀和大果紫檀试验材料表面灰尘去除干净,气干后用带锯机锯成小块置于粉碎机进行粉碎,筛选40～60目的木粉作为待测样品,放置于干燥器中遮光保存备用；第二步,将待测样品粉末在80℃条件下加热孵化30min；第三步,分别将含瘿瘤的降香黄檀和大果紫檀的待测样品置于顶空采样瓶后,置于气相色谱质谱联用仪上样分析,初始温度50℃,保留时间1min后以10℃/min升温至300℃,保持10min。对获得样品总离子流图进行分析,获取样品各自主要特征峰及其对应的保留时间,并作为其主要识别特征。本发明所提供的采用顶空直接进样方式,结合GC-MS技术,对含瘤疤降香黄檀木材进行识别和鉴定,解决传统识别方法对含瘤疤降香黄檀木材识别鉴定束手无策的问题。(The invention discloses a method for identifying gall-containing wood with special odor by using a gas chromatography-mass spectrometry combined technology, which comprises the following steps: firstly, removing dust on the surfaces of test materials of dalbergia odorifera and pterocarpus macrocarpus by using deionized water, after air drying, sawing into small blocks by using a band saw, putting the small blocks into a crusher for crushing, screening wood powder of 40-60 meshes as a sample to be detected, and putting the sample into a dryer for shading and storing for later use; secondly, heating and incubating the sample powder to be tested for 30min at the temperature of 80 ℃; and thirdly, respectively placing the samples to be tested of the rosewood and the pterocarpus macrocarpus containing galls in a headspace sampling bottle, placing the samples in a gas chromatography-mass spectrometer for sample loading analysis, wherein the initial temperature is 50 ℃, the retention time is 1min, then the temperature is increased to 300 ℃ at the speed of 10 ℃/min, and the temperature is kept for 10 min. And analyzing the obtained sample total ion flow graph, and obtaining respective main characteristic peaks and corresponding retention time of the samples as main identification characteristics of the samples. The method provided by the invention adopts a headspace direct sample introduction mode, combines a GC-MS technology, identifies and identifies the dalbergia odorifera wood containing the scars, and solves the problem that the traditional identification method cannot identify and identify the dalbergia odorifera wood containing the scars.)

1. The method for identifying the gall-containing wood by using the gas chromatography-mass spectrometry technology is characterized by comprising the following steps of: the method comprises the following steps:

firstly, removing dust on the surfaces of test materials of dalbergia odorifera and pterocarpus macrocarpus by using deionized water, after air drying, sawing into small blocks by using a band saw, putting the small blocks into a crusher for crushing, screening wood powder of 40-60 meshes as a sample to be detected, and putting the sample into a dryer for shading and storing for later use;

secondly, heating and incubating the sample powder to be tested for 30min at the temperature of 80 ℃;

thirdly, respectively placing samples to be tested of rosewood and pterocarpus macrocarpus containing galls in a headspace sampling bottle, placing the samples in a gas chromatography-mass spectrometer for sample loading analysis, wherein the initial temperature is 50 ℃, the retention time is 1min, then heating to 300 ℃ at a speed of 10 ℃/min, and keeping for 10 min;

fourthly, acquiring and analyzing respective total ion flow diagrams to obtain respective main characteristic peaks and corresponding retention time, screening out peaks with stable peak appearance and relative peak areas larger than 1.0% in the respective retention time as respective identification characteristic peaks, and identifying and matching chemical components corresponding to the respective characteristic peaks through mass spectrum libraries NIST2017 and Wily10.0 to obtain respective characteristic chemical components;

and fifthly, repeatedly testing the sample powder of the dalbergia odorifera wood containing the gall to obtain the retention time of a relatively stable characteristic peak and a corresponding characteristic peak area thereof as main identification characteristics of the dalbergia odorifera wood, carrying out correlation and characteristic component comparison analysis on other wood to be tested and the other wood to be tested, and when the correlation coefficient is greater than 0.900 or the main chemical components of the other wood are consistent, determining that the dalbergia odorifera wood is the dalbergia odorifera wood containing the gall.

2. A method of identifying gall-bearing wood using gas chromatography mass spectrometry as claimed in claim 1, wherein: in the third step, the chromatographic conditions were active CP-Sil8CB as a separation column with dimensions 30m x 0.25mm x 0.50 μm, length x inner diameter x coating thickness; the carrier gas and the flow rate are respectively helium gas, 1.4 ml.min < -1 >; the injection port temperature is 280 ℃, the split ratio is 20: 1, and the injection amount is 1 mu L.

3. A method of identifying gall-bearing wood using gas chromatography mass spectrometry as claimed in claim 2, wherein: in the third step, the mass spectrometry condition is Scan mode Scan; the ion source scanning range 35-550 aum; the ion source temperature is 250 ℃; the transmission line temperature is 280 ℃; an ionization mode EI; electron energy 70 eV; the mass spectra libraries were NIST2017 and wiley10.0.

Technical Field

The invention relates to a method for identifying gall-containing wood by using a gas chromatography-mass spectrometry coupling technology, belonging to the technical field of wood identification.

Background

At present, a detection mechanism identifies wood species based on a traditional wood identification method, namely, macroscopic characteristics (quality, texture, color, smell and the like) and microcosmic structural characteristics (pipe hole characteristics, wood ray types, axial thin-wall tissue types and the like) of wood are observed and recorded, then related professional books are consulted and compared with a standard sample, so that identification of a wood sample to be detected is realized, and a corresponding wood inspection report is issued. With the continuous development of scientific technology, more and more new technologies are applied to wood identification. The gas chromatography-mass spectrometry combined technology has better separation and qualitative effects on the wood sample to be detected. In recent years, it has been applied to wood authentication.

The headspace direct sampling method is characterized in that a sample to be detected is directly placed in a headspace bottle without extraction pretreatment, the sample is directly subjected to sample loading analysis by adopting a GC-MS (gas chromatography-mass spectrometry) technology, an obtained total ion flow graph is analyzed, and the characteristic chemical components of the sample to be detected are determined according to the characteristic peak opposite area corresponding to retention time and mass spectrum library matching, so that the construction of the fingerprint of the sample to be detected is realized. The method has the characteristics of high detection efficiency and small loss of the sample to be detected. Researchers have implemented this technique to distinguish and identify Dalbergia odorifera and Dalbergia tonkinensis, Dalbergia cochinchinensis and Dalbergia microminiana (Dalbergia retusa). In recent years, a wood named as rosewood dye appears in the market, as the macroscopic structure and the microscopic structure of the wood are very similar to the rosewood sandalwood, the two cannot be distinguished accurately by the traditional wood identification method, researchers take a small amount of wood powder of the two, adopt ultrasonic extraction and combine GC-MS technology to realize correlation analysis of total ion flow diagrams obtained by the two, and further realize the distinction and identification of the two. The method belongs to an indirect introduction method and has the problem of complicated preparation of the sample at the early stage. For some non-redwood woods with characteristic odor (Phoebe spp. of the genus phyllus and Machilus spp.), researchers also use a headspace sampling mode to realize the distinction and identification of the two woods.

Dalbergia odorifera (Dalbergia odorifera) belongs to the wood of the rosewood family specified in the Redwood national standard GB/T18107, and is always favored by consumers due to its good appearance, excellent physical properties, scarce resources, and its inherent strong spicy flavor. In recent years, with the continuous decrease of resources, more and more dalbergia odorifera woods containing scabs are applied to the processing and production of wood artware, the woods containing the scabs are also called galls, and the scabs are mainly generated as the trees themselves generate lesions in the growth process of the trees and are the result of pathological hyperplasia of the trees. The large and small scars appear on the tree body, while the large scars appear on the root of the tree. The wood contains natural patterns formed by natural scabs, the grains are staggered and move in a cloud way, so that the appearance performance of the wood is obviously improved, the price is also increased, and accordingly, the market has the appearance similarity of bad customers and other tree species wood containing the scabs to counterfeit the wood so as to try for violence and seriously damage the benefits of consumers. The wood contains the scabs, the wood grains are staggered and distorted, wood appraisers cannot accurately find the three sections of the wood and cannot slice the wood, and the microscopic structural characteristics of the wood are observed and recorded under a microscope, so the wood appraisers cannot appraise the wood by the traditional wood appraising method, once a detection mechanism receives entrusted appraisal of the dalbergia odorifera wood containing the scabs, the detection mechanism is often unfamiliar with the restraint, and the detection mechanism needs to seek other new technologies to appraise the dalbergia odorifera wood.

Looking up relevant documents at home and abroad, more and more new technologies are applied to the identification of dalbergia odorifera wood at present. The rDNA-ITS sequences of dalbergia odorifera woods in different producing areas and allied species of the dalbergia odorifera woods are determined and subjected to differential analysis, theoretical technical support is provided for identification by using ITS barcode sequences, but the method is high in experimental cost and cannot be applied to actual detection at present. In addition, researchers also utilize near infrared spectroscopy (NIRS) to analyze chemical main components of 8 types of rosewood specified by national standards to identify the difference of the amygdalus comnnis from other woods, so that feasibility of applying the near infrared spectroscopy to wood identification is shown, but at present, the research is still in a scientific exploration stage, and a certain distance is left from practical application. The inventor of the patent identifies 9 rosewoods in 2013 by adopting two different sample introduction modes (namely an indirect introduction method and a direct introduction method) by adopting a GC-MS technology, and the result shows that the identification of the dalbergia odorifera wood can be realized by a headspace sampling mode, but the research does not research the dalbergia odorifera containing the tumor scar.

At present, the traditional wood identification method mainly identifies the wood by combining macroscopic and microscopic structural features of the wood. But grain distortion of gall-containing wood does not allow identification of such wood. At present, an identification method for gall-containing wood is not seen. The method is an indirect introduction method for normal wood based on gas chromatography-mass spectrometry technology, namely, firstly, a wood sample is extracted by different organic solvents, or an auxiliary extraction mode such as ultrasonic extraction is adopted, correlation analysis is carried out on an obtained total ion flow diagram by combining the organic wood extract with GC-MS technology, and then the difference and the identification of the two are realized. The method belongs to an indirect introduction method and has the problem of complicated preparation of the sample at the early stage. For some wood with characteristic odor and without gall (Phoebe spp. of the genus phoenix and Machilus spp.), researchers also used headspace sampling to distinguish and identify the wood.

The traditional method cannot identify the gall-containing wood according to the anatomical characteristics of the wood, because the texture of the wood is distorted, the three sections of the wood cannot be accurately found, and the three section structural characteristics cannot be used for identifying the wood. The sample introduction treatment by an indirect method needs different organic extraction solutions to carry out extraction pretreatment on the sample, and the time cost is increased. Meanwhile, because wood belongs to a natural polymer material and has complex chemical components, the obtained total ion flow graph is easy to have the condition of overlapping characteristic peaks, namely more than one characteristic peak is corresponding to the same retention time. The direct sample introduction mode is adopted, the incubation heating pretreatment is not carried out on the sample before sample introduction, the obtained peak time and the like are unstable, and the reliability and the accuracy of the experimental result are influenced.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the problems and the defects in the prior art, the invention provides the method for identifying the gall-containing wood, which has high identification accuracy, simple method and low cost.

The technical scheme is as follows: the method for identifying the gall-containing wood by using the gas chromatography-mass spectrometry technology is characterized by comprising the following steps of: the method comprises the following steps:

firstly, removing dust on the surfaces of test materials of dalbergia odorifera and pterocarpus macrocarpus by using deionized water, after air drying, sawing into small blocks by using a band saw, putting the small blocks into a crusher for crushing, screening wood powder of 40-60 meshes as a sample to be detected, and putting the sample into a dryer for shading and storing for later use;

secondly, heating and incubating the sample powder to be tested for 30min at the temperature of 80 ℃; the heating incubation is mainly used for volatilizing main volatile chemical components of the sample before sample introduction, so that the obtained result is more stable and reliable.

Thirdly, respectively placing samples to be tested of rosewood and pterocarpus macrocarpus containing galls in a headspace sampling bottle, placing the samples in a gas chromatography-mass spectrometer for sample loading analysis, wherein the initial temperature is 50 ℃, the retention time is 1min, then heating to 300 ℃ at a speed of 10 ℃/min, and keeping for 10 min;

fourthly, acquiring and analyzing respective total ion flow diagrams through chemical workstation analysis software of a gas chromatography-mass spectrometer to obtain respective main characteristic peaks and corresponding retention time, screening peaks which are stable in peak and have relative peak areas larger than 1.0% in the respective retention time as respective identification characteristic peaks, easily overlapping the characteristic peaks, treating the peaks as 2 characteristic peaks when the adjacent retention time is larger than 0.1min, and identifying and matching chemical components corresponding to the respective characteristic peaks through mass spectrum libraries NIST2017 and Wily10.0 to obtain respective characteristic chemical components if the peaks are the same;

and fifthly, repeatedly testing the sample powder of the rosewood containing the goiter to obtain the retention time of a relatively stable characteristic peak and a corresponding characteristic peak area thereof as a main identification characteristic of the sample powder, carrying out correlation and characteristic component comparison analysis on other wood to be detected and the other wood to be detected, and when the correlation coefficient is greater than 0.900 or the main chemical components of the wood are consistent, determining the wood to be the rosewood containing the goiter, wherein the method can realize the identification of the rosewood containing the goiter.

The invention further defines the technical scheme as follows: in the third step, the chromatographic conditions were the agent CP-Sil8CB as a separation column with dimensions 30m x 0.25mm x 0.50 μm, length x inner diameter x coating thickness; the carrier gas and the flow rate are respectively helium gas, 1.4 ml.min < -1 >; the injection port temperature is 280 ℃, the split ratio is 20: 1, and the injection amount is 1 mu L.

Preferably, in the third step, the mass spectrometry condition is Scan mode Scan; the ion source scanning range 35-550 aum; the ion source temperature is 250 ℃; the transmission line temperature is 280 ℃; an ionization mode EI; electron energy 70 eV; the mass spectra libraries were NIST2017 and wiley10.0.

Has the advantages that: compared with the prior art, the method provided by the invention adopts a headspace direct sample injection mode, combines a GC-MS technology, and carries out heating incubation pretreatment on the sample before sample injection, so that the main volatile components are volatilized and then subjected to sample injection analysis, the accuracy of the test result can be improved, and the chromatographic peak corresponding to the retention time is not easy to drift. The identification and identification of the dalbergia odorifera wood containing the scab can be realized, the problem that the traditional identification method is unfair to the identification and identification of the dalbergia odorifera wood containing the scab is solved, the related technology for identifying the dalbergia odorifera wood containing the scab by applying the GC-MS direct sampling technology is provided, the technical bottleneck of the identification and identification of the kind of wood is expected to be solved, and the powerful technical support is provided for the wood identification mechanism and the trade unit to quickly and accurately identify the kind of wood. The traditional identification method relying on the anatomical characteristics of the wood cannot identify the wood containing galls, the wood sample is heated and incubated before sample headspace sample injection, so that main characteristic chemical components of the wood sample are volatilized before sample injection, the accuracy of a result can be improved, and the identification of the wood can be quickly and efficiently realized by adopting the headspace sample injection method.

Drawings

FIG. 1 is a total ion flow diagram of Dalbergia odorifera containing goiter.

FIG. 2 is a total ion flow graph of a pterocarpus santalinus wood containing goiter.

FIG. 3 shows the results of cluster analysis of two batches of rosewood containing goiter and pterocarpus macrocarpus.

FIG. 4 is a finger print of rosewood and pterocarpus macrocarpus containing goiter.

Detailed Description

The invention is further elucidated with reference to the drawings and the embodiments.

A method for identifying gall-containing wood using gas chromatography-mass spectrometry as shown in fig. 1-4, comprising: the method comprises the following steps:

firstly, removing dust on the surfaces of test materials of dalbergia odorifera and pterocarpus macrocarpus by using deionized water, after air drying, sawing into small blocks by using a band saw, putting the small blocks into a crusher for crushing, screening wood powder of 40-60 meshes as a sample to be detected, and putting the sample into a dryer for shading and storing for later use;

secondly, heating and incubating the sample powder to be tested for 30min at the temperature of 80 ℃; the heating incubation is mainly used for volatilizing main volatile chemical components of the sample before sample introduction, so that the obtained result is more stable and reliable;

thirdly, respectively placing samples to be tested of rosewood and pterocarpus macrocarpus containing galls in a headspace sampling bottle, placing the samples in a gas chromatography-mass spectrometer for sample loading analysis, wherein the initial temperature is 50 ℃, the retention time is 1min, then heating to 300 ℃ at a speed of 10 ℃/min, and keeping for 10 min;

fourthly, acquiring and analyzing respective total ion flow diagrams through chemical workstation analysis software of the gas chromatography-mass spectrometer to obtain respective main characteristic peaks and corresponding retention time; screening peaks which are stable in peak appearance in respective retention time and have a relative peak area larger than 1.0% as respective identification characteristic peaks, easily overlapping the characteristic peaks, treating the peaks as 2 characteristic peaks when the adjacent retention time is larger than 0.1min, and otherwise, treating the peaks as the same characteristic peak; and simultaneously, identifying and matching the chemical components corresponding to the respective characteristic peaks through mass spectrum libraries NIST2017 and Wily10.0 to obtain the respective characteristic chemical components.

And fifthly, repeatedly testing the sample powder of the rosewood containing the goiter to obtain the retention time of a relatively stable characteristic peak and a corresponding characteristic peak area thereof as a main identification characteristic of the sample powder, carrying out correlation and characteristic component comparison analysis on other wood to be detected and the other wood to be detected, and when the correlation coefficient is greater than 0.900 or the main chemical components of the wood are consistent, determining the wood to be the rosewood containing the goiter, wherein the method can realize the identification of the rosewood containing the goiter.

The invention further defines the technical scheme as follows: in the third step, the chromatographic conditions are AglientCP-Sil 8CB as a separation column with dimensions 30m x 0.25mm x 0.50 μm, length x inner diameter x coating thickness; the carrier gas and the flow rate are respectively helium gas, 1.4 ml.min < -1 >; the injection port temperature is 280 ℃, the split ratio is 20: 1, and the injection amount is 1 mu L.

Preferably, in the third step, the mass spectrometry condition is Scan mode Scan; the ion source scanning range 35-550 aum; the ion source temperature is 250 ℃; the transmission line temperature is 280 ℃; an ionization mode EI; electron energy 70 eV; the mass spectra libraries were NIST2017 and wiley10.0.

In view of the special fragrance of dalbergia odorifera, identification of volatile odor chemical components of dalbergia odorifera containing the tumor scar can be realized based on a GC-MS technology headspace sampling method, and a specific chromatographic peak and chemical components of the dalbergia odorifera are found out and used as main identification characteristics of the dalbergia odorifera through analysis of the chromatographic peak and the characteristic chemical components of the dalbergia odorifera. The other chromatographic peaks and characteristic chemical components which are similar in appearance and simulate the wood can be compared with the other chromatographic peaks and the characteristic chemical components to realize the identification of the wood. Meanwhile, the ratio of all characteristic peak areas to the maximum chromatographic peak area can be used as a vertical coordinate, the retention time is used as a horizontal coordinate to establish a characteristic fingerprint spectrum of the dalbergia odorifera wood with the scabs, and finally the fingerprint spectrum of the sample to be detected is compared with the characteristic fingerprint spectrum, so that the identification of the dalbergia odorifera wood with the scabs can be realized. The method has important significance for solving the technical bottleneck of wood identification work, striking illegal vendors, maintaining the benefits of consumers and promoting the benign development of the wood product market.

Specific experimental data are shown in tables 1-5 below:

TABLE 1 summarization of the relative peak areas of Dalbergia odorifera Wood with goiter

Table Relative peak areas of Dalbergia odorifera

TABLE 2 summarization of the relative peak areas of Pterocarpus macrocarpus containing galls

Table 2 Relative peak areas of Pterocarpus macrocarpu

TABLE 3 correlation analysis of lignum Dalbergiae Odoriferae with goiter and lignum Pterocarpi macrocarpi

Table 3 Coefficient correlations between Dalbergia odorifera andPterocarpus macrocarpu with burl

TABLE 4 Main chemical composition of lignum Dalbergiae Odoriferae containing goiter

Table 4 Main chemical compositions of Dalbergia odorifera with burl

TABLE 5 Main chemical composition of Pterocarpus macrocarpus Wood containing goiter

Table 5 Main chemical compositions of Pterocarpus macrocarpu withburl

The embodiment is based on GC-MS technology, and adopts a headspace sampling mode to obtain a total ion flow graph of lignum Dalbergiae Odoriferae and lignum Dalbergiae Odoriferae containing goiter, wherein both woods have a group of characteristic peaks different from each other. The correlation of relative peak areas after the integration of the total ion flow graph of two kinds of gall-containing wood is analyzed, and the experimental result shows that the correlation coefficients of two batches of the same kind of wood are all larger than 0.900, but the correlation between different kinds of wood is not existed; the system clustering analysis result also obtains the same conclusion; the two types of wood also contain substantially different amounts and types of the major volatile chemicals. The results of the three analysis methods of correlation analysis, cluster analysis and characteristic component analysis are highly consistent, which shows that the method can realize the differentiation and identification of the gall-containing wood and solve the problem that the traditional wood dissection is difficult to identify the gall-containing wood. The foregoing is only a preferred embodiment of this invention and it should be noted that modifications can be made by those skilled in the art without departing from the principle of the invention and these modifications should also be considered as the protection scope of the invention.