Method for identifying waxy unsaturated components of emerald based on infrared spectrum

Abstract

The invention relates to a method for identifying waxy unsaturated components of emerald based on infrared spectroscopy, and belongs to the technical field of emerald detection. Aiming at the problem that natural wax is misjudged to be manually treated according to the GB / T 16553-2017 standard, the method comprises the following steps: performing transmission absorption scanning on an old pit seed jade sample through a Fourier transform infrared spectrometer, detecting acromion form absorption peaks at 3035 + / -5cm <-1 > and 3065 + / -5cm <-1 >, and distinguishing natural solid wax oil from glue injection resin glue by combining with a threshold value of which the unsaturated hydrocarbon content is lower than 10%. Meanwhile, frequency doubling / combined frequency vibration peaks (4618 + / -10 cm <-1 >, 4527 + / -10 cm <-1 > and the like) and stretching vibration peaks (2598 + / -10 cm <-1 >, 2427 + / -10 cm <-1 >) of hydroxyl or carboxylic acid O-H bonds are used as auxiliary criteria, and a multi-parameter joint judgment model is established. According to the method, the peak form is combined with the content threshold value for the first time, the problem of false detection caused by overlapping of infrared characteristics of natural wax and resin adhesive is solved, and a scientific basis is provided for the nature of the wax in the old-pit jadeite.

Description

Technical Field

[0001] The present invention relates to the technical field of jadeite detection, and in particular to an identification method for waxy unsaturated components of old pit jadeite based on infrared spectroscopy. Background Art

[0002] Jadeite, a core variety of jade jewelry, has its market value and consumer rights directly impacted by the identification of its naturalness and treatment processes. Old pit seed jadeite often contains a natural solid wax due to long-term geological processes. Its formation is related to surface weathering and mineral penetration, and is a natural mineralization characteristic. However, the current national standard GB / T 16553-2017, "Jewelry and Jade Identification," has limitations in determining the presence of organic matter in jadeite. It implicitly attributes hydrocarbons or oxygen-containing organic matter detected by infrared spectroscopy to artificial wax infiltration, glue injection, or dyeing, leading to the misidentification of naturally waxy old pit jadeite as artificially treated.

[0003] Although traditional infrared spectroscopy identification technology can identify the type of organic matter (such as wax, resin glue, etc.), natural wax and artificial resin glue (such as epoxy resin) have different wavelengths at 3035cm -1 There are characteristic peaks of CH bond unsaturated hydrocarbons near 3065cm-1 and 3065cm-1, and conventional methods only rely on the position of the absorption peak for qualitative analysis, ignoring the peak morphology (shoulder peak and sharp peak) and the quantitative difference of the unsaturated component content. In addition, the hydroxyl and carboxylic acid functional groups in natural wax (such as 4618cm-1, 4527cm-1) -1 The OH bond overtone vibration peak at (1 / 2) was not included in the auxiliary criterion system, resulting in insufficient utilization of characteristic information.

[0004] Existing technical deficiencies directly lead to two types of industry problems: First, natural old pit jadeite is mistakenly identified as treated due to the presence of wax, damaging its collectible value and market liquidity. Second, artificially injected jadeite, due to its infrared characteristics partially overlapping with natural wax, may evade regulation and disrupt market order. Therefore, it is urgent to establish a technical solution based on the combined analysis of multiple parameters of infrared spectroscopy. Through the comprehensive analysis of peak position, peak shape, content threshold, and auxiliary absorption peaks, it can accurately distinguish natural wax from artificial resin glue. This will fill the technical gaps of standards and testing methods and support the scientific and impartial nature of jadeite identification. Summary of the Invention

[0005] In order to solve the problems of the prior art, the present invention provides an identification method for waxy unsaturated components of old pit jade based on infrared spectroscopy.

[0006] In order to solve the above technical problems, the present invention is achieved through the following technical solutions: In the first aspect, a method for identifying waxy unsaturated components of old pit jadeite based on infrared spectroscopy comprises the following steps:

[0007] S1: Take a sample of old pit seed jadeite and clean the surface;

[0008] S2: Use a Fourier transform infrared spectrometer to scan the sample using the transmission absorption method to obtain the transmission absorption spectrum;

[0009] S3: Check whether the infrared spectrum is within 3035±5cm -1 and 3065±5cm -1 There is an absorption peak with a shoulder shape at

[0010] S4: Based on the presence of the shoulder peak in step S3, it is determined that unsaturated hydrocarbon components exist in the solid waxy petroleum of the old pit seed material jadeite.

[0011] In this application, by detecting 3035±5cm -1 and 3065±5cm -1 The absorption peak at 4618±10cm is a broad and gentle shoulder peak, and combined with the characteristic of unsaturated hydrocarbon content less than 10%, it can clearly distinguish natural solid wax oil from injection resin glue (unsaturated hydrocarbon content is 100%, the corresponding absorption peak is a sharp peak), which effectively solves the misjudgment problem caused by the similar infrared characteristics of wax and resin glue in traditional detection. -1 、4527±10cm -1 Using the hydroxyl / carboxylic acid OH bond vibration absorption peak as an auxiliary judgment basis, it can accurately identify natural jadeite that has not been treated with wax infiltration, glue injection, or dyeing. Its core value lies in revising the GB / T16553-2017 standard's judgment logic for the presence of organic matter in jadeite. By establishing a spectral evidence chain for the natural nature of wax, it provides a scientific basis for determining the natural origin of organic matter in old pit seed jadeite, thereby avoiding the misidentification of natural wax oil as a product of artificial treatment, significantly improving the technical reliability and market standardization of jadeite identification.

[0012] In a specific embodiment of the first aspect, the content of the unsaturated hydrocarbon component is less than 10%, and the intensity of the shoulder peak is positively correlated with the content of the unsaturated component.

[0013] In a specific embodiment of the first aspect, at least one of the following characteristic absorption peaks is also present in the infrared spectrum:

[0014] 4618±10cm -1 、4527±10cm -1 、4053±10cm -1 The hydroxyl or carboxylic acid OH bond overtone / combination frequency vibration absorption peak at

[0015] 2598±10cm -1 、2427±10cm -1 The stretching vibration absorption peak of the hydroxyl or carboxylic acid OH bond at .

[0016] In a specific embodiment of the first aspect, the shape of the shoulder peak is a wide and gentle shoulder, which is different from the sharp peak shape of the resin glue in the glue-injected jade.

[0017] In a specific embodiment of the first aspect, the old pit seed material jadeite sample is a natural raw stone, a windowed raw stone or a peeled raw stone that has not been artificially infiltrated with wax, injected with glue or dyed.

[0018] In a specific embodiment of the first aspect, the method is used to distinguish the natural solid wax oil of old pit seed jade from the resin glue of injection-treated jade, specifically based on:

[0019] The unsaturated component content of natural solid wax oil is less than 10%, and 3035±5cm -1 、3065±5cm -1 The acromion;

[0020] The unsaturated component content of the injection resin is 100%, and 3035±5cm -1 、3065±5cm -1 There is a sharp peak.

[0021] In the second aspect, a Fourier transform infrared spectrometer system for identifying waxy unsaturated components of old pit jadeite based on infrared spectroscopy includes a transmission absorption accessory and is configured to detect 3035±5cm -1 and 3065±5cm -1 The absorption peak has a shoulder shape at .

[0022] Thirdly, an application of a method for identifying unsaturated wax components in old pit jadeite based on infrared spectroscopy is used to correct the misjudgment of organic matter contained in jadeite in the GB / T 16553-2017 standard and to confirm the naturalness of the solid wax oil in old pit seed jadeite.

[0023] The beneficial effects of the present invention are:

[0024] 1. Pass detection 3035±5cm -1 and 3065±5cm -1 The absorption peak with a broad and gentle shoulder shape at the bottom of the jadeite was combined with the threshold value of unsaturated hydrocarbon content below 10%. For the first time, a clear spectral criterion for distinguishing natural solid wax oil from injection resin glue was established (the latter has an unsaturated hydrocarbon content of 100% and a sharp absorption peak). This solved the problem of misjudgment caused by the overlapping characteristic peaks of the two types of organic matter in traditional infrared spectroscopy. In view of the limitation of GB / T 16553-2017 that directly classifies organic matter in jadeite as artificial treatment, the infrared characteristics of natural wax oil (such as the overtone / combination frequency vibration peak of hydroxyl / carboxylic acid OH bond at 4618±10cm -1 、4527±10cm -1etc.), providing scientific evidence for the presence of natural wax and avoiding misjudging untreated old pit seed jadeite as injected or dyed products.

[0025] 2. Through the joint analysis of multi-band absorption peaks (such as 2598±10cm -1 , the OH bond stretching vibration peak at 2427±10cm-1), which enhances the data support for the judgment of the naturalness of the wax and reduces the risk of false detection of a single characteristic peak; based on the Fourier transform infrared spectrometer system's recognition ability of the shoulder peak morphology, it standardizes the spectral comparison method of natural wax and resin glue, provides reproducible operating standards for laboratory identification, and promotes the uniformity of jade detection technology and market compliance; by confirming the natural origin of the solid wax oil in old pit seed jade, it provides technical endorsement for the identification of untreated jade, effectively maintains the market reputation of natural jade, and curbs the behavior of artificially processed jade as good quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the infrared transmission absorption spectrum of the old pit seed material rough stone one of the present invention.

[0027] Figure 2 This is the infrared transmission absorption spectrum of the old pit seed material rough stone 2 of the present invention.

[0028] Figure 3 This is a diagram of the infrared transmission and absorption spectrum of the semi-finished product three of the old pit seed material rough stone of the present invention.

[0029] Figure 4 This is the second figure of the infrared transmission absorption spectrum of the semi-finished product three of the old pit seed material rough stone of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] like Figures 1 to 4 The shown method for identifying waxy unsaturated components of old pit jadeite based on infrared spectroscopy.

[0032] 1. Clean the raw stone sample of the old pit seed material with distilled water or alcohol.

[0033] 2 Using a Fourier transform infrared spectrometer equipped with a transmission absorption accessory,

[0034] 3. Infrared scanning of the sample to obtain infrared transmission, absorption and scattering spectra.

[0035] 4 Based on the positions of the two peaks at 3035±5 and 3065±5 on the infrared spectrum and their broad shoulder shape, it was determined that unsaturated hydrocarbon components [UH, or "Ahai"] existed in the solid long-chain waxy petroleum mainly composed of hydrocarbons.

[0036] Figure 1 The infrared transmission absorption spectrum of the Laokeng seed material raw stone shows strong absorption peaks in the shape of spikes at wavenumbers 4621, 4059, 2615, and 2520, and weak absorption peaks in the shape of shoulders at wavenumbers 3035 and 3065. Because the intensity is too weak, it is not marked in the figure, indicating that the content of unsaturated components causing the weak peaks at 3035 and 3065 is very low.

[0037] Figure 2 The infrared transmission absorption spectrum of the second Laokeng seed material rough stone shows strong absorption peaks in the form of spikes at wavenumbers 4680, 4618, 4055, 2598, and 2427, and weak absorption peaks in the form of shoulders at wavenumbers 3032 and 3060. The intensities of the two shoulder peaks at 3032 and 3060 are very weak, indicating that the content of the unsaturated components that cause the weak peaks at 3025 and 3060 is very low.

[0038] Figure 3 The infrared transmission absorption spectrum of the Laokeng seed material semi-finished product No. 3 shows strong absorption peaks in the form of spikes at wavenumbers 4611, 4527, 4053, 2598, and 2427, as well as weak absorption peaks in the form of shoulders at wavenumbers 3031 and 3064. The intensities of the two shoulder peaks at 3031 and 3064 are very weak, indicating that the content of the unsaturated components that cause the weak peaks at 3031 and 3064 is very low.

[0039] Figure 4 The infrared transmission absorption spectrum of the Laokeng seed material semi-finished product No. 3 shows strong absorption peaks at wavenumbers 4608, 4531, 4052, 2595, and 2427, as well as weak absorption peaks at wavenumbers 3031 and 3062. The intensities of the two shoulder peaks at 3031 and 3062 are very weak, indicating that the content of the unsaturated component causing the weak peaks at 3031 and 3062 is very low.

[0040] The transmission absorption infrared spectra of the Laokeng seed material raw stone both show two weak peaks at 3035±5 and 3065±5, with a broad and gentle shoulder shape, rather than the sharp peak shape of resin. In addition, the Laokeng seed material raw stone itself has not undergone any human wax infiltration or glue injection treatment. Therefore, it can be determined that these two peaks are not resin, but unsaturated hydrocarbons (unsaturated hydrocarbons) naturally existing in solid waxy petroleum. Liquid petroleum usually contains trace amounts of unsaturated components, mainly referring to hydrocarbon compounds containing carbon-carbon double bonds (C=C) or carbon-carbon triple bonds (C≡C), including olefins, dienes, alkynes, aromatics, etc. These components are chemically active and easily undergo addition, polymerization and other reactions. Similarly, solid long-chain waxy petroleum usually contains unsaturated components, such as solid waxy petroleum in shale, or shale oil, which usually contains unsaturated components.

[0041] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 , near infrared region 4618, 4527, 4053 cm -1 Several strong absorption peaks nearby are all the double frequency or combined frequency vibration absorption of hydroxyl or carboxylic acid OH chemical bonds; low frequency region 2598, 2427cm -1 Several strong absorption peaks nearby are also the stretching vibration absorption of hydroxyl or carboxylic acid OH chemical bonds.

[0042] These series of hydroxyl peaks, which appear simultaneously with unsaturated components, indicate that the solid waxy petroleum in the raw Laokeng seed material is formed by the degradation of microbial organic macromolecules, which penetrated the jade's capillary pores and ice cracks with water in a surface environment, under the geothermal and geo-pressure conditions of the burial environment. Since microbial degradation primarily involves DNA and RNA molecules, incomplete degradation under the geothermal and geo-pressure conditions of the burial environment leaves behind components such as olefins, dienes, alkynes, and aromatics. These components all possess unsaturated chemical bonds, and due to their electrical imbalance, the solid waxy petroleum becomes polar, which then adsorbs water, a polar molecule with similar electrical imbalance. This explains the high concentration of adsorbed water in the solid waxy petroleum in Laokeng jade, which manifests as strong, sharp absorption peaks at wavenumbers 4611, 4527, 4053, 2598, and 2427 in the infrared spectrum.

[0043] The unsaturated components in the waxy petroleum in the old pit seed material jade have unsaturated chemical bonds. Due to the electrical imbalance, the solid petroleum becomes a polar molecule. These components have active chemical properties and are prone to addition, polymerization and other reactions. They are reactive, that is, they are easy to react. For example, alkenes and alkynes are prone to addition (such as hydrogenation, halogenation) reactions, polymerization reactions (such as polyethylene, polypropylene), or oxidation reactions, etc.

[0044] The applicant's discovery of unsaturated hydrocarbon components within the solid waxy petroleum present in raw Laokeng seed jadeite is a first for the international academic community. This discovery can help accurately determine the properties and types of petroleum present in Laokeng jadeite using infrared spectroscopy, and help accurately distinguish it from the resinous gums found in bleached, injected, and dyed jadeite. This discovery and invention will unravel the scientific mystery of the gloss and oiliness of Laokeng jadeite, and contribute significantly to the market promotion, restoration, and enhancement of the value of Laokeng jadeite.

[0045] In summary, the key technical points of the present invention are:

[0046] The present invention, using infrared spectroscopy transmission absorption method, is the first scientific discovery in the international academic community that trace amounts of unsaturated components exist in the naturally occurring solid waxy petroleum in old pit seed material jadeite rough stones. Therefore, a method for identifying the presence of unsaturated components in the naturally occurring solid waxy petroleum in old pit seed material rough stones has been invented. The key technical points to be protected are:

[0047] 1) Based on the presence of two shoulder peaks at wavenumbers 3035±5 and 3065±5 in the transmission absorption infrared spectrum, it was determined that solid waxy petroleum, mainly hydrocarbon components, existed in the Laokeng jadeite rough stone. In addition, it was solid long-chain waxy petroleum, and the waxy petroleum contained unsaturated components.

[0048] 2) Based on the presence of two weak shoulder peaks at wavenumbers 3035±5 and 3065±5 in the transmission absorption infrared spectrum, it was determined that the content of unsaturated components in the waxy petroleum in the Laokeng jadeite raw stone was a trace amount of less than 10%;

[0049] 3) The transmission absorption infrared spectrum of the raw jadeite from the old pit confirms the existence of unsaturated components. The supporting evidence is usually in the near infrared region at 4618, 4527, and 4053 cm -1 There are several strong absorption peaks nearby, which are the double frequency or combined frequency vibration absorption of hydroxyl or carboxylic acid OH chemical bonds; at the same time, in the low frequency region 2598, 2427cm -1 There are also several strong absorption peaks nearby, which are also the stretching vibration absorption peaks of hydroxyl or carboxylic acid OH chemical bonds;

[0050] 4) Confirm that the solid waxy petroleum in the old pit seed material is different from the resin glue in the glue-injected jadeite;

[0051] 5) It is confirmed that the presence of solid waxy petroleum is the source of the old pit seed material's glossy, luster, beautiful oiliness, and crystal-like agility. It is accepted by the jewelry industry and is not artificially filled with resin glue through strong acid and alkali corrosion and bleaching. The unsaturated components in it have relatively active chemical properties and are prone to addition, polymerization, oxidation and other reactions. They are reactive, that is, highly reactive. The reactivity causes the old pit seed material jade to undergo a series of magical changes in light color and water head in the surface environment and during human collection, circulation and use.

[0052] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. The identification method of waxy unsaturated components of Laokeng jadeite based on infrared spectroscopy is characterized by: The following steps are involved: S1: Take a sample of old pit seed jadeite and clean the surface; S2: Use a Fourier transform infrared spectrometer to scan the sample using the transmission absorption method to obtain the transmission absorption spectrum; S3: Check whether the infrared spectrum is within 3035±5cm -1 and 3065±5cm -1 There is an absorption peak with a shoulder shape at S4: Based on the presence of the shoulder peak in step S3, it is determined that unsaturated hydrocarbon components exist in the solid waxy petroleum of the old pit seed material jadeite.

2. The method for identifying waxy unsaturated components of old pit jadeite based on infrared spectroscopy according to claim 1, characterized in that: The content of the unsaturated hydrocarbon components is less than 10%, and the intensity of the shoulder peak is positively correlated with the content of the unsaturated components.

3. The method for identifying waxy unsaturated components in old pit jadeite based on infrared spectroscopy according to claim 1, characterized in that: The infrared spectrum also contains at least one of the following characteristic absorption peaks: 4618±10cm -1 、4527±10cm -1 、4053±10cm -1 The hydroxyl or carboxylic acid OH bond overtone / combination frequency vibration absorption peak at 2598±10cm -1 、2427±10cm -1 The stretching vibration absorption peak of the hydroxyl or carboxylic acid OH bond at .

4. The method for identifying waxy unsaturated components of old pit jadeite based on infrared spectroscopy according to claim 1, characterized in that: The shape of the shoulder peak is a wide and gentle shoulder, which is different from the sharp peak shape of the resin glue in the glue-injected jadeite.

5. The method for identifying waxy unsaturated components of old pit jadeite based on infrared spectroscopy according to claim 1, characterized in that: The old pit seed material jade samples are natural raw stones, windowed raw stones or peeled raw stones that have not been artificially waxed, injected with glue or dyed.

6. The method for identifying waxy unsaturated components in old pit jadeite based on infrared spectroscopy according to claim 1, characterized in that: The method is used to distinguish the natural solid wax oil of old pit seed jadeite from the resin glue of injected jadeite. The specific basis is: The unsaturated component content of natural solid wax oil is less than 10%, and 3035±5cm -1 、3065±5cm -1 The acromion; The unsaturated component content of the injection resin is 100%, and 3035±5cm -1 、3065±5cm -1 There is a sharp peak.

7. A Fourier transform infrared spectrometer system for identifying waxy unsaturated components in Laokeng jadeite based on infrared spectroscopy, characterized by: Includes transmission absorption accessory and is configured to detect 3035±5cm -1 and 3065±5cm -1 The absorption peak has a shoulder shape at .

8. An application of a method for identifying waxy unsaturated components in old pit jadeite based on infrared spectroscopy, characterized in that: Used to correct the misjudgment in GB / T 16553-2017 standard about the organic matter contained in jadeite, and to confirm the naturalness of the solid wax oil in old pit seed material jadeite.

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