A method for quantitatively analyzing hydrogen peroxide in wooden cultural relics

Abstract

The application discloses a method for quantitatively analyzing hydrogen peroxide in wooden cultural relics, and relates to the field of wooden cultural relic protection and analysis and detection. The method comprises the following steps: dividing a to-be-detected wooden cultural relic sample into multiple aliquots; performing differential pretreatment on different aliquots, so that the contribution of endogenous hydrogen peroxide and / or interfering substances in each sample to a final detection signal presents a calculable difference; extracting hydrogen peroxide from each pretreated aliquot to obtain a corresponding extract; respectively determining the apparent content of hydrogen peroxide in each extract; and based on the difference between the measured apparent contents, calculating the true content of endogenous hydrogen peroxide in the wooden cultural relic sample. The method for quantitatively analyzing hydrogen peroxide in wooden cultural relics can effectively overcome the interference of a complex matrix of wooden cultural relics, is simple and convenient to operate, accurate in quantification, does not need complex pretreatment, and is consistent with the requirements of cultural relic protection.

Description

Technical Field

[0001] This application relates to the field of conservation and analysis of wooden cultural relics, and in particular to a quantitative analysis method for hydrogen peroxide in wooden cultural relics. Background Technology

[0002] Wooden artifacts are an important part of human cultural heritage, carrying invaluable historical, artistic, and scientific value. However, during long-term preservation, wooden artifacts are prone to oxidation and aging due to environmental factors (such as light, temperature and humidity changes, and metal contaminants), leading to material deterioration and reduced strength, seriously threatening their permanent preservation. Hydrogen peroxide, as a key intermediate product of the photo-oxidation of lignocellulose and the Fenton reaction catalyzed by metal ions, is crucial for accurately determining its content. This is essential for assessing the degree of artifact deterioration, revealing degradation mechanisms, and developing scientific conservation and restoration strategies.

[0003] Currently, the main methods for detecting hydrogen peroxide include titration, chemiluminescence, fluorescence, and ultraviolet-visible spectrophotometry. Among these, the titanium salt colorimetric method is widely used due to its simplicity and readily available equipment. Its principle is based on the formation of a stable yellow complex between hydrogen peroxide and titanium salt in an acidic medium, which exhibits characteristic absorption at a wavelength of 415 nm.

[0004] However, the complexity of the wooden matrix of cultural relics poses a significant challenge to the accurate quantification of hydrogen peroxide. Specifically: First, the presence of transition metal ions such as iron / ferrous ions in the relics can catalyze the Fenton reaction throughout the detection process, causing variations in the hydrogen peroxide content of the target substance and resulting in systematically low readings. Second, these metal ions may also interfere with the normal color development of titanium salt colorimetric reagents through competitive complexation reactions, affecting detection sensitivity. Third, organic components such as lignin and extracts may generate non-specific background absorption at characteristic absorption wavelengths, leading to falsely high readings. Existing technologies struggle to overcome these opposing interferences simultaneously. Conventional blank correction or separation and purification methods cannot effectively distinguish and subtract this complex matrix effect formed by the superposition of multiple mechanisms, thus compromising the accuracy of the detection results.

[0005] To address the aforementioned issues, existing technologies largely focus on the detection of free hydrogen peroxide or employ cumbersome separation and purification steps to attempt to eliminate matrix interference. For example, solid-phase extraction and column chromatography are used to pre-separate the target analyte. However, these methods are often complex, time-consuming, and struggle to effectively distinguish and eliminate the specific matrix interferences mentioned above. Furthermore, the separation process can easily lead to the loss of the target analyte or introduce new errors. Therefore, developing a quantitative analysis method for hydrogen peroxide that can specifically overcome the complex matrix interference of wooden artifacts, is simple to operate, and yields accurate results has become an urgent technical problem to be solved in the scientific research and conservation practice of wooden artifacts. Summary of the Invention

[0006] This application discloses a quantitative analysis method for hydrogen peroxide in wooden artifacts, which solves the technical problems in the detection of hydrogen peroxide in wooden artifacts due to multiple matrix effects such as the decomposition of target substances by metal ions catalyzing the complex matrix, the interference of competitive complexation and color development, and the superposition of background absorption by organic components. These problems lead to the inability of conventional methods to effectively distinguish and eliminate interference, resulting in poor accuracy of detection results. Furthermore, existing separation and purification methods are cumbersome and prone to loss of target substances.

[0007] To solve the above problems, this application adopts the following technical solution: In a first aspect, embodiments of this application provide a method for the quantitative analysis of hydrogen peroxide in wooden artifacts, comprising the following steps: The wooden artifact sample to be tested was divided into multiple equal sub-samples; By performing differentiated pretreatment on samples of different equal divisions, the contribution of endogenous hydrogen peroxide and / or interfering substances in each sample to the final detection signal can be calculated differently. Hydrogen peroxide was extracted from each of the pretreated aliquots to obtain the corresponding extracts; The apparent content of hydrogen peroxide in each extract was determined; and based on the differences between the measured apparent contents, the true content of endogenous hydrogen peroxide in each extract was calculated.

[0008] The technical solutions adopted in the embodiments of this application can achieve the following beneficial effects: (1) The quantitative analysis method for hydrogen peroxide in wooden artifacts provided in this application involves dividing the wooden artifact samples into equal parts and performing differential pretreatment, thereby creating a calculable difference in the contribution of endogenous hydrogen peroxide and interfering substances to the detection signal. Simultaneously, this method eliminates the need for complex separation and purification of the target analyte, reducing the loss of endogenous hydrogen peroxide during extraction and avoiding secondary errors caused by additional separation steps. Furthermore, it eliminates the need for complex matrix correction models, simplifying the data processing flow while avoiding biases caused by matrix differences in traditional correction methods, significantly improving the accuracy and reliability of quantitative analysis.

[0009] (2) The quantitative analysis method for hydrogen peroxide in wooden cultural relics provided in this application has a scientific and well-organized process design. From sample division and differentiated pretreatment to hydrogen peroxide extraction, apparent content determination and actual content calculation, each operation is easy to standardize and control. This method does not rely on complex and expensive pretreatment equipment. The entire process analysis can be completed under conventional laboratory conditions. Moreover, only a small number of samples are needed to carry out multiple parallel tests, which minimizes the sample loss of rare and non-renewable wooden cultural relics. It conforms to the core principles of cultural relic protection and has good practicality and repeatability.

[0010] (3) The quantitative analysis method for hydrogen peroxide in wooden cultural relics provided in this application has excellent detection performance, reasonable linear response range, and detection limit that meets the needs of trace analysis. Practical verification shows that the spiked recovery effect is ideal and can accurately detect trace hydrogen peroxide in samples, meeting the stringent requirements of the field of cultural relic protection for the quantitative analysis of this indicator.

[0011] (4) The quantitative analysis method for hydrogen peroxide in wooden cultural relics provided in this application has a flexible and adaptable differential pretreatment design. The pretreatment parameters can be adjusted according to the differences in matrix composition of different wooden cultural relics (such as the abundance of metal ions and the types of organic components), which effectively expands the application scenarios of the method in the detection of different types of wooden cultural relic samples and improves the universality of the technical solution. At the same time, the signal difference between different pretreatment groups can also indirectly reflect the influence intensity and type of interfering substances in the matrix, providing a certain reference for subsequent analysis of the matrix characteristics of cultural relics and optimization of protection and restoration strategies. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 These are actual images of the wooden artifact samples used in the embodiments of this application; Figure 2 This is a linear calibration curve of hydrogen peroxide concentration-absorbance in the embodiments of this application. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0015] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such use of terms can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0016] Wooden artifacts are prone to oxidative aging during long-term preservation. Hydrogen peroxide, as a key intermediate product of photo-oxidation of lignocellulose and the Fenton reaction catalyzed by metal ions, is an important indicator for assessing the degree of deterioration and revealing the degradation mechanism of artifacts. However, the matrix composition of wooden artifacts is extremely complex, rich in metal ions such as iron / ferrous ions, as well as organic components such as lignin and extracts, posing a serious challenge to the accurate quantification of hydrogen peroxide. Specifically, metal ions can catalyze the Fenton reaction, causing the hydrogen peroxide content to change dynamically throughout the detection process, resulting in a systematically low measured value. At the same time, metal ions may compete with the colorimetric reagent for complexation, and organic components may produce background absorption, leading to falsely high measured values. These interfering factors in opposite directions are intertwined, and existing technologies are unable to effectively distinguish and subtract them, making it impossible to guarantee the accuracy of the detection results.

[0017] To address the aforementioned technical problems, this application proposes the following inventive concept: This application constructs parallel samples with different interference contributions through differentiated pretreatment, and uses the differential calculation principle to resolve the true content of endogenous hydrogen peroxide from complex matrix signals.

[0018] Specifically, the same wooden artifact sample is divided into multiple equal portions, and each portion undergoes different pretreatments to ensure calculable differences in the contributions of endogenous hydrogen peroxide and / or interfering substances. For example, some samples can be contacted with a hydrogen peroxide decomposing agent to selectively remove endogenous hydrogen peroxide, some with an interfering substance shielding agent to selectively shield against interference such as metal ions, some with an inert medium to maintain their original state, and some can be simultaneously contacted with both a hydrogen peroxide decomposing agent and an interfering substance shielding agent to simultaneously remove the target substance and shield against interference. After pretreatment, hydrogen peroxide is extracted from each sample, and its apparent content is measured. By mathematically differentiating the apparent contents, the true content of endogenous hydrogen peroxide can be accurately calculated, and the contribution of various interferences can also be quantified.

[0019] Based on the above concept, this application eliminates the need for complex separation and purification processes on the samples. Through simple pretreatment combinations and differential calculations, it effectively overcomes the multiple interferences caused by the complex matrix of wooden artifacts, achieving accurate quantification of endogenous hydrogen peroxide. Experiments demonstrate that this method is simple to operate, highly sensitive, and reproducible, with spiked recoveries ranging from 90.4% to 102.7%. It fully meets the requirements for accurate detection of trace hydrogen peroxide in wooden artifacts, providing reliable technical support for artifact deterioration assessment and conservation strategy formulation.

[0020] The technical solution of this application will be further described below.

[0021] This application proposes a method for the quantitative analysis of hydrogen peroxide in wooden artifacts, comprising the following steps: The wooden artifact sample to be tested was divided into multiple equal sub-samples; By performing differentiated pretreatment on samples of different equal divisions, the contribution of endogenous hydrogen peroxide and / or interfering substances in each sample to the final detection signal can be calculated differently. Hydrogen peroxide was extracted from each of the pretreated aliquots to obtain the corresponding extracts; The apparent content of hydrogen peroxide in each extract was determined; and based on the differences between the measured apparent contents, the true content of endogenous hydrogen peroxide in each extract was calculated.

[0022] The quantitative analysis method in this application can employ the following three pretreatment methods for processing samples of different aliquots.

[0023] In some implementations, the first preprocessing method includes: Take two equal portions of the wooden artifact sample to be tested, namely the first equal portion and the second equal portion; immerse the two equal portions in water to ensure that they are fully soaked; Add hydrogen peroxide decomposing agent to the soaking solution containing the first aliquot of sample, so that the first aliquot of sample comes into contact with the hydrogen peroxide decomposing agent to selectively remove endogenous hydrogen peroxide. The second aliquot of the soaked sample was left untreated. The actual content of the endogenous hydrogen peroxide is calculated using the following formula (1): ΔC 内源 =C 原始 -C 分解 (1); Among them, C 原始 The apparent content measured for the second aliquot of the sample without any treatment, C 分解The apparent content was measured in the first aliquot of the sample after treatment with the hydrogen peroxide decomposition agent. It is understood that the first pretreatment method employed a two-control design. Through the selective action of the hydrogen peroxide decomposition agent, endogenous hydrogen peroxide in the first aliquot was completely removed, while other interfering substances (such as lignin, extracts, and other organic components, as well as metal ions) were retained; the second aliquot remained in its original state, with no change to endogenous hydrogen peroxide or any interfering substances. Based on this design, C 分解 C represents the contribution of interfering substances and background signals. 原始 This represents the total contribution of endogenous hydrogen peroxide, interfering substances, and background signals. By calculating the difference between the two, interference and background can be subtracted to obtain the true content of endogenous hydrogen peroxide. This method requires only two control groups, eliminating the need for additional reagents such as chelating agents or complex separation and purification steps. The entire process of pretreatment, extraction, and determination can be standardized and completed in a standard analytical laboratory equipped with a UV-Vis spectrophotometer. This method is particularly suitable for scenarios with a large number of samples requiring rapid screening, demonstrating good practicality and widespread applicability. Furthermore, the low-temperature static immersion treatment avoids secondary damage to wooden artifact samples that may be caused by high temperatures, strong acids or alkalis, or violent chemical reactions. The treated samples can still be used for analysis and testing in other projects, conforming to the principles of "minimal intervention" and "maximum sample information" in cultural relic protection.

[0024] As a specific implementation of the first pretreatment method, the hydrogen peroxide decomposing agent is preferably a catalase solution with an enzyme activity of 1000 U / mL to 5000 U / mL. In operation, equal aliquots of the sample are first mixed with water at a mass ratio of 1:5 to 1:15 and soaked to provide a suitable environment for the enzymatic reaction. Then, the aforementioned catalase solution is added to the soaking solution, and the mixture is allowed to stand at a low temperature (0–4°C) for 24 to 72 hours. During this process, catalase can efficiently catalyze the decomposition of hydrogen peroxide into water and oxygen. By controlling the enzyme activity range, solid-liquid ratio, and standing time, thorough and gentle removal of hydrogen peroxide at different initial concentrations can be achieved under mild conditions, effectively avoiding the loss of analytes that may occur with traditional heating decomposition methods.

[0025] In some implementations, the second preprocessing method includes: Take two equal portions of the wooden artifact sample to be tested, namely the first equal portion and the second equal portion; immerse the two equal portions in water to ensure that they are fully soaked; Add an interference shielding agent to the soaking solution containing the first aliquot of the sample, so that the first aliquot of the sample comes into contact with the interference shielding agent, in order to selectively shield the influence of the interference substance on the determination of hydrogen peroxide. Add hydrogen peroxide decomposing agent and interference shielding agent to the soaking solution containing the second aliquot of the sample, so that the second aliquot of the sample can be in contact with both the hydrogen peroxide decomposing agent and the interference shielding agent at the same time; in order to selectively remove endogenous hydrogen peroxide and selectively shield the influence of interference substances on the determination of hydrogen peroxide. The actual content of the endogenous hydrogen peroxide is calculated using the following formula (2): ΔC 内源 =C 屏蔽 -C 联合 (2); Among them, C 屏蔽 The apparent content, C, is the first aliquot of the sample treated with the interfering substance shielding agent. 联合 The apparent content was measured in the second aliquot of the sample after combined treatment with a hydrogen peroxide decomposition agent and an interference shielding agent. It is understandable that the second pretreatment method employs a two-control design, the core of which lies in selectively eliminating the influence of interfering factors such as metal ions through the interference shielding agent.

[0026] The first aliquot of the sample is contacted with an interference-shielding agent. This agent (such as EDTA-2Na) specifically binds to metal ions in the sample, rendering them inactive and unable to compete for complexation, thus shielding them from interference by metal ions in the determination of hydrogen peroxide. After this treatment, the endogenous hydrogen peroxide in the sample is completely preserved, while the catalytic decomposition and competitive complexation interference caused by metal ions are effectively suppressed. Therefore, C 屏蔽 This represents the total contribution of endogenous hydrogen peroxide and residual background signals (such as organic component absorption, reagent blank, etc.).

[0027] The second aliquot of the sample is simultaneously exposed to both a hydrogen peroxide decomposing agent and an interference-shielding agent. The interference-shielding agent also shields against metal ion interference, while the hydrogen peroxide decomposing agent selectively removes endogenous hydrogen peroxide. After this combined treatment, the endogenous hydrogen peroxide in the sample is completely decomposed, metal ion interference is shielded, and only non-specific background signals remain. Therefore, C 联合 This represents the contribution of the background signal.

[0028] Based on the above design, through C 屏蔽 Subtract C 联合This allows for the subtraction of background signals, yielding the true content of endogenous hydrogen peroxide. This embodiment employs an interference-shielding agent (such as EDTA-2Na) to specifically complex metal ions, rendering them inactive and protecting hydrogen peroxide from the Fenton reaction, thus ensuring the integrity of the analyte. In the titanium salt colorimetric method, this embodiment eliminates competitive complexation interference by complexing metal ions with the interference-shielding agent, ensuring the normal progress of the colorimetric reaction. Compared to existing methods that attempt to purify the target analyte through solid-phase extraction, column chromatography, and other separation techniques, this embodiment eliminates the need for complex sample pretreatment. Interference is eliminated through simple pretreatment and differential calculation, significantly simplifying the operation and reducing the risk of sample loss. Furthermore, this embodiment requires only two control groups to effectively eliminate metal interference and accurately quantify endogenous hydrogen peroxide, ensuring both accuracy and detection efficiency, making it suitable for research scenarios requiring the simultaneous processing of multiple samples.

[0029] As a specific implementation of the second pretreatment method, differentiated pretreatment procedures are adopted for different aliquots of the sample. Specifically, the aliquots are mixed with water at a mass ratio of 1:5 to 1:15 and soaked. For the first aliquot, a hydrogen peroxide decomposing agent is added to the soaking solution, followed by standing at a low temperature (0–4°C) for 24 to 72 hours to remove hydrogen peroxide present in the sample. For the second aliquot, both a hydrogen peroxide decomposing agent and an interfering substance shielding agent are added to the soaking solution, and the sample is also left to stand at a low temperature (0–4°C) for 24 to 72 hours.

[0030] The hydrogen peroxide decomposing agent is preferably a catalase solution with an enzyme activity of 1000 U / mL to 5000 U / mL, used for efficient decomposition of hydrogen peroxide. The interference shielding agent is preferably a disodium ethylenediaminetetraacetate (EDTA-2Na) solution with a concentration of 0.05 mol / L to 0.2 mol / L, used to complex and mask metallic interfering substances such as iron ions in the sample. Through the above treatment, the first aliquot of the sample only removes hydrogen peroxide while retaining metallic components such as iron ions, while the second aliquot of the sample removes hydrogen peroxide while complexing and masking iron ions. After being subjected to the same low-temperature (0-4℃) standing treatment, both aliquots can be used for subsequent analysis and determination of different target components, such as calculating the iron content by comparing the results with control detection results, thereby effectively eliminating cross-interference between hydrogen peroxide and metal ions and improving analytical accuracy. This method is simple to operate and operates under mild conditions.

[0031] When there is significant metallic interference in the sample and it is necessary to comprehensively assess the contribution of various types of interference, the third preprocessing method, which includes four sets of controls in this application, can be used to obtain more comprehensive interference analysis information.

[0032] In some implementations, the third preprocessing method includes: Take four equal portions of the wooden artifact sample to be tested, namely the first equal portion, the second equal portion, the third equal portion, and the fourth equal portion; immerse each of the four equal portions in water to ensure that they are fully soaked. Add hydrogen peroxide decomposing agent to the soaking solution containing the first aliquot of sample, so that the first aliquot of sample comes into contact with the hydrogen peroxide decomposing agent to selectively remove endogenous hydrogen peroxide. Add an interference shielding agent to the soaking solution containing the second aliquot of the sample, so that the second aliquot of the sample comes into contact with the interference shielding agent, in order to selectively shield the influence of the interference substance on the determination of hydrogen peroxide. Add hydrogen peroxide decomposing agent and interference shielding agent to the soaking solution containing the third aliquot of the sample, so that the third aliquot of the sample can be in contact with both the hydrogen peroxide decomposing agent and the interference shielding agent at the same time, so as to selectively remove endogenous hydrogen peroxide and selectively shield the influence of interference substances on the determination of hydrogen peroxide. The fourth aliquot of the soaked sample was left untreated. By comparing the apparent content measured using the above treatment methods, the true content of endogenous hydrogen peroxide was calculated and the impact of interfering substances was assessed, whereby: The actual content of endogenous hydrogen peroxide is calculated using the following formula (3) or formula (4): ΔC 内源 =C 原始 -C 分解 (3); ΔC 内源 =C 屏蔽 -C 联合 (4); The apparent content caused by interfering substances is calculated using the following formula (5) or formula (6): ΔC 干扰 =C 原始 -C 屏蔽 (5); ΔC 干扰 =C 分解 -C 联合 (6); Among them, C 屏蔽 The apparent content, C, is the value measured in the second aliquot of the sample after treatment with an interfering substance shielding agent. 联合 The apparent content of C is measured in the third aliquot of the sample after combined treatment with a hydrogen peroxide decomposition agent and an interfering substance shielding agent. 分解 The apparent content of C is measured in the first aliquot of the sample after treatment with the hydrogen peroxide decomposition agent. 原始 The apparent content was measured in the fourth aliquot of the sample without any treatment.

[0033] The third preprocessing method employs a complete design with four sets of controls. By constructing parallel samples with four different interference states, it achieves systematic analysis and subtraction of various interferences in complex matrices. The third preprocessing method and its corresponding signal composition are as follows: Table 1. Preprocessing methods and their corresponding signal structures Based on the above four types of apparent content, the following information can be obtained through the following difference calculation: (1) Calculation of the true content of endogenous hydrogen peroxide: ΔC 内源 =C 原始 -C 分解 (3); ΔC 内源 =C 屏蔽 -C 联合 (4); Formula (3) represents: the total apparent content (C) of the untreated sample. 原始 ) and apparent content after removing only endogenous hydrogen peroxide (C 分解 The difference between the two values ​​is the true content of endogenous hydrogen peroxide. This calculation method uses a system in which endogenous hydrogen peroxide is specifically decomposed as a control, directly subtracting non-target signals to obtain the net content of endogenous hydrogen peroxide.

[0034] Formula (4) represents: under the condition that metal ion interference is shielded, the apparent content (C) of the sample after interference shielding treatment is: 屏蔽 The apparent content (C) after interference shielding and combined treatment with endogenous hydrogen peroxide was compared with that after treatment. 联合 The difference between the two values ​​represents the true content of endogenous hydrogen peroxide. This method simultaneously eliminates interference from metal ions and organic background absorption, and the results are unaffected by differences in the sample matrix, exhibiting high accuracy and comparability.

[0035] (2) Calculation of the interference caused by metal ions: ΔC 干扰 =C 原始 -C 屏蔽 (5); ΔC 干扰 =C 分解 -C 联合 (6); Formula (5) represents: the apparent content (C) of the fourth aliquot sample without any interference shielding treatment. 原始 The apparent content (C) of the second aliquot sample treated with metal interference shielding was compared with that of the first aliquot sample. 屏蔽The difference between C and C represents the amount of interference caused by metal ions in the measurement. 原始 Including endogenous, metal interference, and organic background, C 屏蔽 It only includes endogenous and organic background, and the difference between the two can directly quantify the degree of interference of metal ions on the determination of hydrogen peroxide.

[0036] Formula (6) represents: the apparent content (C) of the first aliquot of the sample after endogenous hydrogen peroxide decomposition treatment. 分解 ) and the apparent content (C) of the third aliquot of the combined-treatment sample 联合 The difference between C and C also characterizes the amount of measurement interference caused by metal ions. 分解 Including metallic interference and organic background, C 联合 With only organic background included, the difference between the two can independently determine the interference contribution of metal ions under the premise of eliminating the influence of endogenous hydrogen peroxide, and form cross-validation with formula (5) to improve the reliability of the results.

[0037] (3) For the background signal C of organic components 背景 The calculation is performed using the following formula (7): C 背景 =C 联合 (7) ; C 背景 This represents the non-specific background absorption produced by organic components such as lignin and extracts at characteristic absorption wavelengths. (C) 联合 This represents the background absorbance of organic components. If this value is too high (e.g., exceeding the method detection limit), it indicates a high content of organic extracts in the sample, which may require adjustment of the extraction method or correction of the results. This provides a basis for judging the applicability of the method in different types of samples.

[0038] (4) Fenton reaction loss ΔC 损失 The calculation is performed using the following formula (8): ΔC 损失 =C 屏蔽 -C 原始 (8); ΔC 损失 It reflects the amount of hydrogen peroxide that is decomposed by the Fenton reaction catalyzed by metal ions when there is no shielding protection.

[0039] As a specific implementation plan for the third pretreatment method, three differentiated pretreatment procedures are set up for different equal-amplitude samples to eliminate the influence of different interfering substances through comparative analysis. The specific operation is as follows: the equal-amplitude samples are mixed with water at a mass ratio of 1:5 to 1:15 and soaked to obtain three sets of parallel samples. For the first equal-amplitude sample, only hydrogen peroxide decomposing agent is added to the soaking solution, and then it is treated at low temperature (0-4℃) for 24 to 72 hours to remove hydrogen peroxide present in the sample, while retaining metal components such as iron ions; for the second equal-amplitude sample, only interfering substance shielding agent is added to the soaking solution, and it is also treated at low temperature (0-4℃) for 24 to 72 hours to complex and mask metal interfering substances such as iron ions, while retaining hydrogen peroxide components; for the third equal-amplitude sample, both hydrogen peroxide decomposing agent and interfering substance shielding agent are added to the soaking solution, and it is also treated at low temperature (0-4℃) for 24 to 72 hours to remove hydrogen peroxide and mask iron ions.

[0040] The hydrogen peroxide decomposing agent is preferably a catalase solution with an enzyme activity of 1000 U / mL to 5000 U / mL, used for efficient decomposition of hydrogen peroxide; the interference shielding agent is preferably a disodium ethylenediaminetetraacetate (EDTA-2Na) solution with a concentration of 0.05 mol / L to 0.2 mol / L, used for complexing and masking iron ions in the sample.

[0041] Through the above three parallel treatments, samples with only hydrogen peroxide removed, samples with only iron ions masked, and samples with both hydrogen peroxide and iron ions removed and masked can be obtained, respectively. After being subjected to the same low-temperature (0–4°C) settling treatment, all three samples can be used for subsequent analysis and determination of different target components. For example, by comparing the detection results of the three sets of samples, the hydrogen peroxide content, iron ion content, and the degree of mutual interference when the two coexist can be calculated separately, thereby effectively eliminating cross-interference in complex matrices and achieving separate quantitative analysis of multiple components. This scheme is rigorously designed and operates under mild conditions, making it particularly suitable for complex sample pretreatment needs that require simultaneous determination of multiple interfering components or assessment of interference effects. Different pretreatment procedures are adopted for different aliquots of the sample. When establishing new methods for detecting hydrogen peroxide in wooden artifacts, a third pretreatment method can be used as a standard to verify the accuracy of simplified methods. For example, the reliability of a two-group method can be verified using a four-group method. The third pretreatment method can be used to study the distribution patterns of metal ion content, Fenton reactivity, and organic background levels in wooden artifacts from different sources, providing fundamental data for the formulation of artifact conservation strategies. For complex samples with unclear matrices and interference, the third pretreatment method can obtain the most accurate endogenous content while providing a comprehensive understanding of sample characteristics. When transferring the method to other laboratories or conducting long-term monitoring, the third pretreatment method can be periodically used for verification to ensure the continued reliability of the test results.

[0042] In some embodiments, a pre-inspection step is included before the differential pretreatment of the aliquots. This step aims to accurately determine the iron content level in the sample substrate, providing a basis for the subsequent addition of the interfering substance shielding agent. Specifically, the total iron content of the aliquots is detected using conventional analytical methods such as colorimetry or titration. Based on this pre-inspection result, when adding the interfering substance shielding agent to the sample to mask iron ions, an excess of 1.1 to 2 times the theoretical amount required to remove iron is added. This design ensures that iron ions of different forms or contents that may exist in the sample are sufficiently complexed and masked, avoiding interference with the subsequent detection of target components, while also preventing excessive addition of the interfering substance shielding agent, which could lead to reagent waste or the introduction of new impurities.

[0043] To further optimize the shielding effect and adapt to complex reaction systems, the preferred method for adding the aforementioned interfering substance shielding agent is an intermittent addition strategy. Specifically, the calculated total amount of shielding agent is added to the sample in batches, with the time interval between each addition controlled to be between 4 and 12 hours. This batch-intermittent addition method helps maintain a continuous and effective concentration of the interfering substance shielding agent in the reaction system, overcoming the problem that excessive addition at one time may lead to violent local reactions or hydrolysis failure of the shielding agent, ensuring that the shielding reaction can proceed smoothly and fully, which is especially suitable for analytical scenarios with long reaction cycles or complex sample matrices.

[0044] In some embodiments, when adding hydrogen peroxide decomposing agent to the soaking solution containing equal aliquots of the sample, the hydrogen peroxide decomposing agent is also added intermittently, with an interval of 4 to 12 hours between each addition. Before each addition of new hydrogen peroxide decomposing agent, the reaction system is tested using a dedicated test strip (e.g., a semi-quantitative hydrogen peroxide test strip) to determine whether the previously added hydrogen peroxide has reacted completely. If the test strip shows no hydrogen peroxide residue, no further addition is needed; if residue is still present, the next addition is performed as planned. This closed-loop control method of "intermittent addition + real-time detection" ensures that hydrogen peroxide is completely decomposed, eliminating its oxidative interference with subsequent measurements, while also avoiding unnecessary consumption of the decomposing agent and achieving accurate determination of the reaction endpoint.

[0045] In some embodiments, the apparent content of hydrogen peroxide in each extract is determined by spectrophotometry, fluorescence spectroscopy, chemiluminescence, or electrochemical analysis. When spectrophotometry is used to determine the apparent content of hydrogen peroxide in each extract, the following steps are included: Establishing a standard curve: Prepare a series of hydrogen peroxide standard solutions of different concentrations. Add titanium salt colorimetric reagent to each standard solution to allow hydrogen peroxide to react with titanium salt to form hydrogen peroxide-titanium complex. After centrifugation to separate the precipitate, discard the supernatant, add precipitate dissolving agent, and measure the absorbance at a wavelength of 415 nm with a blank solution as a reference. Perform linear regression with hydrogen peroxide concentration as the abscissa and absorbance as the ordinate to obtain the standard curve equation. Sample determination: Add titanium salt colorimetric reagent to the extract to be tested, so that hydrogen peroxide reacts with titanium salt to form hydrogen peroxide-titanium complex. After centrifugation to separate the precipitate, discard the supernatant, add precipitate dissolving agent, and measure absorbance at 415 nm wavelength with blank solution as reference. Content Calculation: The measured absorbance of the sample is substituted into the standard curve equation to calculate the apparent content of hydrogen peroxide in the extract. A stable complex is specifically formed between titanium salt colorimetric reagent and hydrogen peroxide, and detection is performed using the characteristic absorption wavelength of 415 nm, providing good specificity and effectively reducing interference from non-specific absorption of organic components in the wooden artifact matrix. The detection process includes centrifugation to separate the precipitate and discard the supernatant, which can specifically remove some soluble organic impurities, further reducing matrix background interference and improving the signal-to-noise ratio. The addition of a precipitant dissolving agent promotes the complete dissolution of the complex, ensuring the stability and reproducibility of the absorbance measurement. Combined with a linear regression equation established using a series of concentration standard solutions, a rigorous calibration basis is provided for the quantification of apparent content. The entire photometric detection procedure is well-organized, requiring no complex or expensive equipment, and the operation is easy to standardize and control. In addition to the photometric method described in this application, the apparent content of hydrogen peroxide in the extract can also be determined using conventional detection methods such as fluorescence spectroscopy, chemiluminescence, and electrochemical analysis.

[0046] In some embodiments, the wooden artifact samples include a pretreatment step before being divided into equal portions. For ancient, decayed, and soft wooden samples, they are gently rinsed with deionized water and then directly ground to divide them into equal portions for subsequent testing. The rinsing process removes external contaminants such as dirt, dust, and salt adhering to the sample surface, avoiding interference from impurities on subsequent test results. The entire process employs a gentle operating mode, eliminating the need for high-intensity mechanical processing. This maximizes the preservation of the original components and structural characteristics of the sample, preventing excessive damage and loss of decayed wood, while simplifying the sample preparation process. This aligns with the non-destructive and minimal-destructive testing requirements of fragile, ancient wooden artifacts, balancing sample integrity and testing feasibility. For more recent, hard, and dense wooden samples, they must first be rinsed with deionized water, followed by crushing, homogenization, and sieving. The pulverization and homogenization processes ensure uniform particle size and composition, guaranteeing consistent background content and matrix characteristics across all aliquots, thus laying a solid foundation for subsequent differential pretreatment and comparative analysis. Sieving removes large particles and impurities, further enhancing sample homogeneity and representativeness, and preventing measurement errors caused by sample inhomogeneity. The pretreated samples exhibit a significantly increased specific surface area, facilitating thorough penetration of the pretreatment solution and full contact with reactants, effectively improving pretreatment efficiency and target analyte extraction completeness. The entire pretreatment process is simple to operate, utilizes widely available equipment, and is adaptable to various types of wooden artifact samples, fully demonstrating the practicality and universality of the proposed method.

[0047] In some implementations, a spiked recovery test step is also included: a known amount of hydrogen peroxide standard is added to a wooden artifact sample with a known hydrogen peroxide content, and then the determination is performed according to the aforementioned method to calculate the recovery rate, thereby assessing the accuracy of the quantitative analysis method. It is understood that, firstly, the recovery rate results can verify whether the differential pretreatment and differential calculation effectively eliminate matrix interference; if the recovery rate is close to 100% (e.g., 90%-105%), it proves that the method has high accuracy and thorough interference subtraction. Secondly, the spiked recovery test can serve as an internal quality control measure for batch-to-batch result comparison and method stability monitoring. Finally, by determining the recovery rate at different spike concentration levels, the applicability of the method within different content ranges can also be evaluated, providing a basis for the application of this method in different types of samples.

[0048] To verify the feasibility and accuracy of the above-mentioned technical solution, a series of experimental studies were conducted using wooden artifact samples unearthed from the Mengxihe site. The method of this application is described in detail below with reference to specific embodiments, and its technical effectiveness is demonstrated through experimental data.

[0049] I. Experimental Materials, Reagents and Instruments 1. Pretreatment of experimental materials: Wooden artifact samples used in the experiment (such as...) Figure 1 The wooden artifact sample (shown) was unearthed from the Mengxihe site. The sample underwent pretreatment, and the specific treatment process is as follows: (1) Initial treatment of samples: wooden artifacts unearthed from the Mengxihe site were taken and the surface deposits were repeatedly rinsed with deionized water. After rinsing, the samples were dried in a vacuum drying oven at 15℃ and 100Pa for 12 hours. At this time, the moisture content of the wooden artifacts was less than 1%.

[0050] (2) Due to the age of the wooden artifact sample, the wooden sample has become soft and decayed, and can be easily crushed into powder by hand. No pulverizer is needed. It can be directly ground with an agate mortar. Take the wooden artifact sample after the initial treatment in step (1), place it in an agate mortar, and add deionized water. The mass ratio of the wooden artifact sample to the deionized water is 1:1. Grind it thoroughly by hand until a uniform sample slurry is formed.

[0051] (3) Equal division and pre-inspection: Take the sample slurry obtained from grinding in step (2), weigh five equal portions of 100.00g (±0.0002g), one portion is used as a pre-inspection sample, and the total iron content is determined by the o-phenanthroline colorimetric method (detection wavelength 510nm). The determination is performed in parallel 3 times, and the average value is taken as the basic iron content data of this batch of samples.

[0052] 2. Reagents and Instruments: The hydrogen peroxide content detection kit (catalog number: BC3595) was purchased from Beijing Solarbio Science & Technology Co., Ltd. The kit contains reagent 1 (acetone to be prepared by the user), reagent 2 (powder, to be prepared by the user), reagent 3, reagent 4, and hydrogen peroxide standard solution (1 mmol / mL).

[0053] Catalase (catalog number: C116863) was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with an enzyme activity greater than 200,000 units / g.

[0054] Disodium ethylenediaminetetraacetate (EDTA-2Na, analytical grade) was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0055] Hydrochloric acid (analytical grade) and acetone (analytical grade) were both purchased from Chengdu Jinshan Chemical Reagent Co., Ltd.

[0056] All water used in the experiments was ultrapure water.

[0057] HACH DR6000 UV-Vis spectrophotometer (HACH Corporation, USA).

[0058] DZF-6090A Vacuum Drying Oven (Background: Zhongxing Weiye Century Instruments Co., Ltd.) Shanghai Hengping Electronic Balance FB124 (accuracy 0.1 mg).

[0059] II. Solution Preparation Preparation of Reagent 2: Prepare according to the instructions of the hydrogen peroxide content detection kit. Add concentrated hydrochloric acid to Reagent 2 just before use and dissolve thoroughly until the solution is pale yellow. This solution provides titanium ions in the subsequent colorimetric reaction, forming a yellow titanium peroxide complex with hydrogen peroxide. The determination principle is that hydrogen peroxide reacts with titanium salts in an acidic medium to form a stable yellow titanium peroxide complex. This complex exhibits characteristic absorption at a wavelength of 415 nm, and its absorbance shows a linear relationship with the hydrogen peroxide concentration within a certain range.

[0060] EDTA-2Na solution (0.1 mol / L): Accurately weigh 3.722 g of EDTA-2Na, dissolve it in ultrapure water and dilute to 100 mL.

[0061] Catalase solution: Dissolve catalase in 10 mL of phosphate buffer at pH 7.4 to prepare a pretreatment solution with an enzyme activity concentration of approximately 3000 U / mL. Store at 4°C and use within one week.

[0062] Hydrogen peroxide standard working solution: Using the hydrogen peroxide standard solution (1 mmol / mL) provided in the kit, dilute stepwise with acetone to accurately prepare a series of standard solutions with concentrations of 1 μmol / L, 5 μmol / L, 10 μmol / L, 30 μmol / L, 50 μmol / L, 75 μmol / L, and 100 μmol / L.

[0063] III. Determination of Hydrogen Peroxide Content in Wooden Cultural Relics This embodiment uses a four-group control method to quantitatively analyze hydrogen peroxide in wooden artifact samples unearthed from the Mengxihe site. The specific steps are as follows: Step S10: Establishing the standard curve Take 50 μL of each of the above-prepared series of standard solutions and place them in separate centrifuge tubes. Add 100 μL of reagent II working solution and 2000 μL of reagent III to each tube in sequence, mix well, and centrifuge at 12000 r / min for 10 min at room temperature. Discard the supernatant and retain the precipitate. Add 1000 μL of reagent IV to the precipitate to dissolve it, and let it stand at room temperature (25±2℃) in the dark for 5 min.

[0064] A solution treated with the same steps and 50 μL of acetone instead of the standard solution was used as a reference solution. The absorbance of the above standard solutions and reference solutions was measured at a wavelength of 415 nm using a HACH DR6000 UV-Vis spectrophotometer (HACH Corporation, USA). Based on the measurement results, a univariate linear regression was performed with hydrogen peroxide concentration (C, μmol / L) as the x-axis and absorbance (A) as the y-axis, yielding the standard curve equation: A = 0.0215C + 0.0574. This equation showed good fit in the concentration range of 1-100 μmol / L, with a coefficient of determination R0. 2 =0.9969, indicating a highly linear correlation between absorbance and hydrogen peroxide concentration. For example... Figure 2 The figure shows the linear calibration curve of hydrogen peroxide concentration versus absorbance.

[0065] Based on the aforementioned standard curve and detection system, the limit of detection (LOD) was determined by performing at least 10 parallel measurements on the reagent blank solution (a solution treated with 50 μL acetone instead of the standard solution and following the same steps), calculating the standard deviation of absorbance (σ), and then using the formula LOD = 3.3σ / k (where k is the slope of the standard curve). The detection limit of this method is 0.42 μM, which can achieve accurate detection of trace amounts of hydrogen peroxide and meet the analytical needs of low-content target substances in wooden cultural relics.

[0066] To verify the precision of the method, standard solutions at three concentration levels of 10 μmol / L, 50 μmol / L, and 100 μmol / L were selected, and each concentration was measured in triplicate. The relative standard deviation (RSD) of the measurement results was calculated to be 0.2%-0.5%, indicating that the method has good repeatability and the results of multiple parallel measurements are stable and reliable.

[0067] The accuracy of the method was further verified through spiked recovery experiments. Hydrogen peroxide standard solution equivalent to 0.5 times, 1 times, and 2 times the background content was added to samples with known background content, respectively. After determination according to this method, the recovery rate was calculated as (measured amount after spike - background amount) / added amount × 100%. The recovery rate was 90.4%-102.7% after three parallel determinations, indicating that the measured results deviated little from the true value, effectively overcoming matrix interference and ensuring the accuracy of quantitative results.

[0068] Step S20: Sample grouping and pretreatment Step S201: Take an equal sample and perform a preliminary test. The total iron content is measured to be 0.26 μmol / g. Add EDTA-2Na at twice the theoretical amount required to remove iron.

[0069] Step S202: Take four equal portions of the sample, place each portion in one of four beakers, add 1L of ultrapure water to each beaker, soak and mix thoroughly, and then pretreat the four portions of the sample according to the following pretreatment method: First aliquot: Add catalase solution to the soaking solution of the first aliquot. Add 1.00 mL of catalase solution with an enzyme activity of 3000 U / mL every 12 hours. Mix thoroughly after each addition and place in a 4°C refrigerator in the dark for soaking. Take a sample after 46 hours. If no hydrogen peroxide is found in the soaking solution, stop adding catalase solution. Continue soaking at 4°C in the dark for a total of 48 hours to ensure complete reaction.

[0070] Second aliquot: Add 0.1 mol / L disodium ethylenediaminetetraacetate (EDTA-2Na) solution to the soaking solution of the second aliquot every 12 hours, with each addition being 1.00 mL; after each addition, mix thoroughly and place in a 4℃ refrigerator in the dark for continuous soaking treatment for 48 hours to ensure that the interference of metal ions is fully shielded.

[0071] For the third aliquot: Add 1.00 mL of 0.1 mol / L disodium ethylenediaminetetraacetate (EDTA-2Na) solution and 1.00 mL of catalase solution with an enzyme activity of 3000 U / mL to the soaking solution of the third aliquot every 12 hours. Mix thoroughly after each addition and place in a 4°C refrigerator in the dark for soaking. Samples were taken after 46 hours; when no hydrogen peroxide was found in the soaking solution, the addition of catalase solution was stopped. Thereafter, disodium ethylenediaminetetraacetate (EDTA-2Na) solution was added at intervals, and the soaking was continued at 4°C in the dark for a total of 48 hours to ensure complete reaction.

[0072] Fourth aliquot of sample: No treatment was performed. The sample was placed in a 4°C refrigerator and kept in the dark for 48 hours for continuous immersion.

[0073] Step S30: Hydrogen peroxide extraction and color development Step S301: After pretreatment, discard the liquid in each beaker. Immediately place each pretreated aliquot into a mortar containing ice packs, add 1.00 mL of reagent one (acetone) pre-cooled to 4°C, and then grind and crush for 5 minutes to ensure thorough homogenization and extraction. Centrifuge the homogenate at 8000 rpm for 10 minutes at 4°C to precipitate insoluble matter. Carefully aspirate the supernatant from each aliquot and transfer it to separate centrifuge tubes. Then, perform the colorimetric reaction in step S302 below on the supernatant of each sample.

[0074] Step S302: The colorimetric reaction is performed according to the method for establishing the standard curve in step S10: The supernatant of each sample is subjected to the following operations in sequence: Add 50 μL of reagent II application solution and 100 μL of reagent III to each centrifuge tube containing the supernatant of equal sample, mix well, centrifuge at 8000 rpm for 10 min, discard the supernatant, and retain the precipitate; add 1000 μL of reagent IV to the precipitate to dissolve it, and then let it stand at room temperature (25±2℃) in the dark for 5 min to obtain the colorimetric solution to be tested corresponding to the four equal sample.

[0075] Step S303: Set up a blank control tube (using 50 μL of acetone instead of the sample supernatant) and a standard reference tube (using 50 μL of 25 μmol / L hydrogen peroxide standard working solution instead of the sample supernatant) to verify the effectiveness of the detection system; perform the colorimetric reaction of step S302 on the blank control tube and the standard reference tube; perform the following operations in sequence: add 50 μL of reagent II working solution and 100 μL of reagent III to the blank control tube and the standard reference tube respectively, mix well, centrifuge at 8000 rpm for 10 min, discard the supernatant, and retain the precipitate; add 1000 μL of reagent IV to the precipitate to dissolve it, and then let it stand at room temperature (25±2℃) in the dark for 5 min to obtain the colorimetric solution of the blank control tube and the standard reference tube.

[0076] S40: Absorbance Measurement and Content Calculation Using the blank control tube as a reference, the absorbance of the test solution and the standard reference tube's solution for all aliquots was measured at a wavelength of 415 nm. The measured absorbance values ​​are shown in Table 2 below: Table 2 Absorbance values The absorbance of the standard reference tube colorimetric solution, calculated from the standard curve, is in high agreement with the expected concentration of 25 μmol / L, indicating that the detection system is accurate and reliable.

[0077] Subtract the blank background (A) from the absorbance values ​​of the test colorimetric solution measured for each aliquot of the sample. 校正 =A 实测 After substituting -0.003 into the standard curve equation, A = 0.0215C + 0.0574, that is, A 校正 =0.0215C+0.0574, calculate the apparent concentration of hydrogen peroxide in each aliquot: First equal-divided sample: C 分解 =(0.298-0.0574) / 0.0215≈11.17μmol / L; Second equal-divided sample: C 屏蔽 =(0.651-0.0574) / 0.0215≈27.59μmol / L; Third equal-divided sample: C 联合 =(0.012-0.0574) / 0.0215≈-2.11μmol / L (a negative value is considered as 0, indicating that the background signal is below the method's lower limit of quantitation); Fourth aliquot: C 原始 =(0.891-0.0574) / 0.0215≈38.75μmol / L; S50: Interference Analysis and Determination of True Content Based on the above apparent concentration, the following results were obtained through differential calculation: (1) The true content of endogenous hydrogen peroxide in the test colorimetric solution of the aliquoted sample can be calculated using formulas (3) and (4): ΔC 内源 =C 原始 -C 分解 =38.75-11.17=27.58μmol / L; ΔC 内源 =C 屏蔽 -C 联合 =27.59-0=27.59μmol / L.

[0078] The two sets of independently calculated endogenous hydrogen peroxide concentrations showed a high degree of consistency with minimal relative deviation, indicating that this method possesses good repeatability and reliability. The ΔC obtained after correction using this method... 内源 It effectively eliminates the interference of metal ions and the influence of organic background absorption, truly reflects the endogenous hydrogen peroxide level contained in the sample itself, and the measurement results are accurate and stable, unaffected by matrix interference, and can be used for precise quantitative analysis of hydrogen peroxide in wooden cultural relics samples.

[0079] (2) The amount of interference caused by metal ions can be calculated using formulas (5) and (6): ΔC 干扰 =C 原始 -C 屏蔽 =38.75-27.59=11.16μmol / L; ΔC 干扰 =C 分解- C 联合 =11.17-0=11.17μmol / L; The metal ion interference values ​​obtained from the two independent calculation methods are basically consistent, and the results corroborate each other, indicating that the quantitative analysis of interference by this method is accurate and reliable. This value mainly reflects the positive interference caused by metal ions in the detection system, which is an important reason for the high results of traditional detection methods. Through the preprocessing and calculation methods of this application, this part of the interference can be effectively separated and subtracted, significantly improving the accuracy of endogenous hydrogen peroxide determination.

[0080] (3) After combined treatment with EDTA-2Na and catalase, C 联合 A value close to zero indicates that both specific and non-specific interferences have been effectively eliminated.

[0081] This application completes the pretreatment, grinding, and extraction operations entirely under low-temperature (0–4°C) conditions, which can effectively inhibit the Fenton-like reaction between metal ions and hydrogen peroxide, avoid the additional consumption or generation of endogenous hydrogen peroxide in the sample before detection, and retain its original content level to the maximum extent. At the same time, the low-temperature environment can reduce the activity of endogenous enzymes and the oxidation rate of organic matter in the sample, reduce matrix interference and background signal fluctuations, and further ensure the authenticity and stability of the measurement results.

[0082] The above results demonstrate that the method provided in this application can effectively distinguish and eliminate various interferences in the complex matrix of wooden cultural relics, and achieve accurate quantification of endogenous hydrogen peroxide.

[0083] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for quantitative analysis of hydrogen peroxide in wooden artifacts, characterized in that, Includes the following steps: The wooden artifact sample to be tested was divided into multiple equal sub-samples; By performing differentiated pretreatment on samples of different equal divisions, the contributions of endogenous hydrogen peroxide and interfering substances in each sample to the final detection signal can be calculated to be different. Hydrogen peroxide was extracted from each of the pretreated aliquots to obtain the corresponding extracts; The apparent content of hydrogen peroxide in each extract was determined. And based on the differences between the measured apparent contents, the true content of endogenous hydrogen peroxide in each extract was calculated; The preprocessing includes: Take four equal portions of the wooden artifact sample to be tested, namely the first equal portion, the second equal portion, the third equal portion, and the fourth equal portion; immerse each of the four equal portions in water to ensure that they are fully soaked. Add hydrogen peroxide decomposing agent to the soaking solution containing the first aliquot of sample, so that the first aliquot of sample comes into contact with the hydrogen peroxide decomposing agent to selectively remove endogenous hydrogen peroxide. Add an interference shielding agent to the soaking solution containing the second aliquot of the sample, so that the second aliquot of the sample comes into contact with the interference shielding agent, in order to selectively shield the influence of the interference substance on the determination of hydrogen peroxide. Add hydrogen peroxide decomposing agent and interference shielding agent to the soaking solution containing the third aliquot of the sample, so that the third aliquot of the sample can be in contact with both the hydrogen peroxide decomposing agent and the interference shielding agent at the same time, so as to selectively remove endogenous hydrogen peroxide and selectively shield the influence of interference substances on the determination of hydrogen peroxide. The fourth aliquot of the soaked sample was left untreated. By comparing the apparent content measured using the above treatment methods, the true content of endogenous hydrogen peroxide was calculated and the impact of interfering substances was assessed, whereby: The true content of endogenous hydrogen peroxide is measured by ΔC. 内源 =C 原始 -C 分解 Or ΔC 内源 =C 屏蔽 -C 联合 Perform calculations; Apparent content caused by interfering substances is measured by ΔC 干扰 =C 原始 -C 屏蔽 Or ΔC 干扰 =C 分解 -C 联合 Perform calculations; Among them, C 屏蔽 The apparent content, C, is the value measured in the second aliquot of the sample after treatment with an interfering substance shielding agent. 联合 The apparent content of C is measured in the third aliquot of the sample after combined treatment with a hydrogen peroxide decomposition agent and an interfering substance shielding agent. 分解 The apparent content of C is measured in the first aliquot of the sample after treatment with the hydrogen peroxide decomposition agent. 原始 The apparent content was measured in the fourth aliquot of the sample without any treatment.

2. The method for quantitative analysis of hydrogen peroxide in wooden artifacts according to claim 1, characterized in that, The mass ratio of the equal samples to water was 1:5 to 1:

15.

3. The method for quantitative analysis of hydrogen peroxide in wooden artifacts according to claim 1, characterized in that, After adding hydrogen peroxide decomposing agent to the soaking solution containing the first aliquot of the sample, the solution was left to stand at low temperature for 24 to 72 hours.

4. The method for quantitative analysis of hydrogen peroxide in wooden artifacts according to claim 1, characterized in that, After adding the interfering substance shielding agent to the soaking solution containing the second aliquot of the sample, the solution was left to stand at low temperature for 24 to 72 hours.

5. The method for quantitative analysis of hydrogen peroxide in wooden artifacts according to claim 1, characterized in that, After adding hydrogen peroxide decomposing agent and interference shielding agent to the soaking solution containing the third aliquot of the sample, the solution was left to stand at low temperature for 24 to 72 hours.

6. The method for quantitative analysis of hydrogen peroxide in wooden artifacts according to claim 1, characterized in that, The hydrogen peroxide decomposing agent is a catalase solution with an enzyme activity of 1000 U / mL to 5000 U / mL.

7. The method for quantitative analysis of hydrogen peroxide in wooden artifacts according to claim 1, characterized in that, The interference shielding agent is a solution of disodium ethylenediaminetetraacetate with a concentration of 0.05 mol / L to 0.2 mol / L.

8. The method for quantitative analysis of hydrogen peroxide in wooden artifacts according to claim 1, characterized in that, Before performing differential pretreatment on the equal-divided samples, the method further includes pre-inspection of the equal-divided samples to detect the total iron content of the equal-divided samples; when performing differential pretreatment on different equal-divided samples, the interference material shielding agent is added at 1.1-2 times the theoretical amount required to remove iron, based on the total iron content obtained from the pre-inspection. The total amount of the interference material shielding agent is added in batches at intervals of 4 to 12 hours.

9. The method for quantitative analysis of hydrogen peroxide in wooden artifacts according to claim 1, characterized in that, The hydrogen peroxide decomposing agent is added in batches at intervals of 4 to 12 hours. Before each addition of the hydrogen peroxide decomposing agent, the hydrogen peroxide in the aliquot sample is tested to determine whether the addition needs to continue.

10. The method for quantitative analysis of hydrogen peroxide in wooden artifacts according to claim 1, characterized in that, The apparent content of hydrogen peroxide in each extract was determined using spectrophotometry, fluorescence spectroscopy, chemiluminescence, or electrochemical analysis. When spectrophotometry was used to determine the apparent content of hydrogen peroxide in each extract, the following steps were included: Establishing a standard curve: Prepare a series of hydrogen peroxide standard solutions of different concentrations. Add titanium salt colorimetric reagent to each standard solution to allow hydrogen peroxide to react with titanium salt to form hydrogen peroxide-titanium complex. After centrifugation to separate the precipitate, discard the supernatant, add precipitate dissolving agent, and measure the absorbance at a wavelength of 415 nm with a blank solution as a reference. Perform linear regression with hydrogen peroxide concentration as the abscissa and absorbance as the ordinate to obtain the standard curve equation. Sample determination: Add titanium salt colorimetric reagent to the extract to be tested, so that hydrogen peroxide reacts with titanium salt to form hydrogen peroxide-titanium complex. After centrifugation to separate the precipitate, discard the supernatant, add precipitate dissolving agent, and measure absorbance at 415 nm wavelength with blank solution as reference. Content calculation: Substitute the measured absorbance of the sample into the standard curve equation to calculate the apparent content of hydrogen peroxide in the extract.

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