CN108802003B - Method for rapidly and nondestructively identifying silk product and content - Google Patents

Abstract

The invention discloses a method for rapid and non-destructive identification of silk products and their content. The steps of the invention are as follows: single-point scanning or imaging scanning is performed on the object to be identified using a visible laser Raman spectrometer to obtain a single or a series of Raman spectra; and then compared with the standard spectrum of silk to identify whether the object to be identified is a silk product, And the content of silk in the substance to be identified can be obtained by analysis, which is a method of applying modern scientific and technological means to the identification of silk products such as silk fabrics, silk cultural relics, silk materials, and silk works of art. The method for identifying silk products adopted in the present invention can not only realize traceless, non-destructive, simple and rapid identification of silk products, but also can quantitatively analyze silk products. Therefore, the present invention provides better identification and analysis of silk products. There are many choices and broad application prospects.

Description

A method for rapid and non-destructive identification of silk products and their content

technical field

The invention belongs to the field of biotechnology, and in particular relates to a method for rapid and non-destructive identification of silk products and their content.

Background technique

In addition to being used as a raw material for silk clothing in the textile industry, silk also has important uses in the fields of food, chemical industry, and biomedicine. Since silk protein is more expensive than other natural or synthetic fibers, there are often illegal traders in the market who mix other natural fibers (such as cotton, etc.) or synthetic fibers (such as polyester, nylon, etc.) or sell them completely as silk fibers, which seriously disrupts market order and infringe upon the rights and interests of consumers. In addition, archaeological sites often have textile residues unearthed, which need to be characterized and quantified. How to quickly, non-destructively and simply identify and quantify textile residues has received more and more attention and research in archaeological research. Therefore, developing a method for specific identification of silk products has great application prospects.

Common identification methods of silk products include combustion method, high performance liquid chromatography, infrared spectroscopy and so on. Combustion method is a widely known method for identifying silk fibers, but this method is not specific and requires high personnel, so there is a great misjudgment and the disadvantage of losing silk fibers. High-performance liquid chromatography is to dissolve silk fibers into an aqueous solution in high concentration of salt ions, and then identify the molecular weight of the silk solution by high-performance liquid chromatography. This method also has the disadvantage of low specificity and the need to destroy silk products. . Infrared spectroscopy, like high performance liquid chromatography, suffers from the disadvantages of poor specificity, the need to damage the sample and the complexity of the operation. To sum up, there is no simple, rapid and non-destructive method to identify and quantify silk products or silk materials.

SUMMARY OF THE INVENTION

In order to solve the problems existing in the background technology, the present invention provides a method for rapid and non-destructive identification of silk products and their content. The silk material is used as the target object without any treatment, and a commercial visualization laser Raman spectrometer is used to analyze the target object. Single-point scanning or imaging scanning is performed to obtain a single or a series of Raman patterns; and then compared with the standard pattern to identify whether the object to be identified is a silk product.

The technical scheme adopted in the present invention is as follows:

The method for rapid and non-destructive identification of silk products and content of the present invention comprises the following steps:

1) Use a visual laser Raman spectrometer to perform single-point scanning or imaging scanning on the object to be identified to obtain a single or a series of Raman spectra;

2) Compare the Raman spectrum obtained in step 2) with the standard spectrum of silk to identify whether the substance to be identified is a silk product.

The peak range of the standard spectrum of silk in the step 2) contains 3058-3062cm ^-1 , 2932-2936cm ^-1 , 2875-2880cm ^-1 , 1662-1668cm-1, 1446-1452cm ^-1 , 1228-1231cm ^-1 , 1081cm ^-1 -1086cm ^-1 , 851-855cm ^-1 , and the peak ranges of the strong characteristic peaks are 3058-3062cm ^-1 , 1662-1668cm ^-1 , 1446-1452cm ^-1 , 1228-1231cm ^-1 , 1081-1086cm ^-1 ; In the Raman spectrum obtained in the above step 1), there are at least four peaks located in the different species peak ranges of the silk standard spectrum, or at least three peaks located in the different species strong characteristic peak ranges of the silk standard spectrum, and The peak shape characteristics of the substance to be identified are similar to the standard spectrum of silk, that is, it is determined that the substance to be identified is a silk product or a raw material containing silk.

The scanning parameters during the scanning include laser power, exposure time, scanning times, pixels and total scanning time.

The scanning parameters during the scanning are set as: laser power 1-8 mW, exposure time 1-100 Hz, scanning times 1-300 times, and pixels 0.2-2 μm.

The Raman spectrum of the substance to be identified in the step 2) is compared with the standard spectrum of silk in the step 1), and the content of silk in the substance to be identified is determined by subtraction.

The standard spectrum of silk in the step 2) is obtained by reeling the spit cocoons to obtain silk fibers, and placing the silk fibers in a Raman spectrometer for testing.

The objects to be identified in the step 2) include silk fabrics, silk cultural relics, silk materials, and silk works of art.

The visual laser Raman spectrometer is an effective spectral analysis method for analyzing the composition and structure of substances. for Raman spectroscopy. Due to the unique molecular composition of silk protein, rapid, in-situ, reproducible and non-destructive detection of silk products can be performed by a visual laser Raman spectrometer (such as a laser confocal Raman spectrometer), and the components of silk molecules can be detected, Effective information such as structure and relative content, so as to achieve the purpose of simple, rapid and non-destructive identification of silk products.

Beneficial effects of the present invention:

1) Fast: the present invention does not require any pretreatment to the sample, the spectrum can be obtained in about 0.5 minutes, and complex data analysis of the obtained results is not required;

2) Non-destructive: The present invention does not require any treatment of the sample, does not damage the original sample, and can directly put the sample into the Raman spectrometer for single-point detection;

3) Strong specificity: the Raman spectrum of the silk fiber obtained by the present invention is obviously different from the Raman spectrum of other natural or synthetic fibers;

4) High sensitivity: the sample selected by the present invention can be a macroscopic silk product or a micron-sized silk product, all of which can be identified;

5) Qualitative analysis: the present invention can carry out precise and deterministic analysis on the analyte mixed with fibroin, and can also perform in-situ analysis on the analyte to accurately measure the content and distribution of fibroin in the analyte.

Description of drawings

Accompanying drawing 1 is embodiment 1 silk standard collection of illustrative plates;

Accompanying drawing 2 is that in embodiment 2, silk product is compared with other fiber atlas;

Accompanying drawing 3 is the spectrum of silk products of different forms in embodiment 3;

4 is the detection of the in-situ distribution and content of fibroin in the composite silk product in Example 4.

Detailed ways

The present invention will be further described in detail by the following examples. The following examples are to explain the present invention and the present invention is not limited to the following examples.

Embodiments of the present invention are as follows:

Example 1:

(1) Single-point scanning of the silk fiber standard using a visual laser Raman spectrometer to obtain the Raman map of the silk protein standard. Scanning parameter setting: laser power 1mW, exposure time 10Hz, scanning times 100 times, pixel 0.5μm, total scanning time 20 seconds.

(2) Smoothing, adjusting the baseline and standardizing the Raman spectrum of step (1) to obtain all peaks and strong characteristic peaks of the silk protein standard product. As shown in Figure 1, the peaks of the silk standard spectrum contain 3058-3062cm ^-1 , 2932-2936cm ^-1 , 2875-2880cm ^-1 , 1662-1668cm-1, 1446-1452cm ^-1 , 1228-1231cm ^-1 , 1082cm ^-1 Peaks such as -1086cm ^-1 and 851-855cm ^-1 , among which the strong characteristic peaks are 3058-3062cm ^-1 , 1662-1668cm ^-1 , 1446-1452cm ^-1 , 1228-1231cm ^-1 , 1082-1086cm ^-1 .

(3) Single-point scanning of the silk fabric to be tested using a visual laser Raman spectrometer to obtain a Raman spectrum of the silk fabric to be tested. Scanning parameter setting: laser power 8mW, exposure time 100Hz, scanning times 1, pixel 2μm, total scanning time is about 5 seconds.

(4) comparing the Raman spectrum of step (1) with the standard spectrum of silk, without the need for complex data analysis, to identify whether the substance to be identified is a silk product. As shown in Figure 2, the identification of various fabrics such as polyvinyl fluoride fiber, chitosan fiber, cotton fiber, etc., it is found that the peak value, peak height, peak width, peak area in the standard spectrum of silk are related to polyvinyl fluoride fiber, shell The peak value, peak height, peak width and peak area of various silk fabrics such as polysaccharide fiber and cotton fiber are different, which can distinguish silk fabrics from other types of silk fabrics.

Example 2:

Steps (1) and (2) in Example 1 above were used.

(3) Single-point scanning of silk products such as fibroin fibers, silk fabrics and silk fibroin powder using a visual laser Raman spectrometer to obtain a Raman spectrum of the fiber material to be tested.

Scanning parameter setting: laser power 4mW, exposure time 1Hz, scanning times 300 times, pixel 0.2μm, total scanning time about 30 seconds.

(4) The Raman spectra obtained in step (1) are compared with each other. As shown in Figure 3: the characteristic peaks, peak heights, peak widths and peak areas of silk protein fibers, silk products and silk fibroin powder are similar, so it can be seen that the Raman spectra of silk protein in different states are consistent and have the same molecule consistency.

Example 3:

Steps (1) and (2) in Example 1 above were used.

(3) In-situ surface scanning of the fiber to be tested is performed using a visual laser confocal Raman spectrometer to obtain a Raman two-dimensional image of the fiber to be tested in a certain area (manually selected). Scanning parameter setting: laser power 4mW, exposure time 5Hz, scanning times 50 times, pixel 1.5μm, total scanning time 30 minutes.

(4) Compare and reduce the Raman two-dimensional image in step (1) with the silk standard atlas, and quickly measure the silk content and distribution in the fibrous material to be tested by the MCR of the Raman spectrometer, and find that the fibrous material to be tested is found. It has obvious Raman peak spectrum of silk protein and polyethylene glycol (PEG) Raman peak spectrum. Among them, fibroin is evenly distributed in the fibrous test product, accounting for about 79.2% of the fiber test product, while PEG accounts for 14.3% of the fiber test product, and the rest are other substances.

Compared with traditional Raman spectrometers, confocal laser Raman spectrometers have confocal imaging capabilities and integrate OMNIC Atlμs image processing software, which can map micron-level resolution spectra, and integrate image analysis algorithms and chemometric tools.

The MCR processing process of this embodiment is as follows: first, a confocal laser Raman spectrometer is used to image a selected area of the silk protein sample, a laser scanning beam is used to form a point light source through a grating pinhole, and the focal plane is scanned point by point to obtain a high-definition image. With high-resolution nanoscale multi-point Raman spectrum, one point represents a peak; then use the OMNIC Atlμs image software to calculate the second derivative of each Raman spectrum peak, divide it into multiple peaks, and perform according to the peak. Quantification of a Raman spectrum is completed by calculation. When all Raman spectra of a specific area are scanned, the quantitative information of all silk protein-containing substances is obtained.

According to the identification results of Examples 1, 2 and 3, it can be seen that whether different substances to be detected are silk fibroin can be accurately identified by using the laser Raman spectroscopy technology proposed in this application. According to the analysis results of Example 4, it can be seen that the distribution and content of silk fibroin in the complex can be accurately identified by using the laser Raman spectroscopy technique proposed in the present application, with high resolution. Therefore, a method for rapid and non-destructive identification of silk products and their content proposed in this application can accurately analyze whether there is silk protein in the object to be tested, and can also quantitatively analyze the silk in the object to be tested, and is fast, simple, and non-destructive. , efficient and repeatable advantages are very significant.

Claims (4)

1. A method for rapidly and nondestructively identifying silk products and content is characterized by comprising the following steps:

1) performing single-point scanning on the quasi-appraisal object by using a visual laser Raman spectrometer to obtain a single or a series of Raman spectrums;

2) comparing the Raman spectrum obtained in the step 1) with a silk standard spectrum to identify whether the quasi-identification substance is a silk product;

the peak value range of the silk standard map in the step 2) contains 3058-3062cm^-1、2932-2936cm^-1、2875-2880cm^-1、1662-1668cm^-1、1446-1452cm^-1、1228-1231cm^-1、1081-1086cm^-1、851-855cm^-1Wherein the range of the strong characteristic peak is 3058-3062cm^-1、1662-1668cm^-1、1446-1452cm^-1、1228-1231cm^-1、1081-1086cm^-1(ii) a If at least four peak values in different peak value ranges of the silk standard map or at least three peak values in different strong characteristic peak value ranges of the silk standard map appear in the Raman map obtained in the step 1), judging that the quasi-identification object is a silk product or a silk-containing raw material;

comparing the Raman spectrum of the quasi-identifier with the silk standard spectrum and reducing and determining the content of silk in the quasi-identifier; firstly, a selected area of a silk fibroin sample is imaged by using a confocal laser Raman spectrometer, a laser scanning beam is used for forming a point light source through a grating pinhole, point-by-point scanning is carried out on a focal plane, and a high-definition and high-resolution nanoscale multipoint Raman spectrum is obtained, wherein one point represents a peak value; and then, performing second derivative calculation on each Raman spectrum peak value by using OMNIC Atl mu s image software, dividing the Raman spectrum peak value into a plurality of peaks, performing calculation according to the peak values to finish the quantification of one Raman spectrum, and obtaining the quantitative information of all the fibroin-containing substances after all the Raman spectrums in a specific area are scanned.

2. The method for rapid and non-destructive identification of silk products and silk content as claimed in claim 1, wherein: the silk standard spectrum in the step 2) is obtained by reeling silk on the spun silkworm cocoons to obtain silk fibers, and placing the silk fibers in a Raman spectrometer for testing.

3. The method for rapid and non-destructive identification of silk products and silk content as claimed in claim 1, wherein: the scanning parameters during scanning are set as follows: laser power is 1-8mW, exposure time is 1-100Hz, scanning times are 1-300 times, and pixels are 0.2-2 μm.

4. The method for rapid and non-destructive identification of silk products and silk content as claimed in claim 1, wherein: the quasi-identification object in the step 2) comprises silk fabrics, silk cultural relics, silk materials and silk artworks.

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