A method for rapid identification of formaldehyde positive samples in textiles by color development

Abstract

The present application relates to the technical field of textile detection, and particularly relates to a method for rapidly identifying formaldehyde positive samples in textiles by color development method, which extracts the textiles by using an activator solution, and forms a sample activation solution by heating reaction, so as to shorten the pretreatment time, and the detection cycle of the present application can be controlled within 10 minutes, which is significantly shorter than the detection cycle of about 2 hours of the current formaldehyde test method GB / T 2912.1-2009 in textiles. The color development condition of the color development stick can be directly used to visually judge whether the formaldehyde result is positive or not, without the need of specific detection instruments, and the detection limit can be reduced to 5 mg / kg. Therefore, the method is convenient to operate, high in sensitivity, reliable in result, not easy to be disturbed by external environment, can rapidly identify formaldehyde positive samples by visual colorimetric method, can significantly shorten the test time, reduce the detection limit of color development, and reduce the risk of screening failure.

Description

Technical Field

[0001] This invention relates to the field of textile testing technology, specifically to a method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method. Background Technology

[0002] Formaldehyde content in textiles is one of the mandatory testing items stipulated in the national mandatory standard GB 18401-2010, "National Basic Safety Technical Specifications for Textile Products". With the increasing environmental and safety awareness of my country's textile, dyeing, and garment industries, and the implementation of strategies to actively develop and use environmentally friendly dyes and auxiliaries, the quality of my country's export products and their competitiveness in the international market have greatly improved, and the detection rate of formaldehyde and other harmful substances has gradually decreased. In recent years, the actual formaldehyde detection rate in textiles and leather has been less than 5%. Given the current situation, developing simple, rapid, and low-cost screening methods that do not rely on testing instruments is of great value in formaldehyde detection.

[0003] Currently available rapid formaldehyde detection methods mainly include simple electronic detectors, colorimetric-spectrophotometric methods, gas (liquid) chromatography-mass spectrometry, fluorescence spectrometry, and electrochemical sensor detection methods. Among these, electronic detectors, fluorescence spectrometry, and electrochemical sensor detection methods are easily affected by external environmental interference, resulting in unstable readings, and are therefore not currently used by professional testing institutions. Furthermore, gas (liquid) chromatography is cumbersome to operate and has high instrument costs, making it less commonly used for formaldehyde detection.

[0004] In the prior art, Chinese patent application No. 201822277491.0 discloses a rapid detection system for formaldehyde content in textiles, which detects formaldehyde by directly reacting the textile with a display, but it can only detect samples with a formaldehyde content of 30 ppm or higher. Additionally, Chinese patent application No. 201710123529.6 discloses a rapid formaldehyde detection method where the sample extract is displayed on the instrument for testing, overcoming the shortcomings of previous methods such as cumbersome pretreatment procedures, expensive testing instruments, and the inability to standardize testing methods for different products. Chinese patent application No. 202011417547.3 discloses a test strip and detection method for formaldehyde content in textiles, which includes formaldehyde test strips and a colorimetric card for comparison with the formaldehyde test strips. Chinese patent application No. 201811573691.9 discloses a rapid-response formaldehyde fluorescent probe, its preparation method, and its application. This probe enables rapid and non-destructive detection of formaldehyde in aqueous solutions, with a detection limit of 5 × 10⁻⁶ mol / L. However, the existing technology still needs further improvement in methanol detection methods. Specifically, the sample extraction and colorimetric procedures need further optimization to improve colorimetric efficiency and sensitivity, meeting the requirement of GB 18401-2010 "National Basic Safety Technical Specifications for Textile Products" that the formaldehyde content of Class A products must not exceed 20 mg / kg. Therefore, developing a more accurate, rapid, and sensitive formaldehyde colorimetric screening method is of significant practical importance. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention aims to provide a method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method. This method is convenient to operate, highly sensitive, and provides reliable results. It is not easily affected by external environmental interference, can rapidly identify formaldehyde-positive samples through visual colorimetry, and can significantly shorten the testing time, reduce the detection limit of colorimetry, and reduce the risk of missed screening.

[0006] To achieve the objectives of the invention described above, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method, comprising the following steps:

[0008] S1. Sample preparation: Cut the textile into pieces to obtain the sample;

[0009] S2. Sample activation: Place the sample in a container, then add an activator solution to the container, stir or shake the container to immerse the sample in the activator solution, and then place the container in a constant temperature water bath to react and form a sample activation solution.

[0010] S3. Color development: Remove the container from the constant temperature water bath, then insert the color development rod into the sample activation solution. After the sample activation solution is completely absorbed by the color development rod, remove the color development rod and observe the color change of the color development rod.

[0011] S4. Blank test: Use pure water instead of the activator solution in step S2, and perform the test according to steps S2 and S3.

[0012] S5. Identification and Judgment: The color development of the activator solution test and the blank test is compared. If no obvious color change occurs after the color development bar develops the color, it means that the sample does not contain formaldehyde or its concentration is below the detection limit, which is a formaldehyde-negative sample. If an obvious color change occurs after color development, it means that the sample contains formaldehyde, which is a formaldehyde-positive sample.

[0013] Furthermore, in step S1, the size of the fragment is (3~8) mm × (3~8) mm.

[0014] Furthermore, in step S2, the activator solution is an aqueous solution of the phenol reagent MBTH; and / or

[0015] The concentration of the phenol reagent MBTH is 0.001 g / mL to 0.003 g / mL.

[0016] Furthermore, in step S2, the temperature of the constant temperature water bath is 78℃~82℃; and / or

[0017] The reaction time is 1.5 min to 2.5 min.

[0018] Furthermore, in step S2, the container is a glass tube.

[0019] Furthermore, in step S3, the colorimetric bar includes a main tube and a colorimetric column core disposed at the bottom of the inner cavity of the main tube. The colorimetric column core includes a transparent tube and absorbent cotton wool filled in the transparent tube; and / or

[0020] The colorimetric reagent includes ferric sulfate and aminosulfonic acid; and / or

[0021] The absorbent cotton soaked in the colorimetric reagent fills the transparent tube to a height of 45mm~55mm; and / or

[0022] The inner diameter of the transparent tube is 10mm~14mm.

[0023] Furthermore, the main body tube includes a handle portion and an observation window located below the handle portion;

[0024] The color-developing column is positioned at the location corresponding to the observation window.

[0025] Furthermore, the upper part of the inner cavity of the main tube is provided with a cavity for storing the activator;

[0026] The top of the cavity is provided with a nut for sealing the cavity. When a colorimetric method is needed for rapid identification of formaldehyde-positive samples in textiles, the nut is unscrewed, and the activator in the cavity is poured out to prepare the activator solution in step S2 above.

[0027] Furthermore, the method for preparing the absorbent cotton adsorbed with the colorimetric reagent is as follows: after adsorbing the absorbent cotton with a mixed solution of ferric sulfate and sulfamic acid, it is dried in an oven to obtain absorbent cotton adsorbed with the colorimetric reagent; and / or

[0028] The mass-to-volume ratio of the absorbent cotton to the mixed solution is (0.5~1.0) g:(1~3) mL; and / or

[0029] The drying temperature is 55℃~65℃, and the drying time is 20h~24h; and / or

[0030] The mixed solution of ferric sulfate and sulfamic acid was prepared as follows: Weigh 14.7g of ferric sulfate and 125g of sulfamic acid, dissolve them in water, and prepare a 500mL solution.

[0031] Furthermore, in step S3, the color developing bar is removed, and the color change of the color developing bar is observed after 50s to 70s.

[0032] Among them, the present invention provides a method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method. The colorimetric principle is as follows: formaldehyde in textiles reacts with an activator (phenol reagent MBTH) during heating to generate a azine compound. Then, by inserting a colorimetric rod, the azine compound reacts with iron ions under acidic conditions to produce a blue-green color.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] (1) The present invention provides a method for rapid identification of formaldehyde-positive samples in textiles by colorimetric method. The textiles are extracted with an activator solution and a sample activation solution is formed by heating reaction. Compared with the standard test method GB / T 2912.1-2009 of the prior art, the present invention can shorten the extraction time from 1 hour to 1.5 min to 2.5 min. In addition, by directly inserting the colorimetric rod into the sample activation solution for adsorption and color development, the activator and colorimetric reagent are integrated in the colorimetric rod. There is no need to transfer the solution during the detection process, which improves the portability of the detection. Therefore, compared with the prior art, the present invention does not require the use of pipettes or other equipment to transfer the extract, and has the advantages of being convenient, fast and obvious in color development.

[0035] (2) The present invention provides a method for rapid identification of formaldehyde-positive samples in textiles by colorimetric method. By integrating the traditional extraction process and optimizing the test conditions, the sample is directly extracted with an activator solution and subjected to a heating reaction, thereby shortening the pretreatment time. Compared with the detection cycle of the current formaldehyde test method GB / T 2912.1-2009 in textiles, which is about 2 hours, the detection cycle of the present invention can be controlled within 10 minutes, which significantly shortens the test time and has the advantage of short test time.

[0036] (3) The present invention provides a method for rapid identification of formaldehyde-positive samples in textiles by colorimetric method. It can directly judge whether the formaldehyde result is positive by visually observing the color development of the colorimetric bar. No specific detection instrument is required. It has the advantages of low detection cost, fast detection and convenient operation.

[0037] (4) The colorimetric method of the present invention for rapid identification of formaldehyde-positive samples in textiles has a detection limit of 5 mg / kg, compared to the detection limit of 20 mg / kg in the current formaldehyde testing method GB / T 2912.1-2009. Therefore, the present invention can reduce the detection limit of colorimetric methods, thereby reducing the risk of missed screening. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the exploded structure of the colorimetric bar used in the method for rapid identification of formaldehyde-positive samples in textiles according to the present invention.

[0039] Figure 2 This is a schematic diagram of the sample color development process for a method of rapid identification of formaldehyde-positive samples in textiles using a colorimetric method according to the present invention.

[0040] Figure 3 This is a display image showing the process before and after color development using a colorimetric bar in a method for rapid identification of formaldehyde-positive samples in textiles according to the present invention.

[0041] Figure label:

[0042] 1. Nut; 2. Cavity for storing activator; 3. Handle; 4. Developing column core; 5. Observation window; 6. Transparent tube; 7. Degreased cotton soaked in developing reagent. Detailed Implementation

[0043] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0044] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. In this invention, the singular forms “a,” “the,” and “the” as used in the embodiments and appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0045] The chemical name of the phenol reagent MBTH mentioned in this invention is 3-methyl-2-benzothiazolinone hydrazone hydrochloride.

[0046] The following description is based on specific embodiments.

[0047] Example 1

[0048] A colorimetric method for rapid identification of formaldehyde-positive samples in textiles is available for reference. Figures 1 to 3 This includes the following steps:

[0049] S1. Sample preparation: Cut the textile into pieces to obtain the sample; in this embodiment, the size of the pieces is 5mm x 5mm.

[0050] S2. Sample activation: Place the sample in a glass tube, then add the extraction solution and an aqueous solution of the phenol reagent MBTH to the glass tube. Stir or shake the glass tube to immerse the sample in the mixed solution formed by the extraction solution and the activator solution. Then place the glass tube in an 80°C constant temperature water bath for 2 minutes to form a sample activation solution. In this example, the concentration of the aqueous solution of the phenol reagent MBTH is 0.002 g / mL.

[0051] S3. Color development: Remove the glass tube from the constant temperature water bath, then insert the color development rod into the sample activation solution. After the sample activation solution is completely absorbed by the color development rod, remove the color development rod and observe the color change of the color development rod after 60 seconds.

[0052] Among them, such as Figure 1 As shown, the colorimetric bar includes a main tube and a colorimetric column core 4 disposed at the bottom of the inner cavity of the main tube. The colorimetric column core 4 includes a transparent tube 6 and degreased cotton 7 filled with colorimetric reagent in the transparent tube 6. The colorimetric reagent includes ferric sulfate and sulfamic acid. In this embodiment, the filling height of the degreased cotton 7 with colorimetric reagent in the transparent tube 4 is 50 mm. In this embodiment, the inner diameter of the transparent tube 4 is 12 mm.

[0053] The main tube includes a handle part 4 and an observation window 5 located below the handle part 3; the color developing column core 4 is located at the position corresponding to the observation window 5.

[0054] The main tube has a cavity 2 for storing activator in the upper part of its inner cavity; and a nut 1 for sealing the cavity 2 is provided on the top of the cavity 2 for storing activator.

[0055] The method for preparing the absorbent cotton 7 with the colorimetric reagent is as follows: after the absorbent cotton absorbs a mixed solution of ferric sulfate and sulfamic acid, it is dried in an oven at 60°C for 22 hours to obtain the absorbent cotton with the colorimetric reagent. In this embodiment, the mass-to-volume ratio of absorbent cotton to the mixed solution is 0.8 g: 2 mL.

[0056] The mixed solution of ferric sulfate and sulfamic acid is prepared as follows: Weigh 14.7g of ferric sulfate and 125g of sulfamic acid, dissolve them in water, and prepare a 500mL solution.

[0057] S4. Blank test: Use pure water instead of the aqueous solution of MBTH phenol reagent in step S2, and perform the test according to steps S2 and S3.

[0058] S5. Identification and Judgment: The color development of the activator solution test and the blank test is compared. If no obvious color change occurs after the color development bar develops the color, it means that the sample does not contain formaldehyde or its concentration is below the detection limit, which is a formaldehyde-negative sample. If an obvious color change occurs after color development, it means that the sample contains formaldehyde, which is a formaldehyde-positive sample.

[0059] Example 2

[0060] A colorimetric method for rapid identification of formaldehyde-positive samples in textiles is available for reference. Figures 1 to 3 This includes the following steps:

[0061] S1. Sample preparation: Cut the textile into pieces to obtain the sample; in this embodiment, the size of the pieces is 3mm x 3mm.

[0062] S2. Sample Activation: Place the sample in a glass tube, then add the extraction solution and an aqueous solution of the phenol reagent MBTH to the glass tube. Stir or shake the glass tube to immerse the sample in the mixed solution formed by the extraction solution and the activator solution. Then place the glass tube in a 78°C constant temperature water bath for 2.5 min to form a sample activation solution. In this example, the concentration of the aqueous solution of the phenol reagent MBTH is 0.001 g / mL.

[0063] S3. Color development: Remove the glass tube from the constant temperature water bath, then insert the color development rod into the sample activation solution. After the sample activation solution is completely absorbed by the color development rod, remove the color development rod and observe the color change of the color development rod after 50 seconds.

[0064] Among them, such as Figure 1As shown, the colorimetric bar includes a main tube and a colorimetric column core 4 disposed at the bottom of the inner cavity of the main tube. The colorimetric column core 4 includes a transparent tube 6 and degreased cotton 7 filled with colorimetric reagent in the transparent tube 6. The colorimetric reagent includes ferric sulfate and sulfamic acid. In this embodiment, the filling height of the degreased cotton 7 with colorimetric reagent in the transparent tube 4 is 45 mm. In this embodiment, the inner diameter of the transparent tube 4 is 10 mm.

[0065] The main tube includes a handle part 4 and an observation window 5 located below the handle part 3; the color developing column core 4 is located at the position corresponding to the observation window 5.

[0066] The main tube has a cavity 2 for storing activator in the upper part of its inner cavity; and a nut 1 for sealing the cavity 2 is provided on the top of the cavity 2 for storing activator.

[0067] The method for preparing the absorbent cotton 7 with the colorimetric reagent is as follows: after the absorbent cotton absorbs a mixed solution of ferric sulfate and sulfamic acid, it is dried in an oven at 55°C for 24 hours to obtain the absorbent cotton with the colorimetric reagent. In this embodiment, the mass-to-volume ratio of absorbent cotton to the mixed solution is 0.5 g: 1 mL.

[0068] The mixed solution of ferric sulfate and sulfamic acid is prepared as follows: Weigh 14.7g of ferric sulfate and 125g of sulfamic acid, dissolve them in water, and prepare a 500mL solution.

[0069] S4. Blank test: Use pure water instead of the aqueous solution of MBTH phenol reagent in step S2, and perform the test according to steps S2 and S3.

[0070] S5. Identification and Judgment: The color development of the activator solution test and the blank test is compared. If no obvious color change occurs after the color development bar develops the color, it means that the sample does not contain formaldehyde or its concentration is below the detection limit, which is a formaldehyde-negative sample. If an obvious color change occurs after color development, it means that the sample contains formaldehyde, which is a formaldehyde-positive sample.

[0071] Example 3

[0072] A colorimetric method for rapid identification of formaldehyde-positive samples in textiles is available for reference. Figures 1 to 3 This includes the following steps:

[0073] S1. Sample preparation: Cut the textile into pieces to obtain the sample; in this embodiment, the size of the piece is 8mm x 8mm.

[0074] S2. Sample Activation: Place the sample in a glass tube, then add the extraction solution and an aqueous solution of the phenol reagent MBTH to the glass tube. Stir or shake the glass tube to immerse the sample in the mixed solution formed by the extraction solution and the activator solution. Then place the glass tube in an 82°C constant temperature water bath for 1.5 min to form a sample activation solution. In this example, the concentration of the aqueous solution of the phenol reagent MBTH is 0.003 g / mL.

[0075] S3. Color development: Remove the glass tube from the constant temperature water bath, then insert the color development rod into the sample activation solution. After the sample activation solution is completely absorbed by the color development rod, remove the color development rod and observe the color change of the color development rod after 70 seconds.

[0076] Among them, such as Figure 1 As shown, the colorimetric bar includes a main tube and a colorimetric column core 4 disposed at the bottom of the inner cavity of the main tube. The colorimetric column core 4 includes a transparent tube 6 and degreased cotton 7 filled with colorimetric reagent in the transparent tube 6. The colorimetric reagent includes ferric sulfate and sulfamic acid. In this embodiment, the filling height of the degreased cotton 7 with colorimetric reagent in the transparent tube 4 is 55 mm. In this embodiment, the inner diameter of the transparent tube 4 is 14 mm.

[0077] The main tube includes a handle part 4 and an observation window 5 located below the handle part 3; the color developing column core 4 is located at the position corresponding to the observation window 5.

[0078] The main tube has a cavity 2 for storing activator in the upper part of its inner cavity; and a nut 1 for sealing the cavity 2 is provided on the top of the cavity 2 for storing activator.

[0079] The method for preparing the absorbent cotton 7 with the colorimetric reagent is as follows: after the absorbent cotton absorbs a mixed solution of ferric sulfate and sulfamic acid, it is dried in an oven at 65°C for 20 hours to obtain the absorbent cotton with the colorimetric reagent. In this embodiment, the mass-to-volume ratio of absorbent cotton to the mixed solution is 1.0 g: 3 mL.

[0080] The mixed solution of ferric sulfate and sulfamic acid is prepared as follows: Weigh 14.7g of ferric sulfate and 125g of sulfamic acid, dissolve them in water, and prepare a 500mL solution.

[0081] S4. Blank test: Use pure water instead of the aqueous solution of MBTH phenol reagent in step S2, and perform the test according to steps S2 and S3.

[0082] S5. Identification and Judgment: The color development of the activator solution test and the blank test is compared. If no obvious color change occurs after the color development bar develops the color, it means that the sample does not contain formaldehyde or its concentration is below the detection limit, which is a formaldehyde-negative sample. If an obvious color change occurs after color development, it means that the sample contains formaldehyde, which is a formaldehyde-positive sample.

[0083] Example 4

[0084] A colorimetric method for rapid identification of formaldehyde-positive samples in textiles is available for reference. Figures 1 to 3 This includes the following steps:

[0085] S1. Sample preparation: Cut the textile into pieces to obtain the sample; in this embodiment, the size of the pieces is 4mm x 6mm.

[0086] S2. Sample Activation: Place the sample in a glass tube, then add the extraction solution and an aqueous solution of the phenol reagent MBTH to the glass tube. Stir or shake the glass tube to immerse the sample in the mixed solution formed by the extraction solution and the activator solution. Then place the glass tube in a 79°C constant temperature water bath for 2.2 min to form a sample activation solution. In this example, the concentration of the aqueous solution of the phenol reagent MBTH is 0.002 g / mL.

[0087] S3. Color development: Remove the glass tube from the constant temperature water bath, then insert the color development rod into the sample activation solution. After the sample activation solution is completely absorbed by the color development rod, remove the color development rod and observe the color change of the color development rod after 55 seconds.

[0088] Among them, such as Figure 1 As shown, the colorimetric bar includes a main tube and a colorimetric column core 4 disposed at the bottom of the inner cavity of the main tube. The colorimetric column core 4 includes a transparent tube 6 and degreased cotton 7 filled with colorimetric reagent in the transparent tube 6. The colorimetric reagent includes ferric sulfate and sulfamic acid. In this embodiment, the filling height of the degreased cotton 7 with colorimetric reagent in the transparent tube 4 is 48 mm. In this embodiment, the inner diameter of the transparent tube 4 is 11 mm.

[0089] The main tube includes a handle part 4 and an observation window 5 located below the handle part 3; the color developing column core 4 is located at the position corresponding to the observation window 5.

[0090] The main tube has a cavity 2 for storing activator in the upper part of its inner cavity; and a nut 1 for sealing the cavity 2 is provided on the top of the cavity 2 for storing activator.

[0091] The method for preparing the absorbent cotton 7 with the colorimetric reagent is as follows: after the absorbent cotton absorbs a mixed solution of ferric sulfate and sulfamic acid, it is dried in an oven at 58°C for 23 hours to obtain the absorbent cotton with the colorimetric reagent. In this embodiment, the mass-to-volume ratio of absorbent cotton to the mixed solution is 0.6 g: 1.5 mL.

[0092] The mixed solution of ferric sulfate and sulfamic acid is prepared as follows: Weigh 14.7g of ferric sulfate and 125g of sulfamic acid, dissolve them in water, and prepare a 500mL solution.

[0093] S4. Blank test: Use pure water instead of the aqueous solution of MBTH phenol reagent in step S2, and perform the test according to steps S2 and S3.

[0094] S5. Identification and Judgment: The color development of the activator solution test and the blank test is compared. If no obvious color change occurs after the color development bar develops the color, it means that the sample does not contain formaldehyde or its concentration is below the detection limit, which is a formaldehyde-negative sample. If an obvious color change occurs after color development, it means that the sample contains formaldehyde, which is a formaldehyde-positive sample.

[0095] Example 5

[0096] A colorimetric method for rapid identification of formaldehyde-positive samples in textiles is available for reference. Figures 1 to 3 This includes the following steps:

[0097] S1. Sample preparation: Cut the textile into pieces to obtain the sample; in this embodiment, the size of the piece is 7mm x 4mm.

[0098] S2. Sample Activation: Place the sample in a glass tube, then add the extraction solution and an aqueous solution of the phenol reagent MBTH to the glass tube. Stir or shake the glass tube to immerse the sample in the mixed solution formed by the extraction solution and the activator solution. Then place the glass tube in an 81°C constant temperature water bath for 1.8 min to form a sample activation solution. In this example, the concentration of the aqueous solution of the phenol reagent MBTH is 0.002 g / mL.

[0099] S3. Color development: Remove the glass tube from the constant temperature water bath, then insert the color development rod into the sample activation solution. After the sample activation solution is completely absorbed by the color development rod, remove the color development rod and observe the color change of the color development rod after 65 seconds.

[0100] Among them, such as Figure 1 As shown, the colorimetric bar includes a main tube and a colorimetric column core 4 disposed at the bottom of the inner cavity of the main tube. The colorimetric column core 4 includes a transparent tube 6 and degreased cotton 7 filled with colorimetric reagent in the transparent tube 6. The colorimetric reagent includes ferric sulfate and sulfamic acid. In this embodiment, the filling height of the degreased cotton 7 with colorimetric reagent in the transparent tube 4 is 52 mm. In this embodiment, the inner diameter of the transparent tube 4 is 13 mm.

[0101] The main tube includes a handle part 4 and an observation window 5 located below the handle part 3; the color developing column core 4 is located at the position corresponding to the observation window 5.

[0102] The main tube has a cavity 2 for storing activator in the upper part of its inner cavity; and a nut 1 for sealing the cavity 2 is provided on the top of the cavity 2 for storing activator.

[0103] The method for preparing the absorbent cotton 7 with the colorimetric reagent is as follows: after the absorbent cotton absorbs a mixed solution of ferric sulfate and sulfamic acid, it is dried in an oven at 63°C for 21 hours to obtain the absorbent cotton with the colorimetric reagent. In this embodiment, the mass-to-volume ratio of absorbent cotton to the mixed solution is 0.9 g: 2.5 mL.

[0104] The mixed solution of ferric sulfate and sulfamic acid is prepared as follows: Weigh 14.7g of ferric sulfate and 125g of sulfamic acid, dissolve them in water, and prepare a 500mL solution.

[0105] S4. Blank test: Use pure water instead of the aqueous solution of MBTH phenol reagent in step S2, and perform the test according to steps S2 and S3.

[0106] S5. Identification and Judgment: The color development of the activator solution test and the blank test is compared. If no obvious color change occurs after the color development bar develops the color, it means that the sample does not contain formaldehyde or its concentration is below the detection limit, which is a formaldehyde-negative sample. If an obvious color change occurs after color development, it means that the sample contains formaldehyde, which is a formaldehyde-positive sample.

[0107] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method, characterized in that, Includes the following steps: S1. Sample preparation: Cut the textile into pieces to obtain the sample; S2. Sample activation: Place the sample in a container, then add an activator solution to the container, stir or shake the container to immerse the sample in the activator solution, and then place the container in a constant temperature water bath to react and form a sample activation solution. S3. Color development: Remove the container from the constant temperature water bath, then insert the color development rod into the sample activation solution. After the sample activation solution is completely absorbed by the color development rod, remove the color development rod and observe the color change of the color development rod. S4. Blank test: Use pure water instead of the activator solution in step S2, and perform the test according to steps S2 and S3. S5. Identification and Judgment: The color development of the activator solution test and the blank test is compared. If no obvious color change occurs after the color development bar develops the color, it means that the sample does not contain formaldehyde or its concentration is below the detection limit, which is a formaldehyde-negative sample. If an obvious color change occurs after color development, it means that the sample contains formaldehyde, which is a formaldehyde-positive sample.

2. The method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method as described in claim 1, characterized in that, In step S1, the size of the fragment is (3~8) mm × (3~8) mm.

3. The method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method as described in claim 1, characterized in that, In step S2, the activator solution is an aqueous solution of the phenol reagent MBTH; and / or The concentration of the phenol reagent MBTH is 0.001 g / mL to 0.003 g / mL.

4. The method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method as described in claim 1, characterized in that, In step S2, the temperature of the constant temperature water bath is 78℃~82℃; and / or The reaction time is 1.5 min to 2.5 min.

5. The method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method as described in claim 1, characterized in that, In step S2, the container is a glass tube.

6. The method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method as described in claim 1, characterized in that, In step S3, the colorimetric bar includes a main tube and a colorimetric column core disposed at the bottom of the inner cavity of the main tube. The colorimetric column core includes a transparent tube and absorbent cotton wool filled with colorimetric reagent in the transparent tube; and / or The colorimetric reagent includes ferric sulfate and aminosulfonic acid; and / or The absorbent cotton soaked in the colorimetric reagent fills the transparent tube to a height of 45mm~55mm; and / or The inner diameter of the transparent tube is 10mm~14mm.

7. The method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method as described in claim 6, characterized in that, The main tube includes a handle portion and an observation window located below the handle portion; The color-developing column core is positioned at the location corresponding to the observation window.

8. The method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method as described in claim 7, characterized in that, The upper part of the inner cavity of the main tube is provided with a cavity for storing activator; The top of the cavity is provided with a nut for sealing the cavity.

9. The method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method as described in claim 6, characterized in that, The method for preparing the absorbent cotton adsorbed with the colorimetric reagent is as follows: after the absorbent cotton adsorbs a mixed solution of ferric sulfate and sulfamic acid, it is dried in an oven to obtain absorbent cotton adsorbed with the colorimetric reagent; and / or The mass-to-volume ratio of the absorbent cotton to the mixed solution is (0.5~1.0) g:(1~3) mL; and / or The drying temperature is 55℃~65℃, and the drying time is 20h~24h; and / or The mixed solution of ferric sulfate and sulfamic acid was prepared as follows: Weigh 14.7g of ferric sulfate and 125g of sulfamic acid, dissolve them in water, and prepare a 500mL solution.

10. The method for rapid identification of formaldehyde-positive samples in textiles using a colorimetric method as described in claim 1, characterized in that, In step S3, remove the color developing bar and observe the color change of the color developing bar after 50s to 70s.

Images