A rapid screening method for the determination of formaldehyde in textiles

Abstract

The present invention discloses a rapid screening method for the determination of formaldehyde in textiles. Compared with the existing test methods, the formaldehyde rapid screening method provided by the present invention samples and tests a small number of samples with strong representativeness, facilitating the rapid precipitation of formaldehyde from the samples. At the same time, by adding a reaction solvent before heating, the precipitation efficiency of formaldehyde can be improved during the heating process, and the reaction efficiency between formaldehyde and the reaction solvent can be catalytically enhanced, thereby effectively improving the determination efficiency of formaldehyde content. The detection process that originally took 120 - 150 minutes in the prior art can be compressed to within 10 minutes to complete the overall detection, greatly improving the detection efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of textile component detection, and particularly relates to a rapid screening method for the determination of formaldehyde in textiles. Background Art

[0002] Formaldehyde is an organic compound that is highly harmful to the human body. At low concentrations, it is not easily detectable and can easily be masked by other odors, such as air fresheners. At higher concentrations, it has a strong pungent and asphyxiating odor and can irritate the human eyes, nose, etc. Formaldehyde is currently a toxic gas that seriously endangers human health and is more commonly found in substandard furniture and building materials. Long-term exposure to a high concentration of formaldehyde can cause symptoms such as dizziness, headache, tearing, nausea, vomiting, cough, chest tightness, and leukemia in patients, and in severe cases, it can lead to death. In the process of fabric processing, formaldehyde is often involved. For example, using reactive resins containing formaldehyde can make the fabric smoother, the color of fabrics containing formaldehyde will be more vivid, and printing materials also contain formaldehyde. Since the ready-to-wear clothes made of fabrics are worn close to the body, if the formaldehyde content exceeds the standard, it is likely to cause serious harm to the human body. Therefore, it is generally necessary to determine the formaldehyde content of textiles. The existing determination of formaldehyde in textiles is carried out according to the standard process of "GB / T 2912.1-2009 Determination of Formaldehyde in Textiles". First, two parallel samples are weighed, 1 g of each sample is taken and placed in an extraction container, 100 ml of water is added to the container, and extraction is carried out at a water temperature of 40°C for 30 min. After filtering the extraction solution, 5 ml of the extraction solution is taken and 5 ml of acetylacetone solution is added for color development for 30 min. After cooling at room temperature for 30 min, the absorbance of the color-developed solution is measured with a spectrophotometer, and the formaldehyde content in the sample fabric is calculated.

[0003] Although this method can measure the formaldehyde content in textiles, the detection time for each group of samples requires about 2 hours, which takes a relatively long time and has a greater impact on the overall detection efficiency.

[0004] Therefore, there are deficiencies in the existing technology and it needs to be improved. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the existing technology and provide a rapid screening method for the determination of formaldehyde in textiles.

[0006] The technical solution of the present invention is as follows: A rapid screening method for the determination of formaldehyde in textiles is provided, including the following steps:

[0007] Step 1: Take two specimens cut into pieces from the same sample, weigh 0.1 g of each specimen and place them in a container respectively;

[0008] Step 2: Add 10 ml of reaction solution to the container containing the test sample, and carry out the reaction in a water bath at 70 ± 2 °C for 5 min. At the same time, add the control protective solution to the container containing the blank comparison sample and carry out the reaction in the same environment.

[0009] Step 3: After the reaction is completed, quickly cool the sample solution to room temperature.

[0010] Step 4: Filter the cooled sample solution.

[0011] Step 5: Take appropriate amounts of the sample solution from the filtrate into a spectrophotometer, measure the absorbance of formaldehyde in the sample solution, and calculate the content of free formaldehyde in the sample by referring to the standard formaldehyde working curve.

[0012] Further, the reaction solution added to the container containing the test sample is an acetylacetone solution. Its preparation method is to weigh 75 g of ammonium acetate, dissolve it in water, then add 1.5 mL of glacial acetic acid and 1 mL of acetylacetone, and make up the volume to 1000 mL with water in a volumetric flask. After preparation, let it stand for 12 h before use.

[0013] Further, the control protective solution added to the container containing the blank comparison sample is an ammonium acetate buffer solution. Its preparation method is to weigh 75 g of ammonium acetate, dissolve it in water, then add 1.5 mL of glacial acetic acid, and make up the volume to 1000 mL with water in a volumetric flask.

[0014] Further, the specific steps of Step 5 are as follows: Transfer the sample solution after filtration to a 10 mm absorption cell in the spectrophotometer, measure the absorbance of the sample solution at a wavelength of 412 nm, and calculate the content of free formaldehyde in the sample by referring to the standard formaldehyde working curve.

[0015] Adopting the above scheme, compared with the existing test methods, the formaldehyde rapid screening method provided by the present invention samples and tests a small number of samples with strong representativeness, which is convenient for quickly precipitating formaldehyde from the samples. At the same time, by adding a reaction solvent before heating, the precipitation efficiency of formaldehyde can be improved during the heating process, and the reaction efficiency between formaldehyde and the reaction solvent can be catalytically improved, thereby effectively improving the determination efficiency of formaldehyde content. The detection process that takes 120 - 150 min in the prior art can be compressed to be completed within 10 min as a whole, greatly improving the detection efficiency. Description of the Drawings

[0016] Figure 1 It is a comparison block diagram of the test process steps of the present invention and the prior art. Detailed Embodiments

[0017] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Please refer to Figure 1 , the present invention provides a rapid screening method for the determination of formaldehyde in textiles, comprising the following steps:

[0019] Step 1: Take two specimens from the same sample, cut them into pieces, and weigh 0.1 g of each specimen and put them into containers respectively.

[0020] Step 2: Add 10 ml of reaction solution to the container containing the test sample, and carry out the reaction in a water bath at 70±2°C for 5 minutes. The reaction solution added to the container containing the test sample is an acetylacetone solution, and its preparation method is to weigh 75 g of ammonium acetate, dissolve it in water, then add 1.5 mL of glacial acetic acid and 1 mL of acetylacetone, and make up the volume to 1000 mL with water in a volumetric flask. After preparation, it is left standing for 12 h before use. At the same time, add a control protection solution to the container containing the blank comparison sample, and carry out the reaction in the same environment. The control protection solution added to the container containing the blank comparison sample is an ammonium acetate buffer solution, and its preparation method is to weigh 75 g of ammonium acetate, dissolve it in water, then add 1.5 mL of glacial acetic acid, and make up the volume to 1000 mL with water in a volumetric flask.

[0021] Step 3: After the reaction is completed, quickly cool the sample solution to room temperature.

[0022] Step 4: Filter the cooled sample solution to filter out the undissolved fabric fragments in the sample solution, so as to ensure that when using a spectrophotometer to detect the sample solution, the test results will not be affected by the fabric being mixed in the solution.

[0023] Step 5: Take equal amounts of the sample solution from the filtrate into a spectrophotometer, measure the absorbance of formaldehyde in the sample solution, and calculate the content of free formaldehyde in the sample by referring to the standard formaldehyde working curve. The specific steps are as follows: Transfer the filtered sample solution to a 10 mm absorption cell in the spectrophotometer, measure the absorbance of the sample solution at a wavelength of 412 nm, and calculate the content of free formaldehyde in the sample by referring to the standard formaldehyde working curve.

[0024] In some embodiments, the specific test process is as follows:

[0025] Take two samples from the sample, cut them into pieces, and weigh 0.1 g of each sample accurately to 10 mg, and place them into 20-ml stoppered test tubes respectively. The samples can be selected from the positions on the fabric or cloth that require formaldehyde for processing, so as to calculate the maximum proportion of formaldehyde content in the sample by calculating the proportion of such representative sites in the tested sample. Divide the two groups of samples into test samples and blank control samples. Add 10 ml of acetylacetone solution to the test tube containing the test sample, and add 10 ml of ammonium acetate buffer solution to the test tube containing the blank control sample. After sealing the two groups of test tubes with rubber stoppers or glass stoppers, place the test tubes in a water bath at 70 °C for reaction for 5 min. By taking a small amount of the sample and heating it in a water bath under high temperature conditions, the release of formaldehyde from the sample can be accelerated, and the reaction efficiency between formaldehyde and acetylacetone solution can be catalyzed by increasing the temperature. Therefore, the color development of formaldehyde can be completed within 5 min. Then, quickly cool the solution in the test tube by water cooling or air cooling, and then filter the colored sample solution in the test tube. Then, absorb the sample solution from the filtrate into a 10-mm absorption cell of a spectrophotometer and measure the absorbance at a wavelength of 412 nm. Refer to the formaldehyde working curve to calculate the content of free formaldehyde in the sample.

[0026] The specific calculation process is as follows:

[0027] Calculate the corrected absorbance of each specimen according to Equation (1):

[0028] A = A 1 - A 2 ……(1)

[0029] In the formula:

[0030] A —— Corrected absorbance;

[0031] A 1 —— Absorbance of the colored sample solution;

[0032] A 2 —— Absorbance of the blank sample solution;

[0033] Use the corrected absorbance value to find out the formaldehyde concentration through the formaldehyde working curve.

[0034] Calculate the formaldehyde content in the specimen according to Equation (2):

[0035]

[0036] In the formula:

[0037] X —— Formaldehyde content in the specimen, unit: milligram per kilogram (mg / kg);

[0038] c——The formaldehyde concentration in the sample solution, unit: milligram per liter (mg / L);

[0039] V——The volume of the sample solution, unit: milliliter (mL);

[0040] In this example, the formaldehyde curve is y = 7.923x - 0.016, where A 1 = 0.128; A 2 = 0.008;

[0041] m = 0.100 g; V = 10 ml; then the formaldehyde concentration X is 93 mg / kg.

[0042] Compared with the existing testing methods, the formaldehyde rapid screening method provided by the present invention involves sampling and testing a small number of highly representative samples, facilitating the precipitation of formaldehyde from the samples as soon as possible. Meanwhile, by adding a reaction solvent before heating, during the heating process, the precipitation efficiency of formaldehyde can be improved, and the reaction efficiency between formaldehyde and the reaction solvent can be catalytically enhanced, thereby effectively improving the determination efficiency of formaldehyde content. The detection process that originally took 120 - 150 minutes in the prior art can be compressed to within 10 minutes to complete the overall detection, greatly improving the detection efficiency.

[0043] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A rapid screening method for determining formaldehyde in textiles, characterized in that: The steps include: Step 1: Take two pieces of the same sample, cut them into pieces, weigh 0.1g of each sample and put them into containers respectively; Step 2: Add 10 ml of reaction solution to the container containing the test sample, and react in a water bath at 70±2°C for 5 minutes; at the same time, add the control protection solution to the container containing the blank control sample and react under the same environment; wherein: The reaction liquid added to the container containing the test sample is an acetylacetone solution, which is prepared by weighing 75g of ammonium acetate and dissolving it in water, then adding 1.5mL of glacial acetic acid and 1mL of acetylacetone, and diluting the volume into a 1000mL volumetric flask with water. After the preparation is completed, let it stand for 12 hours before use; The control protection solution added to the container containing the blank control sample is an ammonium acetate buffer solution, which is prepared by weighing 75g of ammonium acetate and dissolving it in water, then adding 1.5mL of glacial acetic acid, and diluting the volume to a 1000mL volumetric flask with water; Step 3: After the reaction is completed, the sample solution is quickly cooled to room temperature; Step 4: Filter the cooled sample solution; Step 5: Take an appropriate amount of sample liquid from the filtrate and put it into the spectrophotometer, measure the absorbance of formaldehyde in the sample liquid, and calculate the content of free formaldehyde in the sample by comparing it with the standard formaldehyde working curve.

2. The rapid screening method for determining formaldehyde in textiles according to claim 1, characterized in that: The specific steps of step 5 are: pipetting the filtered sample solution into a 10 mm absorption cell in a spectrophotometer, measuring the absorbance of the sample solution at a wavelength of 412 nm, and calculating the content of free formaldehyde in the sample by comparing with the standard formaldehyde working curve.

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