Determination of four amide substances in textiles

Abstract

The invention discloses a method for determining 4 kinds of amide substances in a textile, including the following steps: step one, extracting formamide, N, N-dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone from the textile; step two, eluting and determining with a liquid chromatograph; step three, preparing a standard solution; step four, qualitative analysis of 4 kinds of amide substances; step five, calculating the content of N, N-dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone in the sample. The method is easy to operate, can simultaneously and efficiently detect 4 kinds of amide substances in textiles, and the data are reliable and effective.

Description

Technical Field

[0001] The invention relates to a method for determining four amide substances in textiles. Background Art

[0002] Formamide is an intermediate used as a raw material for the production of dyes, fragrances, pigments, adhesives, textile auxiliaries, paper treatment agents and other chemical products. It can be used as a solvent for synthetic fiber spinning, plastic processing, wood casein ink production, etc. N,N-dimethylformamide is not only an important intermediate in organic synthesis, but also widely used as a solvent for reactions. It is a good solvent for a variety of polymers such as polyethylene, polyvinyl chloride, polyacrylonitrile, polyamide, etc. It can be used for wet spinning of synthetic fibers such as polyacrylonitrile fibers, synthesis of polyurethanes and plastic film making. N,N-dimethylacetamide is mainly used as a solvent for synthetic fibers (acrylonitrile) and polyurethane spinning and synthetic polyamide resins, and is widely used in polymer films, coatings and medicines. N-methylpyrrolidone is widely used in high-grade lubricating oil refining, polymer synthesis, insulating materials, pesticides, pigments and cleaning agents. The above four organic solvents are mainly absorbed into the human body through skin contact and respiratory tract. The effects on the human body include skin and mucous membrane irritation. Acute poisoning will cause nausea, vomiting, constipation, and respiratory irritation symptoms such as throat congestion and cough. Chronic poisoning manifests as changes in the nervous system, vascular tone, and synthesis and detoxification functions of the liver. Studies have shown that N-methylpyrrolidone can also cause birth defects and other reproductive toxicity. Therefore, it is necessary to detect these four organic solvents. Oeko-TexStandard100 sets limit requirements for the above four organic solvents. The content of the four organic solvents in textiles made of ordinary materials should be <0.05%, and the content of the four organic solvents in textiles made of acrylic, spandex, polyurethane and coated textiles should be <0.10%. In my country's Technical Requirements for Ecological Textiles GB / T18885-2020, the limit requirements for N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone are 0.05%, and the limit requirement for formamide is 0.02%. However, there is currently no standard method that can simultaneously determine the above four amide substances in textiles, which affects the detection efficiency. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a method for determining four amide substances in textiles, which is easy to operate, can simultaneously and efficiently detect the four amide substances in textiles, and the data are reliable and effective.

[0004] To achieve the above object, the present invention provides a method for determining four amide substances in textiles, comprising the following steps:

[0005] Step 1: weigh 2.00 g of shredded textiles, place them in a 100 mL stoppered conical flask, add 20 mL of ultrapure water, immerse all the samples in ultrapure water, extract them in an ultrasonic generator, and then adjust the pH of the extract to 6.8 with HCl and NaOH;

[0006] Step 2: Activate PGC with 5 mL of methanol and 5 mL of ultrapure water, 500 mg / 6 ml of graphitized carbon solid phase extraction column, and then add the extract in step 1 to the graphitized carbon solid phase extraction column 4 times, control the loading speed ≤ 2 mL / min, and then rinse with methanol-water with a volume ratio of 1:7 at the same speed, drain the extraction column, and then elute with 3 ml of methanol at a speed of 2.5 mL / min. The eluate is dehydrated through a small column pre-loaded with 3 g of anhydrous Na2SO4, and then the small column is rinsed with 1.5 ml of methanol. The collected eluate is diluted to 5 ml with acetonitrile or methanol, filtered through an organic filter membrane, and used for liquid chromatography determination;

[0007] Step 3: Use acetonitrile or methanol to prepare standard stock solutions of about 1000 μg / ml for formamide, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone; take appropriate amount of the above four standard stock solutions in a volumetric flask, dilute them step by step with methanol to prepare mixed standard working solutions with concentrations of 0.5 μg / ml, 1 μg / ml, 3 μg / ml, 5 μg / ml and 10 μg / ml, respectively, and use high performance liquid chromatography to determine the concentrations of formamide, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone in the sample solution and the standard working solution;

[0008] Step 4, comparing the spectra and retention times of the analyte in the sample with formamide, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone. If the spectra and retention times of the two are the same, it can be determined that the sample to be tested contains formamide, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone;

[0009] Step 5: The linear regression equation of formamide is obtained from the standard curve of formamide: y=30.01x-0.512, wherein y is the response intensity of the UV-visible spectrometer and x is the concentration of formamide in μg / mL; the linear regression equation of N,N-dimethylformamide is obtained from the standard curve of N,N-dimethylformamide: y=55.43x-4.317, wherein x is the concentration of N,N-dimethylformamide in μg / mL; the linear regression equation of N,N-dimethylacetamide is obtained from the standard curve of N,N-dimethylacetamide. Process: y=58.58x-3.049, x is the concentration of N,N-dimethylacetamide, unit is μg / mL; the linear regression equation of N-methylpyrrolidone is obtained from the standard curve: y=47.29x+1.896, x is the concentration of N-methylpyrrolidone, unit is μg / mL; the response intensity of the four amide substances in the sample is determined, substituted into the linear regression equation of the corresponding standard curve, and then combined with the sample mass, the content of the corresponding amide substance in the measured sample is calculated.

[0010] As a further configuration of the present invention, the test conditions of the high performance liquid chromatography in step 3 are

[0011] a) Chromatographic column: AthenaC18-WP, 5μm, 4.6mm×250mm

[0012] b) Flow rate: 1 mL / min;

[0013] c) Column temperature: 35°C;

[0014] d) Injection volume: 10 μL;

[0015] e) Detector: DAD diode array detector

[0016] f) Detection wavelength: 195nm;

[0017] g) Mobile phase: A is 12.5 mmol / L potassium dihydrogen phosphate aqueous solution, B is acetonitrile, A:B=9:1.

[0018] As a further configuration of the present invention, the ultrasonic extraction time of the ultrasonic generator in step 1 is 30 minutes.

[0019] The beneficial effect of such a setting is that, by adopting the above scheme, additional testing can be carried out efficiently and quickly, and the test is accurate and the calculation is convenient. The specific content can be quickly determined through the linear relationship, and the detection of four amide substances in textiles can be effectively solved with high detection efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flowchart of the present invention;

[0021] Figure 2is a high performance liquid chromatogram of four amide substances of the present invention;

[0022] Figure 3 is a standard curve diagram of formamide of the present invention;

[0023] Figure 4 is a standard curve diagram of N,N-dimethylformamide of the present invention;

[0024] Figure 5 is a standard curve diagram of N,N-dimethylacetamide of the present invention;

[0025] Figure 6 It is the standard curve diagram of N-methylpyrrolidone of the present invention. DETAILED DESCRIPTION

[0026] The embodiment of the method for determining four amide substances in a textile of the present invention is as follows: Figures 1 to 6 As shown: including the following steps,

[0027] The following steps are included:

[0028] Step 1: weigh 2.00 g of shredded textiles, place them in a 100 mL stoppered conical flask, add 20 mL of ultrapure water, immerse all the samples in ultrapure water, extract them in an ultrasonic generator, and then adjust the pH of the extract to 6.8 with HCl and NaOH;

[0029] Step 2: Activate PGC with 5 mL of methanol and 5 mL of ultrapure water, 500 mg / 6 ml of graphitized carbon solid phase extraction column, and then add the extract in step 1 to the graphitized carbon solid phase extraction column 4 times, control the loading speed ≤ 2 mL / min, and then rinse with methanol-water with a volume ratio of 1:7 at the same speed, drain the extraction column, and then elute with 3 ml of methanol at a speed of 2.5 mL / min. The eluate is dehydrated through a small column pre-loaded with 3 g of anhydrous Na2SO4, and then the small column is rinsed with 1.5 ml of methanol. The collected eluate is diluted to 5 ml with acetonitrile or methanol, filtered through an organic filter membrane, and used for liquid chromatography determination;

[0030] Step 3: Use acetonitrile or methanol to prepare standard stock solutions of about 1000 μg / ml for formamide, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone; take appropriate amount of the above four standard stock solutions in a volumetric flask, dilute them step by step with methanol to prepare mixed standard working solutions with concentrations of 0.5 μg / ml, 1 μg / ml, 3 μg / ml, 5 μg / ml and 10 μg / ml, respectively, and use high performance liquid chromatography to determine the concentrations of formamide, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone in the sample solution and the standard working solution;

[0031] Step 4, comparing the spectra and retention times of the analyte in the sample with formamide, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone. If the spectra and retention times of the two are the same, it can be determined that the sample to be tested contains formamide, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone;

[0032] Step 5: The linear regression equation of formamide is obtained from the standard curve of formamide: y=30.01x-0.512, wherein y is the response intensity of the UV-visible spectrometer and x is the concentration of formamide in μg / mL; the linear regression equation of N,N-dimethylformamide is obtained from the standard curve of N,N-dimethylformamide: y=55.43x-4.317, wherein x is the concentration of N,N-dimethylformamide in μg / mL; the linear regression equation of N,N-dimethylacetamide is obtained from the standard curve of N,N-dimethylacetamide. Process: y=58.58x-3.049, x is the concentration of N,N-dimethylacetamide, unit is μg / mL; the linear regression equation of N-methylpyrrolidone is obtained from the standard curve: y=47.29x+1.896, x is the concentration of N-methylpyrrolidone, unit is μg / mL; the response intensity of the four amide substances in the sample is determined, substituted into the linear regression equation of the corresponding standard curve, and then combined with the sample mass, the content of the corresponding amide substance in the measured sample is calculated.

[0033] As a further setting of this method, the test conditions of the high performance liquid chromatography in step 3 are

[0034] a) Chromatographic column: AthenaC18-WP, 5μm, 4.6mm×250mm

[0035] b) Flow rate: 1 mL / min;

[0036] c) Column temperature: 35°C;

[0037] d) Injection volume: 10 μL;

[0038] e) Detector: DAD diode array detector

[0039] f) Detection wavelength: 195nm;

[0040] g) Mobile phase: A is 12.5 mmol / L potassium dihydrogen phosphate aqueous solution, B is acetonitrile, A:B=9:1.

[0041] As a further configuration of the method, the ultrasonic extraction time of the ultrasonic generator in step 1 is 30 minutes.

[0042] The above example is only one preferred specific example of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention are all included in the protection scope of the present invention.

Claims

1. A method for determining four amide substances in textiles, characterized in that: The following steps are included: Step 1: Weigh 2.00 g of shredded textiles and place them in a 100 mL stoppered conical flask. Add 20 mL of ultrapure water so that all samples are immersed in ultrapure water. Extract in an ultrasonic generator and then adjust the pH of the extract to 6.8 with HCl and NaOH. Step 2: Activate PGC with 5 mL of methanol and 5 mL of ultrapure water, 500 mg / 6 ml of graphitized carbon solid phase extraction column, and then add the extract in step 1 to the graphitized carbon solid phase extraction column 4 times, control the loading speed ≤ 2 mL / min, and then rinse with methanol-water with a volume ratio of 1:7 at the same speed, drain the extraction column, and then elute with 3 ml of methanol at a speed of 2.5 mL / min. The eluate is dehydrated through a small column pre-loaded with 3 g of anhydrous Na2SO4, and then the small column is rinsed with 1.5 ml of methanol. The collected eluate is diluted to 5 ml with acetonitrile or methanol, filtered through an organic filter membrane, and used for liquid chromatography determination; Step 3: Use acetonitrile or methanol to prepare standard stock solutions of 1000 μg / ml for formamide, N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone respectively; take appropriate amount of the above four standard stock solutions in a volumetric flask, dilute them step by step with methanol to prepare mixed standard working solutions with concentrations of 0.5 μg / ml, 1 μg / ml, 3 μg / ml, 5 μg / ml and 10 μg / ml respectively, and use high performance liquid chromatography to determine the concentrations of formamide, N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone in the sample solution and the standard working solution respectively; Step 4, comparing the spectra and retention times of the analyte in the sample with formamide, N, N-dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone. If the spectra and retention times of the two are the same, it can be determined that the sample contains formamide, N, N-dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone; Step 5, the linear regression equation of formamide is obtained from the standard curve: y = 30.01x - 0.512, wherein y is the response intensity of the UV-visible spectrometer detector, and x is the concentration of formamide in μg / mL; the linear regression equation of N, N-dimethylformamide is obtained from the standard curve: y = 55.43x - 4.317, wherein x is the concentration of N, N-dimethylformamide in μg / mL; the linear regression equation of N, N-dimethylacetamide is obtained from the standard curve: y = 58.58x - 3.049, wherein x is the concentration of N, N-dimethylacetamide in μg / mL; the linear regression equation of N-methylpyrrolidone is obtained from the standard curve: y = 47.29x + 1.896 , x is the concentration of N-methylpyrrolidone, the unit is μg / mL; the response intensity of the four amide substances in the sample is measured, substituted into the linear regression equation of the corresponding standard curve, and then combined with the sample mass to calculate the content of the corresponding amide substances in the measured sample.

2. The method for determining four amide substances in textiles according to claim 1, characterized in that: Test conditions of high performance liquid chromatography in step 3 a) Chromatographic column: Athena C18-WP, 5 μm, 4.6 mm × 250 mm b) Flow rate: 1 mL / min; c) Column temperature: 35 °C; d) Injection volume: 10 µL; e) Detector: DAD diode array detector f) Detection wavelength: 195nm; g) Mobile phase: A is 12.5 mmol / L potassium dihydrogen phosphate aqueous solution, B is acetonitrile, A:B=9:

1.

3. The method for determining four amide substances in textiles according to claim 2, characterized in that: The ultrasonic extraction time of the ultrasonic generator in the step 1 is 30 min.

Images