Method for detecting purity of phosphorus-containing flame retardant

Abstract

The invention discloses a method for detecting the purity of a phosphorus-containing flame retardant, and belongs to the technical field of flame retardant detection. The specific test method comprises the test steps of selecting a solvent, preparing a to-be-tested solution, determining the maximum absorption wavelength, determining absorbance, calculating the purity of a sample and the like, and analyzing and processing an experimental result. The solvent is filtered through a 600-mesh screen, the influence of impurities in the solvent on an experimental result is eliminated, and the scientificity of the experimental result is ensured by parallelly determining the average value recorded for three times; the testing method has the advantages of low cost, simplicity and convenience in operation, short detection period and the like, and can realize rapid detection of a plurality of samples based on multiple stations of an ultraviolet-spectrophotometer, so that the working efficiency is improved; meanwhile, the method for detecting the purity of the phosphorus-containing flame retardant provided by the invention can be used for comparing the quality of products from different manufacturers and the batch stability of the products at the same time, and is beneficial for enterprises to control the quality of the products.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of flame retardant detection, and particularly relates to a detection method for the purity of phosphorus-containing flame retardants. BACKGROUND

[0002] Phosphorus-containing flame retardants are widely concerned in the flame retardant field due to their low-halogen or halogen-free characteristics. At present, as a kind of efficient, low-toxic and environmentally friendly flame retardant, phosphorus-containing flame retardants are widely used in the flame-retardant industry of electronic products. The phosphorus-containing flame retardant belongs to an organic compound, which is often synthesized by multi-process organic reaction and then separated and purified. In industrial applications, the purity is a key performance index of the product. The liquid chromatography or gas chromatography is commonly used to determine the purity of organic compounds. However, the phosphorus-containing flame retardant is a high-melting-point solid substance, and cannot be detected by gas chromatography. The liquid chromatograph is relatively expensive, has high purchase cost and occupies a large space. SUMMARY

[0003] In order to overcome the above problems, the application provides a detection method for the purity of phosphorus-containing flame retardants.

[0004] The technical scheme adopted by the application is as follows:

[0005] A detection method for the purity of phosphorus-containing flame retardants, comprising the following steps:

[0006] Step 1: sample preparation: take 20㎎-100mg clean and impurity-free flame retardant sample, place it in a beaker, add a solvent filtered by a 600-mesh screen, dissolve and transfer to a volumetric flask, fully dissolve the flame retardant sample in the solvent, perform constant volume after complete dissolution, shake uniformly, use a pipette to take 30mL solution into a 100mL volumetric flask, perform constant volume and shake to mix uniformly;

[0007] Step 2: spectral determination: use a pipette gun to take 5mL solution and place it in a cuvette, determine the absorption curve under 190nm-800nm, and record the maximum absorption wavelength;

[0008] Step 3: photometric determination: after selecting the maximum absorption wavelength, determine the absorbance at the wavelength, determine three times for each sample, record the average value of the test results, and compare with the standard to determine the purity of the sample;

[0009] or after selecting the maximum absorption wavelength, determine the absorbance at the wavelength, determine three times for each sample, record the average value of the test results, compare the photometric values of different batches of samples, and determine the batch stability.

[0010] The phosphorus-containing flame retardant is a mixture of one or more of hydroquinone bis(diphenyl phosphate), resorcinol bis(diphenyl phosphate) triphenyl phosphate, resorcinol bis[di(2,6-dimethylphenyl) phosphate], hexaphenoxy cyclotriphosphazene, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), and 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-HQ).

[0011] The solvent is a combination of one or more of butanone, ethylene glycol monomethyl ether, acetone, 2-heptanone, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, methanol, and ethanol.

[0012] The cuvette is a quartz cuvette, and the optical path is not limited, and the test conditions are ensured to be consistent.

[0013] The purity of the sample to be measured is determined according to the value of the absorbance of the standard sample, and the calculation formula is as follows:

[0014] w=A1 / A RM * 100 %.

[0015] In the formula, w is the purity of the sample, A1 is the absorbance of the sample under the same test conditions, A RM is the absorbance of the standard sample under the same test conditions, and 100 % is the purity of the standard sample.

[0016] The advantages of the present application are as follows:

[0017] A low-cost, simple-to-operate, efficient, and reliable phosphorus-containing flame retardant purity detection method is provided, the ultraviolet-visible spectrophotometer instrument used for detection has low cost, high efficiency, good reproducibility, and small sample amount, and the product quality control cost of an enterprise is reduced.

[0018] The provided phosphorus-containing flame retardant purity detection method can simultaneously detect multiple workstations when detecting a single sample, facilitating comparison of product batch stability. At the same time, comparison and analysis of incoming materials from different manufacturers can also be achieved. DETAILED DESCRIPTION

[0019] Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor belong to the scope of protection of the present application.

[0020] Embodiment 1

[0021] A detection method for the purity of a phosphorus-containing flame retardant, comprising the following steps:

[0022] Step one: take 20 mg of clean and impurity-free flame retardant sample, accurate to 0.1 mg, put it in a beaker, add analytical pure butanone filtered with a 600 mesh screen, after dissolving, transfer to a 250 mL volumetric flask (a few times), after the sample is completely dissolved, carry out constant volume, shake uniformly, then use a pipette to take 30 mL of solution into a 100 mL volumetric flask, constant volume and shake to mix uniformly;

[0023] Step two: use a pipette to take 5 mL of the test solution into a 1 cm light path quartz cuvette, deduct the background absorption of the reference solution, measure the absorbance at 220 nm, measure three times in parallel, and record the average value A1;

[0024] Step three: according to the above determination steps, measure the absorbance A of the standard sample under the same conditions RM The purity of the standard substance is 100%, so the purity determination result w of the flame retardant sample 1 is:

[0025] w = A1 / A RM × 100%.

[0026] Example 2

[0027] A method for detecting the purity of a phosphorus-containing flame retardant, comprising the following steps:

[0028] Step one: take 50 mg of clean and impurity-free flame retardant sample, accurate to 0.1 mg, put it in a beaker, add analytical pure acetonitrile filtered with a 600 mesh screen, after dissolving, transfer to a 250 mL volumetric flask (a few times), after the sample is completely dissolved, carry out constant volume, shake uniformly, then use a pipette to take 10 mL of solution into a 100 mL volumetric flask, constant volume and shake to mix uniformly;

[0029] Step two: use a pipette to take 5 mL of the test solution into a 1 cm light path quartz cuvette, deduct the background absorption of the reference solution, measure the absorbance at 254 nm, measure three times in parallel, and record the average value A1;

[0030] Step three: according to the above determination steps, measure the absorbance A of the standard sample under the same conditions RM The purity of the standard substance is 100%, so the purity determination result w of the flame retardant sample is:

[0031] w = A1 / A RM × 100%.

[0032] Example 3

[0033] Compare the quality of products from different manufacturers:

[0034] A method for detecting the purity of a phosphorus-containing flame retardant, comprising the following steps:

[0035] Step one: take 50 mg clean and impurity-free flame retardant sample, accurate to 0.1 mg, placed in a beaker, add analytical pure acetonitrile filtered with 600 mesh screen, after dissolution, transfer to a 250 mL volumetric flask (a few times), after the sample is completely dissolved, make up to volume, shake uniformly, use a pipette to take 10 mL solution to a 100 mL volumetric flask, make up to volume and shake to mix uniformly;

[0036] Step two: use a pipette to take 5 mL of the solution to be measured in a 1 cm light path quartz cuvette, deduct the reference solution background absorption, measure the absorbance at 254 nm, measure three times in parallel, record the average value A1;

[0037] Step three: the samples of different manufacturers are prepared according to the above steps, and the absorbance is measured, and the measurement results are recorded as A2, A3, A4, etc.

[0038] According to the above determination steps, the absorbance A of the standard sample under the same conditions is measured RM , the measurement result is close to (A x / A RM above 90%) is determined to be qualified.

[0039] Sample Name A RM ]]> [A1] [A2] [A3] [A4] Absorbance 0.204 0.191 0.196 0.173 0.174 Ratio / % / 93.63 96.08 84.80 85.29 Result Determination / Pass Pass Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail Fail

[0040] The embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method for detecting the purity of a phosphorus-containing flame retardant, characterized by: Comprising the following steps: Step one: sample preparation: take 20㎎-100mg clean and impurity-free flame retardant sample, place in beaker, add solvent filtered with 600 mesh screen, dissolve and transfer to volumetric flask, dissolve the flame retardant sample in the solvent, dissolve the sample completely, perform constant volume, shake uniformly, use pipette to take 30mL solution to 100mL volumetric flask, constant volume and shake to mix uniformly; Step two: spectral determination: use a pipette to take 5mL solution and place it in a cuvette, measure the absorption curve at 190nm-800nm, and record the maximum absorption wavelength; Step three: photometric determination: after selecting the maximum absorption wavelength, measure the absorbance at this wavelength, measure three times for each sample, record the average value of the test results, and compare with the standard to determine the sample purity; Or after selecting the maximum absorption wavelength, measure the absorbance at this wavelength, measure three times for each sample, record the average value of the test results, compare the photometric values of different batches of samples to determine the batch stability.

2. The method for detecting the purity of phosphorus-containing flame retardant according to claim 1, characterized in that: The phosphorus-containing flame retardant is a mixture of one or more of hydroquinone bis(diphenyl phosphate), resorcinol bis(diphenyl phosphate), triphenyl phosphate, resorcinol bis[di(2,6-dimethylphenyl) phosphate], hexaphenoxy cyclotriphosphazene, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide.

3. The method for detecting the purity of phosphorus-containing flame retardant according to claim 1, characterized in that: The solvent is a combination of one or more of butanone, ethylene glycol monomethyl ether, acetone, 2-heptanone, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, methanol, and ethanol.

4. The method for detecting the purity of a phosphorus-containing flame retardant according to claim 1, characterized in that: The cuvette is a quartz cuvette, and the optical path is not limited to ensure consistent test conditions.

5. The method for detecting the purity of a phosphorus-containing flame retardant according to claim 1, characterized in that: The purity of the sample to be tested is determined according to the absorbance value of the standard, and the calculation formula is as follows: w = A1 / A RM x 100%; where: w = sample purity; A1= absorbance of sample under identical test conditions; A RM A0= absorbance of standard under identical test conditions; 100% = standard purity.