Method for determining trimethyl phosphate in textile

Abstract

The invention provides a method for determining trimethyl phosphate in textiles, which comprises the following steps: dissolving trimethyl phosphate in a volumetric flask by using diethyl ether, and fixing the volume to obtain a standard stock solution; fixing the volume of the standard stock solution by using diethyl ether to form a standard solution, determining a response value by using a gas chromatograph-mass spectrometer, and suggesting a standard curve associated with the concentration and the response value; soaking a textile sample in the standard stock solution, periodically stirring the solution to enable trimethyl phosphate to be uniformly attached to the textile sample, and drying the textile sample when the standard stock solution is volatilized to be nearly dry to obtain a textile positive sample; cutting the positive sample of the textile into fragments, putting the fragments into an extraction reactor, adding an extraction solvent for extraction, cooling to room temperature, filtering by a filter membrane, analyzing by using a gas chromatograph-mass spectrometer, and determining the content of trimethyl phosphate in the textile according to the standard curve. The invention establishes an analysis method for determining trimethyl phosphate in textiles by using a gas chromatograph-mass spectrometer.

Description

Technical Field

[0001] The present disclosure belongs to the technical field of trimethyl phosphate determination, and particularly relates to a method for determining trimethyl phosphate in textiles. Background Art

[0002] Trimethyl phosphate is mainly used as a solvent, extractant and polyester heat stabilizer for pesticides. Short-term exposure has an effect on the central nervous system, and long-term exposure leads to weakness and paralysis, causing genetic damage to humans. Cotton is one of the main raw materials for textile products in China. Pesticides are inevitably used in the cotton planting process to prevent insect damage to crops. In addition, silk is also one of the raw materials for high-grade clothing. It has been found that dichlorvos will be rapidly decomposed into trimethyl phosphate in tussah silkworms. It has also been found that during the production process of polyester (PET), trimethyl phosphate is added as a heat stabilizer to inhibit the degradation during the melt molding process of PET. In summary, trimethyl phosphate may appear in textile products such as cotton, silk, and polyester fibers in the form of residues.

[0003] Therefore, in the face of the potential hazards that trimethyl phosphate may pose to textile products in the future, it is necessary to measure trimethyl phosphate in textiles, which is of great significance for ensuring the quality of consumer goods and protecting the safety of consumers. Currently, there is no detection method for this substance in the field of textile clothing. Summary of the Invention

[0004] The present disclosure aims to at least solve one of the technical problems existing in the prior art, and provides a method for determining trimethyl phosphate in textiles.

[0005] The present disclosure provides a method for determining trimethyl phosphate in textiles, and the determination method includes:

[0007] Dissolve trimethyl phosphate in ether in a volumetric flask and make up the volume to obtain a standard stock solution;

[0008] Make up the volume of the standard stock solution with ether to form standard solutions with different concentrations, measure the response values using a gas chromatography-mass spectrometry (GC-MS) instrument, and establish a standard curve correlating the concentration and the response value;

[0009] Immerse the textile sample in the standard stock solution, stir the solution periodically to make trimethyl phosphate evenly adhere to the textile sample. When the standard stock solution is nearly evaporated to dryness, dry the textile sample to obtain a positive textile sample;

[0010] Cut the positive textile sample into pieces and place them in an extraction reactor, add an extraction solvent for extraction. After cooling to room temperature, filter through a filter membrane and then analyze using a GC-MS instrument, and determine the content of trimethyl phosphate in the positive textile sample according to the standard curve.

[0011] Optionally, in the standard stock solution, the mass concentration of trimethyl phosphate is 1000 μg / mL.

[0012] Optionally, the concentration range of the standard solution is 10 - 50 μg / mL.

[0013] Optionally, the textile sample is immersed in the standard stock solution, and the stirring period of the solution is 20 min / time.

[0014] Optionally, the drying temperature of the textile sample is 80 °C and the time is 1 h.

[0015] Optionally, the solid-liquid ratio of the textile positive sample placed in the extraction reactor to the extraction solvent is 1:(10 - 30) g / mL.

[0016] Optionally, the extraction temperature is 35 - 45 °C and the extraction time is 55 - 70 min.

[0017] Optionally, the pore size of the filter membrane is 0.4 - 0.5 μm.

[0018] Optionally, the extraction solvent is methanol or acetone; and / or,

[0019] The extraction method is ultrasonic extraction.

[0020] Optionally, the parameters of the gas chromatography-mass spectrometry are as follows:

[0021] The chromatographic column specification is 30 m × 0.25 mm × 0.25 μm;

[0022] The inlet temperature is 250 °C;

[0023] The mass spectrometry interface temperature is 280 °C;

[0024] The ion source temperature is 290 °C;

[0025] The quadrupole temperature is 150 °C;

[0026] The temperature programming: hold at 60 °C for 1 min, increase the temperature to 100 °C at a rate of 10 °C / min, hold for 1 min, increase the temperature to 220 °C at a rate of 30 °C / min, hold for 1 min;

[0027] Ionization mode: EI source;

[0028] Injection mode: pulse splitless injection;

[0029] The pulse pressure is 45 psi.

[0030] The present disclosure provides a method for determining trimethyl phosphate in textiles. The determination method includes: dissolving trimethyl phosphate in ether in a volumetric flask and making up the volume to obtain a standard stock solution; making up the volume of the standard stock solution with ether to form standard solutions with different concentrations, measuring the response values using a gas chromatography-mass spectrometry (GC-MS) instrument, and establishing a standard curve correlating the concentration and the response value; soaking a textile sample in the standard stock solution, periodically stirring the solution to make trimethyl phosphate evenly adhere to the textile sample, drying the textile sample when the standard stock solution is nearly evaporated to dryness to obtain a positive textile sample; cutting the positive textile sample into pieces and placing them in an extraction reactor, adding an extraction solvent for extraction, cooling to room temperature, filtering through a filter membrane, and then analyzing using a GC-MS instrument, and determining the content of trimethyl phosphate in the positive textile sample according to the standard curve. The present disclosure establishes an analytical method for determining trimethyl phosphate in textiles using a GC-MS instrument, filling the gap in the inspection ability of this item in textile and clothing products in China, and having very important significance for ensuring the quality of consumer goods and protecting the safety of consumers. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a flowchart of the method for determining trimethyl phosphate in textiles according to the specific embodiment of the present disclosure;

[0032] Figure 2 shows the influence of the solid-liquid ratio of the positive textile sample to the extraction solvent on the extraction efficiency of trimethyl phosphate in the positive textile sample after normalization in Example 1 of the present disclosure;

[0033] Figure 3 shows the influence of the extraction temperature on the extraction value of trimethyl phosphate in the positive textile sample in Example 2 of the present disclosure;

[0034] Figure 4 shows the influence of the extraction time on the extraction value of trimethyl phosphate in the positive textile sample in Example 3 of the present disclosure;

[0035] Figure 5 shows the influence of the type of extraction solvent on the extraction efficiency of trimethyl phosphate in the positive textile sample after normalization in Example 4 of the present disclosure;

[0036] Figure 6 shows the influence of the inlet temperature on the peak area of trimethyl phosphate in Example 5 of the present disclosure. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] To enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, which are some embodiments of the present disclosure, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[0038] As Figure 1 shown, the present disclosure provides a method S100 for determining trimethyl phosphate in textiles, including the following specific steps S110 to S140:

[0039] S110. Dissolve trimethyl phosphate in ether in a volumetric flask and make up the volume to obtain a standard stock solution.

[0040] In some preferred embodiments, in the standard stock solution, the mass concentration of trimethyl phosphate is 1000 μg / mL.

[0041] S120. Dilute the standard stock solution with ether to form standard solutions with different concentrations, measure the response values using a gas chromatography-mass spectrometry (GC-MS) instrument, and establish a standard curve correlating the concentration and the response value.

[0042] In some preferred embodiments, the concentration range of the trimethyl phosphate standard solution is 10 - 50 μg / mL, for example, 10.0, 20.0, 30.0, 40.0, 50.0 μg / mL, etc.

[0043] S130. Immerse the textile sample in the standard stock solution, stir the solution periodically to make the trimethyl phosphate evenly adhere to the textile sample. When the standard stock solution is almost evaporated to dryness, place the textile sample in an oven to dry and obtain a positive textile sample.

[0044] It should be noted that the present embodiment does not specifically limit the textiles. For example, it can be cotton fabrics, silk fabrics, polyester fibers and other textiles.

[0045] In some preferred embodiments, the textile sample is immersed in the standard stock solution, and the periodicity of stirring the solution is 20 min / time.

[0046] In some other preferred embodiments, the drying temperature of the textile sample is 80 °C and the time is 1 h.

[0047] S140. Cut the positive textile sample into 5-mm pieces and place them in an extraction reactor, add an extraction solvent for extraction. After cooling to room temperature, filter through a filter membrane and analyze using a GC-MS instrument, and determine the content of trimethyl phosphate in the positive textile sample according to the standard curve.

[0048] In some preferred embodiments, the solid-liquid ratio of the textile positive sample placed in the extraction reactor to the extraction solvent is 1:(10 - 30) g / mL. For example, 1:20 can be preferably selected.

[0049] In some other preferred embodiments, the extraction temperature of the ultrasonic cleaner is 35 - 45 °C, and the extraction time is 55 - 70 min. For example, 40 °C and 60 min can be preferably selected.

[0050] In some other preferred embodiments, the pore size of the filter membrane is 0.4 - 0.5 μm. For example, 0.45 μm can be preferably selected.

[0051] In some other preferred embodiments, the extraction solvent is methanol or acetone. For example, methanol can be preferably selected.

[0052] In some other preferred embodiments, the extraction method can adopt ultrasonic oscillation. Of course, in other embodiments, water bath oscillation extraction or Soxhlet extraction can also be adopted.

[0053] In some other preferred embodiments, the parameters of the gas chromatography-mass spectrometry (GC-MS) are as follows:

[0054] Chromatographic column: DB-5MS (30 m × 0.25 mm × 0.25 μm); injection port temperature: 250 °C; mass spectrometry interface temperature: 280 °C; ion source temperature: 290 °C; quadrupole temperature: 150 °C; ionization mode: EI source; injection mode: pulsed splitless injection, pulsed pressure: 45 psi; temperature programming: hold at 60 °C for 1 min, increase the temperature to 100 °C at a rate of 10 °C / min, hold for 1 min, increase the temperature to 220 °C at a rate of 30 °C / min, hold for 1 min. Quantitative method: external standard method.

[0055] The present disclosure realizes the determination of trimethyl phosphate in textiles by gas chromatography-mass spectrometry, and determines the optimal pretreatment conditions and GC-MS analysis conditions. This method is simple and easy to operate. The detection limit of this method is 21.5 mg / kg, the recovery rate is 93.1% - 96.4%, and the relative standard deviation is 5.1% - 6.5%. It is applicable to the detection of trimethyl phosphate in textiles.

[0056] The following will further illustrate the method for determining trimethyl phosphate in textiles in combination with specific examples:

[0057] Example 1

[0058] This example provides a method for determining trimethyl phosphate in textiles, including the following steps:

[0059] S1. Preparation of the standard stock solution:

[0060] Weigh an appropriate amount of trimethyl phosphate, dissolve it in diethyl ether in a volumetric flask and make up to the mark, so that the mass concentration of trimethyl phosphate is 1000 μg / mL.

[0061] S2. Preparation of the standard curve:

[0062] Standard curve: Pipette an appropriate amount of the trimethyl phosphate standard stock solution and make up to the mark with diethyl ether to form a standard solution. The concentrations of the trimethyl phosphate standard curve are 10.0, 20.0, 30.0, 40.0, and 50.0 μg / mL respectively, and a standard curve corresponding to different concentrations and response values is formed.

[0063] As Figure 2 shown, the concentration of trimethyl phosphate and the peak area of the chromatographic peak are used as the abscissa and ordinate of the curve to draw the standard curve, and the results are shown in Table 1.

[0064] Table 1 Standard curve and detection limit for the determination of trimethyl phosphate in textiles by gas chromatography-mass spectrometry

[0065]

[0066] S3. Preparation of positive samples:

[0067] Select pure cotton fabrics to prepare positive samples. Immerse the pure cotton fabrics in the trimethyl phosphate standard stock solution (prepared with diethyl ether), and stir once every 20 minutes to make the trimethyl phosphate evenly adhere to the fabric samples. When the trimethyl phosphate standard solution in the container has almost evaporated to dryness, place the positive samples in an 80 °C oven and dry for 1 h.

[0068] S4. Set the analysis conditions of the gas chromatography-mass spectrometer:

[0069] Chromatographic column: DB-5MS (30 m × 0.25 mm × 0.25 μm); inlet temperature: 250 °C; mass spectrometry interface temperature: 280 °C; ion source temperature: 290 °C; quadrupole temperature: 150 °C; ionization mode: EI source; injection mode: pulsed splitless injection, pulsed pressure: 45 psi; temperature program: hold at 60 °C for 1 min, increase the temperature to 100 °C at a rate of 10 °C / min, hold for 1 min, increase the temperature to 220 °C at a rate of 30 °C / min, hold for 1 min. Quantitative method: external standard method.

[0070] S5. Sample treatment and determination

[0071] Cut the textile sample into 5 mm pieces. Weigh 1.0 g of the sample into an extraction reactor, add 10 mL, 20 mL, 30 mL, and 40 mL of methanol respectively, and extract in a 40 °C ultrasonic cleaner for 60 min. After the extract is cooled to room temperature, filter it through a 0.45 μm filter membrane and then analyze it using a gas chromatography-mass spectrometer (GC-MS).

[0072] As Figure 2 shown, when the solid-liquid ratio of the extracted fabric positive sample to the extraction solvent methanol increases, the normalized extraction efficiency of trimethyl phosphate gradually decreases. Among them, when the solid-liquid ratio of the extracted fabric positive sample to the extraction solvent methanol is 1:10, the normalized extraction efficiency of trimethyl phosphate is the highest. However, it was observed during the experiment that the textile sample absorbed the extraction solvent significantly and there was less remaining extraction liquid, which might cause some difficulties for repeated sampling. Therefore, the optimal solid-liquid ratio in this example can be preferably 1:20.

[0073] Example 2

[0074] A method for determining trimethyl phosphate in textiles given in this example is the same as that in Example 1, except that the extraction temperature for sample treatment and determination in step S5 is changed and set to 30°C, 40°C, 50°C, and 60°C respectively to investigate the influence of different extraction temperatures on the extraction value of trimethyl phosphate.

[0075] As Figure 3 shown, when the extraction temperature is between 35 - 45°C, its extraction value is above 62.5%. Especially when the extraction temperature is 40°C, the extraction value of trimethyl phosphate is the highest. As the temperature further increases, the extraction value decreases instead. Therefore, the optimal extraction temperature in this example can be preferably 40°C.

[0076] Example 3

[0077] A method for determining trimethyl phosphate in textiles given in this example is the same as that in Example 1, except that the extraction time for sample treatment and determination in step S5 is changed and set to 30 min, 60 min, 75 min, 90 min, and 120 min respectively to investigate the influence of different extraction times on the extraction value of trimethyl phosphate.

[0078] As Figure 4 shown, when the extraction time is between 55 - 70 min, its extraction value is above 62.5%. Especially when the extraction time is 60 min, the extraction value of trimethyl phosphate is the highest. As the time further increases, the extraction value decreases instead. Therefore, the optimal extraction time in this example can be preferably 60 min.

[0079] Example 4

[0080] A method for determining trimethyl phosphate in textiles given in this example is the same as that in Example 1, except that the extraction solvents for sample treatment and determination in step S5 are changed to methanol, acetonitrile, n-hexane, ethyl acetate, acetone, methyl tert-butyl ether, toluene, and diethyl ether respectively to investigate the influence of the types of extraction solvents on the extraction value of trimethyl phosphate.

[0081] As Figure 5As shown, when methanol and acetone are used as extraction solvents, the extraction values of trimethyl phosphate are relatively high. Secondly, the extraction value using ethyl acetate is also relatively high. However, it should be understood that considering that the boiling point of methanol is higher than that of acetone, a higher extraction temperature can be attempted. Therefore, methanol can be preferably used as the best extraction solvent in this example. Of course, other extraction solvents can also be preferred under other conditions.

[0082] Example 5

[0083] A method for determining trimethyl phosphate in textiles given in this example is the same as that in Example 1, except that the inlet temperature in step S4 is changed and set to 210°C, 230°C, 250°C, 270°C, and 290°C respectively to investigate the influence of the inlet temperature on the peak area of trimethyl phosphate.

[0084] As Figure 6 shown, the peak area of trimethyl phosphate shows an obvious increasing trend in the range of 210°C to 250°C, and shows a decreasing trend after reaching the highest point at 250°C. The peak area of trimethyl phosphate is the largest when the inlet temperature is 250°C. Therefore, the inlet temperature in this example can preferably be selected as 250°C.

[0085] Example 6

[0086] A method for determining trimethyl phosphate in textiles given in this example is the same as that in Example 1, except that the pure cotton fabric positive sample in step S3 is changed, and three levels of trimethyl phosphate standard solutions are added to the pure cotton fabric without trimethyl phosphate to make the trimethyl phosphate content in the sample 200, 600, and 1000 mg / kg respectively to evaluate the recovery rate and relative standard deviation. The results are shown in Table 2.

[0087] As shown in Table 2, when the trimethyl phosphate content in the sample is 200 mg / kg, the recovery rate of trimethyl phosphate is 93.1% and the relative standard deviation is 6.5%. When the trimethyl phosphate content in the sample is 600 mg / kg, the recovery rate of trimethyl phosphate is 96.4% and the relative standard deviation is 5.2%. When the trimethyl phosphate content in the sample is 1000 mg / kg, the recovery rate of trimethyl phosphate is 95.6% and the relative standard deviation is 5.1%. That is to say, the recovery rate is 93.1% - 96.4% and the relative standard deviation is 5.1% - 6.5%. The determination method in this example can achieve the determination of trimethyl phosphate in textiles, with a relatively high accuracy and meeting the requirements of daily detection.

[0088] Table 2 Recovery rate and precision of trimethyl phosphate in textiles

[0089]

[0090] It should be noted that the above embodiments are all described by taking pure cotton textiles as an example. In other embodiments, trimethyl phosphate in other textiles such as silk textiles or polyester fibers can also be determined, and the detection methods are the same, which will not be listed one by one here.

[0091] It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present disclosure. However, the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also regarded as the protection scope of the present disclosure.

Claims

1. A method for determining trimethyl phosphate in textiles, characterized in that: The determination method comprises: Dissolve trimethyl phosphate with ether in a volumetric flask and dilute to volume to obtain a standard stock solution; The standard stock solution was diluted with ether to form standard solutions of different concentrations, and the response value was measured by gas chromatography-mass spectrometry, and a standard curve correlating the concentration and the response value was proposed; Soaking the textile sample in the standard stock solution, periodically stirring the solution to allow trimethyl phosphate to evenly adhere to the textile sample, and drying the textile sample when the standard stock solution evaporates to near dryness to obtain a textile positive sample; The textile positive sample is cut into pieces and placed in an extraction reactor, an extraction solvent is added for extraction, and after cooling to room temperature, the pieces are filtered through a filter membrane and analyzed using a gas chromatography-mass spectrometer to determine the content of trimethyl phosphate in the textile positive sample according to a standard curve.

2. The measuring method according to claim 1, characterized in that In the standard stock solution, the mass concentration of trimethyl phosphate is 1000 μg / mL.

3. The measuring method according to claim 1, characterized in that The concentration range of the standard solution is 10-50 μg / mL.

4. The measuring method according to claim 1, characterized in that The textile sample is immersed in the standard stock solution, and the solution is stirred for 20 minutes each time.

5. The measuring method according to claim 1, characterized in that The textile samples were dried at 80°C for 1 h.

6. The measuring method according to claim 1, characterized in that The solid-liquid ratio of the textile positive sample placed in the extraction reactor to the extraction solvent is 1: (10-30) g / mL.

7. The measuring method according to claim 1, characterized in that The extraction temperature is 35-45°C, and the extraction time is 55-70 minutes.

8. The measuring method according to claim 1, characterized in that The pore size of the filter membrane is 0.4-0.5 μm.

9. The measuring method according to claim 1, characterized in that The extraction solvent is methanol or acetone; and / or, The extraction method is ultrasonic extraction.

10. The measuring method according to claim 1, characterized in that The parameters of the gas chromatography-mass spectrometry instrument are as follows: The column specifications are 30m×0.25mm×0.25μm; The injection port temperature was 250 °C; The mass spectrometer interface temperature was 280°C; The ion source temperature was 290 °C; The quadrupole temperature is 150°C; Heating program: 60℃ for 1 min, increase the temperature to 100℃ at 10℃ / min, maintain for 1 min, increase the temperature to 220℃ at 30℃ / min, maintain for 1 min; Ionization method: EI source; Injection mode: pulse splitless injection; The pulse pressure was 45 psi.

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