Method for detecting caprolactam in polyether sulfone filter membrane and application of method

Abstract

The invention belongs to the field of organic matter detection, and particularly relates to a method for detecting caprolactam in a polyether sulfone filter membrane and application of the method. Comprising the following steps that a polyether sulfone filter membrane is soaked, caprolactam is extracted, a to-be-detected solution is obtained, GC / MS is adopted for analyzing and detecting the to-be-detected solution, and a chromatographic column adopted by GC / MS is TG-5MS. Compared with the prior art, the method for detecting the content of caprolactam in the filter membrane material through a gas chromatograph-mass spectrometer and a chromatographic column TG-5MS has feasibility, the blank of related detection methods is filled, and the result shows that the recovery rate of caprolactam in the method is 96.5%-113.0%; the concentration of caprolactam in the range of 5-400 mg / L is in direct proportion to the peak area, the linear correlation coefficient is larger than 0.99, the linear relation is good, the detection time is within 15 min, the detection result is accurate, and practicability is high.

Description

Technical Field

[0001] The invention belongs to the field of organic matter detection, and specifically relates to a method for detecting caprolactam in a polyethersulfone filter membrane and application thereof. Background Art

[0002] Polyethersulfone membranes are widely used in the pharmaceutical industry, but polyethersulfone membrane additives include caprolactam, which is a low-toxic substance. Frequent contact with caprolactam can cause headaches, dizziness, fatigue, memory loss, sleep disorders and other neurasthenia symptoms. Caprolactam monomers have strong hygroscopicity and are easily soluble in sebum, so they can be absorbed by the skin and easily cause skin damage when in contact, such as smooth and dry skin, thickening of the stratum corneum, skin cracking, desquamation, etc., and sometimes systemic dermatitis may occur.

[0003] Patent CN105548408A discloses a method for detecting caprolactam in nylon textiles. The invention discloses a method for detecting caprolactam in nylon textiles. The nylon textiles are treated to obtain nylon textile fragments; a certain amount of nylon textile fragments are weighed, and double distilled water is added, and the fragments are treated at a constant temperature of 80-120°C in an oven for 45-90 minutes; the fragments are treated with ultrasound in an ultrasonic cleaner for 20-50 minutes, and the fragments are taken out and cooled to room temperature, and the supernatant is filtered through a water filter membrane after being shaken and filtered to obtain a test liquid; and the content of caprolactam in the test liquid is determined by an ultra-high performance liquid chromatography triple quadrupole mass spectrometer. However, the detection method of this patent is liquid-mass spectrometry, which requires a relatively cumbersome pre-treatment step and is time-consuming, which is not conducive to obtaining the test results in a short time. Patent CN102288697B discloses a method for determining the content of caprolactam in air and waste gas, which is specifically detected by gas chromatograph. The precision and accuracy of this method are less than 10%, and the detection limit is 1.3μg / mL. However, this method is suitable for the determination of the content of caprolactam in gas, but not for polyethersulfone filter membranes, and there is no mass spectrometry connection, so it is impossible to perform real-time quantification. Therefore, it is of great practical significance to establish a caprolactam detection technology in polyethersulfone filter membranes.

[0004] When the domestic gas chromatography-mass spectrometer uses the chromatographic column TG-5MS to detect the content of caprolactam, the setting method of the gas phase and mass spectrometry parameters has blank characteristics. Therefore, it is urgent to establish a detection method for the content of caprolactam in polyethersulfone filter membrane using the chromatographic column TG-5MS. Summary of the invention

[0005] The purpose of the present invention is to solve at least one of the above problems and to provide a method for detecting caprolactam in a polyethersulfone filter membrane and its application, so as to solve the problem that there is no method for detecting the caprolactam content in the prior art using a gas chromatography-mass spectrometer using a chromatographic column TG-5MS, thereby realizing the use of a chromatographic column TG-5MS to detect the caprolactam content in a polyethersulfone filter membrane.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] One of the technical solutions of the present invention is to provide a method for detecting caprolactam in a polyethersulfone filter membrane, comprising the following steps: extracting caprolactam from the polyethersulfone filter membrane to obtain a test solution, and using GC / MS to analyze and detect the test solution, wherein the chromatographic column used in the GC / MS is TG-5MS;

[0008] The gas chromatography parameters of the GC / MS are set as follows: column temperature: 100-220°C; injection port temperature: 220-250°C; injection volume: 0.5-2 μL; flow rate: 0.5-1.5 mL / min; ion source: EI source, ion source temperature: 200-300°C;

[0009] The mass spectrometry parameters of the GC / MS were set as follows: mass spectrometry interface temperature: 250-300°C; solvent delay time: 2-5 min; scanning mode: SIM; retention time: 4-6 min; quantitative ion 113; qualitative ions 55, 84.

[0010] Further, the gas chromatography parameters of the GC / MS are set as follows: column temperature: 100-220°C; injection port temperature: 220°C; injection volume: 1 μL; flow rate: 1 mL / min; ion source: EI source, ion source temperature: 220°C;

[0011] The mass spectrometry parameters of the GC / MS were set as follows: mass spectrometry interface temperature: 280° C.; solvent delay time: 3 min; scanning mode: SIM; retention time: 5.33 min; quantitative ions 113; and qualitative ions 55 and 84.

[0012] Furthermore, the temperature raising program of the gas chromatography column of the GC / MS is as follows: the initial temperature is 100° C., and after maintaining for 2 minutes, the temperature is raised to 220° C. at a rate of 20° C. / min for injection.

[0013] Furthermore, the volume ratio of ethyl acetate to n-hexane is 3:1.

[0014] Furthermore, the polyethersulfone filter membrane is soaked in ethanol, and then a mixed solution of ethyl acetate and n-hexane is added for extraction, and the upper layer of the extracted liquid is dried to remove water to obtain a test solution.

[0015] Furthermore, the immersion ratio of the polyethersulfone filter membrane to ethanol = (10-15) cm 2 :(1-5)mL, preferably 13cm 2 :3mL.

[0016] Furthermore, the polyethersulfone filter membrane is soaked in 50% ethanol for 18-30 hours, preferably 24 hours, to extract caprolactam.

[0017] Furthermore, the extraction is an equal-proportional extraction.

[0018] Furthermore, the volume ratio of the mixed solution of 50% ethanol, ethyl acetate and n-hexane is 1:1.

[0019] Further, anhydrous magnesium sulfate is added to the upper liquid to dry and remove water.

[0020] Furthermore, the time for the GC / MS to detect caprolactam is less than 15 minutes.

[0021] Furthermore, during the determination process, the test liquid is first subjected to a GC / MS preliminary experimental analysis to obtain a response signal, and a series of standard working solutions with concentration gradients are configured according to the caprolactam concentration corresponding to the response value selected according to the response signal, and the caprolactam concentration in the test liquid is calculated based on the determination results of the standard working solution.

[0022] One of the technical solutions of the present invention is to provide an application of the above-mentioned detection method in the detection of caprolactam in a polyethersulfone filter membrane.

[0023] Furthermore, the applications include applications in the pharmaceutical field and the environmental monitoring field.

[0024] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. The present invention is the first to apply the detection technology of gas phase and mass spectrometry using a chromatographic column TG-5MS in GC / MS to the detection of caprolactam, and the results show that the recovery rate of caprolactam in the present invention is 96.5% to 113.0%; the concentration of caprolactam in the range of 5 mg / L to 400 mg / L is proportional to the peak area, the linear correlation coefficient is greater than 0.99, and the linear relationship is good, indicating that the determination method and parameter selection in the present invention can be well applied to the detection of caprolactam of different concentrations.

[0027] 2. The preparation method of the polyethersulfone filter membrane in the present invention is simple, the detection time of gas chromatography-mass spectrometry is short, the detection time is within 15 minutes, and the detection result is accurate and practical.

[0028] 3. The method of the present invention for detecting the content of caprolactam in the filter membrane material by using a gas chromatography-mass spectrometer and a chromatographic column TG-5MS is feasible, filling the gap in related detection methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The chromatogram is the blank control of Example 1.

[0030] Figure 2 It is the chromatogram of the standard working solution of Example 1.

[0031] Figure 3 The chromatogram of the test solution of Example 1.

[0032] Figure 4 This is a standard curve diagram of caprolactam during the detection process of Example 1. DETAILED DESCRIPTION

[0033] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0034] Unless otherwise specified, the experimental reagents and raw materials used in the present invention are commercially available.

[0035] The experimental methods without specific conditions in the following implementations are all selected according to conventional methods and conditions, or according to the product specifications. Unless otherwise specified, the experimental instruments used in the present invention are all conventional experimental instruments in the laboratory. The present invention is further explained below in conjunction with the embodiments and the accompanying drawings.

[0036] Example 1

[0037] This embodiment provides a method for detecting caprolactam in a polyethersulfone filter membrane, and the specific parameters are as follows:

[0038] Detection equipment: Thermo Fisher Scientific TRACE 1300-ISQ7000; detection parameters are set as follows:

[0039] The test solution was analyzed and detected by GC / MS, and the chromatographic column used by the GC / MS was TG-5MS;

[0040] The gas chromatography parameters of the GC / MS were set as follows: column temperature: 100-220°C; injection port temperature: 220°C; injection volume: 1 μL; flow rate: 1 mL / min; ion source: EI source, ion source temperature: 220°C;

[0041] The temperature program of the gas chromatography column of the GC / MS is as follows: the initial temperature is 100°C, and after maintaining for 2 minutes, the temperature is increased to 220°C at a rate of 20°C / min for injection;

[0042] The mass spectrometry parameters of the GC / MS were set as follows: mass spectrometry interface temperature: 280° C.; solvent delay time: 3 min; scanning mode: SIM; retention time: 5.33 min; quantitative ions 113; and qualitative ions 55 and 84.

[0043] 1. Sample preparation

[0044] Cut 6500cm 2 Place the polyethersulfone filter membrane in a clean container and add 1500mL of 50% ethanol extract respectively. The filter membrane should be completely immersed in the extract; put another 1500mL of 50% ethanol extract without contacting the filter membrane as a blank control; shake the filter membrane appropriately at room temperature and keep it in contact for 24 hours.

[0045] Take 10 ml of the extract and use a mixed solution of ethyl acetate and n-hexane (V 乙酸乙酯 :V 正己烷 =3:1) extract the extract in equal proportions, transfer the upper liquid to a clean glass sample bottle, add anhydrous magnesium sulfate to dry and remove water, and take the upper organic phase as the test solution.

[0046] 2. Determination of standard curve

[0047] The obtained test liquid is analyzed and detected by GC / MS. First, the test liquid is analyzed on the machine to obtain the response signal of caprolactam in the test liquid. The response value range is selected according to the response signal in the test liquid, and then the caprolactam standard working solution of the response concentration is selected for preparation, and the standard working solution is analyzed by GC / MS.

[0048] The standard working solution selected in this embodiment includes 5 concentration gradients, namely 5 mg / L, 10 mg / L, 50 mg / L, 100 mg / L, and 400 mg / L. In addition, a blank control is set, and the caprolactam concentration in the blank control is 0 mg / L.

[0049] The above-mentioned determination conditions were used to perform GC / MS detection on the above-mentioned 5 concentration standard working solutions and draw a standard curve. The detection results are shown in Table 1:

[0050] Table 1 Test results of linear range of caprolactam reference series concentration

[0051]

[0052] According to the data in Table 1, a standard working curve is drawn with concentration as the horizontal axis and peak area as the vertical axis, as shown in Figure 1 As shown, Figure 1 This is the standard curve of caprolactam.

[0053] The quantitative limit of the standard working solution is 5 mg / L, and the signal-to-noise ratio is 79.1. The concentration of caprolactam is proportional to its peak area in the linear concentration range of 5 mg / L-400 mg / L, and the correlation coefficient is greater than 0.99, indicating a good linear relationship.

[0054] 3. Recovery rate and repeatability experiment

[0055] (1) Recovery rate experiment

[0056] The caprolactam standard working solution with the above concentrations of 5 mg / L, 50 mg / L and 400 mg / L was measured three times according to the above measurement conditions, and the peak area RSD (%) was calculated. The experimental results are shown in Table 2.

[0057] Table 2 Caprolactam accuracy (recovery) test results of three different concentrations

[0058]

[0059] (2) Repeatability experiment

[0060] The above-mentioned caprolactam standard working solution with a concentration of 50 mg / L was repeatedly measured 6 times according to the above-mentioned measurement conditions, and its peak area RSD (%) was calculated. The experimental results are shown in Table 3.

[0061] Table 3 Caprolactam repeatability test results

[0062]

[0063] It can be seen from Tables 1 and 2 above that the RSD values ​​of the obtained results meet the requirements of the recovery limit of 80%-115% in the "Guidelines for Validation of Analytical Methods" in the "Chinese Pharmacopoeia", indicating that the determination method has good precision and can meet the analysis requirements of caprolactam.

[0064] 4. Test results

[0065] The quantitative results of polyethersulfone filter membrane are shown in Table 4.

[0066] Table 4 Detection results of caprolactam in polyethersulfone filter membrane

[0067]

[0068] The test results show that 235 mg / L of caprolactam was detected in the ethanol solution, that is, 0.05 mg / cm2 of caprolactam was detected in the polyethersulfone filter membrane. 2 .

[0069] Example 2

[0070] This embodiment provides a method for detecting caprolactam in a polyethersulfone filter membrane, and the specific detection parameters are set as follows:

[0071] The test solution was analyzed and detected by GC / MS, and the chromatographic column used by the GC / MS was TG-5MS;

[0072] The gas chromatography parameters of the GC / MS were set as follows: column temperature: 100-220°C; injection port temperature: 250°C; injection volume: 0.8 μL; flow rate: 1.2 mL / min; ion source: EI source, ion source temperature: 220°C;

[0073] The temperature program of the gas chromatography column of the GC / MS is as follows: the initial temperature is 100°C, and after maintaining for 2 minutes, the temperature is increased to 220°C at a rate of 20°C / min for injection;

[0074] The mass spectrometry parameters of the GC / MS were set as follows: mass spectrometry interface temperature: 280° C.; solvent delay time: 3 min; scanning mode: SIM; retention time: 5.33 min; quantitative ions 113; and qualitative ions 55 and 84.

[0075] The measurement results of Example 2 are close to those of Example 1.

[0076] Example 3

[0077] This embodiment provides a method for detecting caprolactam in a polyethersulfone filter membrane, and the specific detection parameters are set as follows:

[0078] The test solution was analyzed and detected by GC / MS, and the chromatographic column used by the GC / MS was TG-5MS;

[0079] The gas chromatography parameters of the GC / MS were set as follows: column temperature: 100-220°C; injection port temperature: 220°C; injection volume: 1 μL; flow rate: 1 mL / min; ion source: EI source, ion source temperature: 220°C;

[0080] The temperature program of the gas chromatography column of the GC / MS is as follows: the initial temperature is 100°C, and after maintaining for 2 minutes, the temperature is increased to 220°C at a rate of 20°C / min for injection;

[0081] The mass spectrometry parameters of the GC / MS were set as follows: mass spectrometry interface temperature: 300° C.; solvent delay time: 4 min; scanning mode: SIM; retention time: 5.33 min; quantitative ions 113; and qualitative ions 55 and 84.

[0082] The measurement results of Example 3 are close to those of Example 1.

[0083] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A method for detecting caprolactam in a polyethersulfone filter membrane, characterized in that: The method comprises the following steps: extracting caprolactam from a polyethersulfone filter membrane to obtain a test solution, and using GC / MS to analyze and detect the test solution, wherein the chromatographic column used in the GC / MS is TG-5MS; The gas chromatography parameters of the GC / MS are set as follows: column temperature: 100-220°C; injection port temperature: 220-250°C; injection volume: 0.5-2 μL; flow rate: 0.5-1.5 mL / min; ion source: EI source, ion source temperature: 200-300°C; The mass spectrometry parameters of the GC / MS were set as follows: mass spectrometry interface temperature: 250-300°C; solvent delay time: 2-5 min; scanning mode: SIM; retention time: 4-6 min; quantitative ion 113; qualitative ions 55, 84.

2. The method for detecting caprolactam in a polyethersulfone filter membrane according to claim 1, characterized in that: The gas chromatography parameters of the GC / MS were set as follows: column temperature: 100-220°C; injection port temperature: 220°C; injection volume: 1 μL; flow rate: 1 mL / min; ion source: EI source, ion source temperature: 220°C; The mass spectrometry parameters of the GC / MS were set as follows: mass spectrometry interface temperature: 280° C.; solvent delay time: 3 min; scanning mode: SIM; retention time: 5.33 min; quantitative ions 113; and qualitative ions 55 and 84.

3. The method for detecting caprolactam in a polyethersulfone filter membrane according to claim 1, characterized in that: The temperature program of the gas chromatography column of the GC / MS is as follows: the initial temperature is 100° C., and after maintaining for 2 minutes, the temperature is increased to 220° C. at a rate of 20° C. / min and then sample is injected.

4. The method for detecting caprolactam in a polyethersulfone filter membrane according to claim 1, characterized in that: The polyethersulfone filter membrane is soaked in ethanol, and then a mixed solution of ethyl acetate and n-hexane is added for extraction. The upper layer of the extracted liquid is dried to remove water to obtain a test solution.

5. The method for detecting caprolactam in a polyethersulfone filter membrane according to claim 4, characterized in that: The immersion ratio of the polyethersulfone filter membrane to ethanol = (10-15) cm 2 :(1-5)mL.

6. The method for detecting caprolactam in a polyethersulfone filter membrane according to claim 4, characterized in that: The polyethersulfone filter membrane is soaked in 50% ethanol for 18-30 hours to extract caprolactam.

7. The method for detecting caprolactam in a polyethersulfone filter membrane according to claim 4, characterized in that: The volume ratio of ethyl acetate to n-hexane is 3:

1.

8. The method for detecting caprolactam in a polyethersulfone filter membrane according to claim 4, characterized in that: The upper layer was dried and dehydrated by adding anhydrous magnesium sulfate.

9. The method for detecting caprolactam in a polyethersulfone filter membrane according to claim 1, characterized in that: The time for the GC / MS to detect caprolactam is less than 15 minutes.

10. Use of the method for detecting caprolactam in a polyethersulfone filter membrane as claimed in claim 1.

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