阅读说明：本技术 高效液相色谱法测试丁羟推进剂中酯类增塑剂含量的方法 (Method for testing content of ester plasticizer in butylated hydroxytoluene propellant by high performance liquid chromatography ) 是由 冯晓欢 徐红菊 黄水生 闫志佳 王娜 廖建苹 王艳艳 吴涛 于 2020-12-10 设计创作，主要内容包括：本发明公开了一种高效液相色谱法测试丁羟推进剂中酯类增塑剂含量的方法,先将推进剂试样切成颗粒,精确称量后加入溶剂中进行溶解提取,制备得到样品溶液；然后精确称取一定量增塑剂标准样品,置于容量瓶中,分别加入溶剂溶解、稀释和定容摇匀,配制成具有浓度梯度的已知准确浓度的标准溶液；最后将标准溶液和样品溶液分别利用高效液相色谱仪进行测试,以峰面积为纵坐标、浓度为横坐标,对标准溶液进行线性拟合,得到标准工作曲线,将样品溶液测试的数据代入标准工作曲线中进行计算,得到样品溶液中各增塑剂的含量。该方法有较高的灵敏度,可满足快速准确分析的要求。(The invention discloses a method for testing the content of ester plasticizer in a butylated hydroxytoluene propellant by high performance liquid chromatography, which comprises the steps of cutting a propellant sample into particles, accurately weighing the particles, adding the particles into a solvent, dissolving and extracting the particles to prepare a sample solution; then accurately weighing a certain amount of plasticizer standard sample, placing the plasticizer standard sample in a volumetric flask, respectively adding a solvent for dissolution, dilution and constant volume shaking up, and preparing a standard solution with a concentration gradient and known accurate concentration; and finally, respectively testing the standard solution and the sample solution by using a high performance liquid chromatograph, carrying out linear fitting on the standard solution by taking the peak area as a vertical coordinate and the concentration as a horizontal coordinate to obtain a standard working curve, and substituting the test data of the sample solution into the standard working curve to calculate to obtain the content of each plasticizer in the sample solution. The method has higher sensitivity and can meet the requirement of rapid and accurate analysis.)

1. A method for testing the content of ester plasticizer in a butylated hydroxytoluene propellant by using a high performance liquid chromatography method is characterized by comprising the following steps:

s1, cutting the propellant sample into particles, accurately weighing, adding a solvent for extraction, and fixing the volume to obtain a sample solution;

s2, accurately weighing a certain amount of plasticizer standard sample, placing the plasticizer standard sample in a volumetric flask, respectively adding a solvent for dissolution, dilution and constant volume shaking up, and preparing a standard solution with a concentration gradient and known accurate concentration;

and S3, testing the standard solution and the sample solution by using a high performance liquid chromatograph respectively, performing linear fitting on the standard solution by taking the peak area as a vertical coordinate and the concentration as a horizontal coordinate to obtain a standard working curve, and substituting the data of the sample solution test into the standard working curve to calculate to obtain the content of each plasticizer in the sample solution.

2. The method of claim 1, wherein: the ester plasticizer in the hydroxyl-terminated butyl propellant comprises diisooctyl sebacate and/or di (2-ethyl) hexyl adipate.

3. The method of claim 1, wherein: in S1, a sample solution is prepared by Soxhlet extraction and extracted at 110-130 ℃ for more than 6 h.

4. The method of claim 3, wherein: in S1, a sample solution is prepared by Soxhlet extraction and extracted at 120 ℃ for 6 h.

5. The method according to claim 3 or 4, characterized in that: wrapping the chopped propellant particles with degreasing filter paper, placing the wrapped propellant particles into an extraction tube of a Soxhlet extractor, adding a solvent into an extraction bottle for extraction, removing the filter paper bag after extraction is finished, washing the extraction tube with the solvent and collecting the washed propellant particles in the extraction bottle, volatilizing and concentrating the liquid in the extraction bottle, transferring the liquid into a volumetric flask, washing the extraction bottle, and finally fixing the volume to obtain a sample solution.

6. The method of claim 1, wherein: the solvent used in S1 and S2 was methanol.

7. The method of claim 1, wherein: when the high performance liquid chromatograph is used for testing in S3, the mobile phase is a mixed solution of methanol and water, wherein the volume ratio of the methanol to the water is 95: 5.

8. The method of claim 1, wherein: and filtering the standard solution and the sample solution in S3 with a 0.45 mu m filter membrane before testing.

9. The method of claim 1, wherein: detection wavelength at test in S3: 210 nm; a chromatographic column: c18 (4.6X 150 mm); column temperature: 35 ℃ is carried out.

10. The method of claim 1, wherein: flow rate at test in S3: 1.0mL/min, sample size: 5 muL.

Technical Field

The invention relates to the field of composite solid propellants, in particular to a method for testing the content of ester plasticizers in a butylated hydroxytoluene propellant by using a high performance liquid chromatography.

Background

The composite solid propellant is one of the main power sources of the high-energy and long-range solid missile. Among them, the butyl hydroxyl propellant is still the most widely used propellant variety for a long time due to the comprehensive advantages of the butyl hydroxyl propellant in the aspects of energy performance, mechanical property, combustion performance, safety performance, storage performance, cost and the like.

The plasticizer is one of the key components of the composite solid propellant, and the existing method for measuring the content of the plasticizer of the propellant comprises a weighing method,¹⁴The conditions of low test accuracy, high requirements on instrument conditions, high test cost and the like exist in the C tracing technology, the coating charge test and the like.

Disclosure of Invention

The invention provides a method for testing the content of ester plasticizer in a butylated hydroxytoluene propellant by using a high performance liquid chromatography, which has high sensitivity and can meet the requirement of rapid and accurate analysis.

The technical scheme of the invention is that the method for testing the content of the ester plasticizer in the butylated hydroxytoluene propellant by using the high performance liquid chromatography comprises the following steps:

s1, cutting the propellant sample into particles, accurately weighing, adding a solvent for extraction, and fixing the volume to obtain a sample solution;

s2, accurately weighing a certain amount of plasticizer standard sample, placing the plasticizer standard sample in a volumetric flask, respectively adding a solvent for dissolution, dilution and constant volume shaking up, and preparing a standard solution with a concentration gradient and known accurate concentration;

and S3, testing the standard solution and the sample solution by using a high performance liquid chromatograph respectively, performing linear fitting on the standard solution by taking the peak area as a vertical coordinate and the concentration as a horizontal coordinate to obtain a standard working curve, and substituting the data of the sample solution test into the standard working curve to calculate to obtain the content of each plasticizer in the sample solution.

Further, the ester plasticizer in the hydroxyl-terminated butyl propellant comprises diisooctyl sebacate (DOS) and/or di (2-ethyl) hexyl adipate (DEHA).

Further, in S1, a sample solution is prepared by Soxhlet extraction, and the extraction is carried out at 110-130 ℃ for more than 6 h.

Further, a sample solution was prepared by Soxhlet extraction in S1, and extracted at 120 ℃ for 6 hours.

Further, wrapping the chopped propellant particles with degreasing filter paper, placing the wrapped propellant particles into an extraction tube of a Soxhlet extractor, adding a solvent into an extraction bottle for extraction, removing the filter paper bag after extraction is finished, washing the extraction tube with the solvent and collecting the washed propellant particles in the extraction bottle, volatilizing and concentrating liquid in the extraction bottle, transferring the liquid into a volumetric flask, washing the extraction bottle, and finally fixing the volume to obtain a sample solution.

Further, the solvent used in S1 and S2 was methanol.

Further, when the test is performed by using a high performance liquid chromatograph in S3, the mobile phase is a mixture of methanol and water, wherein the volume ratio of methanol to water is 95: 5.

Further, the standard solution and the sample solution in S3 were filtered through a 0.45 μm filter before testing. Detection wavelength at test in S3: 210 nm; a chromatographic column: c18 (4.6X 150 mm); column temperature: 35 ℃ is carried out. Flow rate during test: 1.0mL/min, sample size: 5 μ L.

The invention also has the following beneficial effects:

when the sample solution is prepared, the plasticizer in the propellant is extracted by a Soxhlet extraction method, so that the temperature and the purity of the extracting solution during the extraction of the plasticizer in the propellant can be ensured, the extraction efficiency of a target object is improved, and the extraction effect is ensured. Compared with 2 extraction modes such as soaking, Soxhlet extraction and the like, the extraction effect is better when the Soxhlet extraction is used, and in addition, the methanol is used as the extraction solvent, so the extraction effect is optimal.

The DOS and DEHA ester plasticizers have obvious ultraviolet characteristic absorption, and can be distinguished from other interference components by controlling appropriate detection conditions by applying a reversed phase liquid chromatography and ultraviolet detector combination instrument. The invention adopts a high performance liquid chromatography analysis technology combined with a Soxhlet extraction pretreatment technology to carry out a series of researches on extraction, qualification and quantification of a target object, and finally establishes a detection and analysis method for the content of ester plasticizer in the butylated hydroxytoluene propellant. The method has higher sensitivity, can meet the requirement of rapid and accurate analysis, and is suitable for detecting and analyzing the content of the ester plasticizer in the composite solid propellant.

Drawings

FIG. 1 is a chromatogram of standard solutions of 2 ester plasticizers in example 1 at different concentrations, wherein 1 is DEHA and 2 is DOS.

FIG. 2 is a standard curve plotted with the area of the peak of the standard sample as the ordinate and the concentration as the abscissa in the standard solution in example 1. Wherein 1 is DEHA; 2 is DOS.

FIG. 3 is a chromatogram of sample solution TJJ-DOS-1# -TJJ-DOS-3 #.

FIG. 4 is a chromatogram of sample solution TJJ-DEHA-1# -TJJ-DEHA-3 #.

FIG. 5 is a graph showing the effect of different detection wavelengths on the analysis results

FIG. 6 is a graph showing the effect of different flow rates on the results of the analysis.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention.

Example 1:

the propellant sample to be tested is a finished product medicament of the butylated hydroxytoluene propellant.

The specific testing steps are as follows:

(1) preparation of a detection sample: the butylated hydroxyl propellant was harvested and the propellant samples were cut into particles as small as possible for use. Packing the weighed sample in a degreasing filter paper bag, wherein the weighing amount is 3.0000 g; placing in an extraction tube of a Soxhlet extractor. Adding about 200mL of methanol into an extraction bottle, connecting each part of the Soxhlet extractor without air leakage, opening circulating water, and heating and extracting for 6h in a constant-temperature electric heating jacket at 120 ℃.

(2) Selection of liquid phase test conditions: the method comprises the following steps of carrying out quantitative test on test conditions such as different mobile phases, different proportions, different wavelengths, different chromatographic columns, different flow rates and the like, and finally determining the test conditions of the high performance liquid chromatography from factors such as separation effect, experimental verification result and the like: the volume ratio of the methanol to the ultrapure water is 95: 5; detection wavelength: 210 nm; a chromatographic column: c18 (4.6X 150 mm); column temperature: 35 ℃; flow rate: 1.0mL/min, sample size: 5 μ L.

(3) Drawing an external standard calibration curve: quantitative determination is carried out by adopting an external standard calibration curve method, a certain amount of DOS and DEHA standard samples are weighed, placed in a volumetric flask, dissolved, diluted and uniformly shaken with methanol to prepare standard solutions with known accurate concentrations, and linear fitting is carried out according to the high performance liquid chromatography test conditions to obtain chromatograms as shown in figure 1, with peak areas as vertical coordinates and concentrations as horizontal coordinates, so as to respectively obtain linear regression equations and correlation coefficients of 2 ester plasticizers, specifically shown in figure 2 and table 1. The result shows that the linear relation of the standard curve is good, and the correlation coefficient R is good²Are all greater than 0.999.

TABLE 12 Standard working curves, correlation coefficients for the plasticizers

(4) Testing of sample solutions and calculation of results

Randomly selecting 3 batches of butylated hydroxytoluene propellant samples containing DOS and DEHA plasticizers, and carrying out plasticizer content test, wherein the spectrograms are shown in figures 3 and 4, wherein TJJ-DOS-1# -TJJ-DOS-3 #, and DOS plasticizer is added; TJJ-DEHA-1# -TJJ-DEHA-3 #, and DEHA plasticizer is added; the test results are shown in the following tables 2, 6 groups of samples, and the test results have parallel difference less than 0.3.

TABLE 2 determination of plasticizer content in sample solutions

(5) Recovery and precision

Taking samples subjected to extraction treatment, respectively adding a certain amount of standard solution, carrying out determination according to the high performance liquid chromatography test conditions, carrying out parallel determination 6 times on each sample, and calculating the average recovery rate and the relative standard deviation of 2 ester plasticizers, wherein the results are shown in the following table 3.

Table 3 recovery rate test results table (n ═ 6)

The result shows that the standard recovery rate of the method is between 98.98% and 99.53%, and the measured relative standard deviation of the 2 ester plasticizers is less than 5%, which indicates that the method has high accuracy and precision.

At present, the test method is applied for multiple times, the test result is accurate and effective, the test efficiency is high, and the requirement of rapid and accurate analysis can be met.

Optimization of test methods

(1) Selection of extraction mode

Under the condition of keeping the extraction solvent, the extraction time and the volume of the extracting solution consistent, 2 extraction modes such as soaking, Soxhlet extraction and the like are compared, and the measurement results are shown in Table 1. The results show that the Soxhlet extraction method is selected because the Soxhlet extraction method has a good extraction effect and the measured values of DOS and DEHA are 28.11 and 30.85mg/g, respectively.

TABLE 4 influence of different extraction methods on the extraction results

(2) Selection of extraction solvent

On the premise of keeping the extraction mode, extraction time and volume of the extraction solvent consistent, the same sample was treated with 4 different solvents (methanol, acetonitrile, acetone and tetrahydrofuran), and the measurement results are shown in table 5 below. The results show that methanol is used as the extraction solvent, the extraction effect is best, and the measured values of DOS and DEHA are respectively 28.11 mg/g and 30.85mg/g, so the extraction solvent is selected from methanol.

TABLE 5 Effect of different extraction solvents on the extraction results

(3) Volume ratio of mobile phase

The results of 2 ester plasticizers are shown in Table 6 when the mobile phase is methanol-water solution with different volume ratio. The results show that in a methanol-water solution volume ratio of 95:5, the separation results are best, the measured values of DOS and DEHA are 28.11 and 30.85mg/g, respectively, so the mobile phase is selected from 95:5 methanol-water solution.

TABLE 6 influence of different volume ratios of methanol-water solution on the analytical results

(4) Detection wavelength

The characteristic absorption peaks of 2 ester plasticizers were examined for absorption intensities at 210, 230 and 280nm, and the results are shown in FIG. 5. The result shows that the response value of the chromatographic peak at 210nm is the largest, 230nm is weaker, 280nm has no response, and therefore the detection wavelength is selected to be 210 nm.

(5) Detecting the flow velocity

And (3) under the condition of keeping the consistency of the extraction solvent, the extraction mode, the volume ratio of the mobile phase and the detection wavelength, investigating the influence of different flow rates on the analysis result of the same sample. For this sample, flow rates of 0.8ml/min, 0.9ml/min, and 1ml/min were selected for test analysis, and the results of the analysis are shown in FIG. 6. The results show that a flow rate of 1ml/min is preferable, and therefore this flow rate is selected.