Method for determining content of HAN and hydroxyethyl hydrazine nitrate in hydroxylamine nitrate propellant

Abstract

The invention provides a capillary electrophoresis detection method for a hydroxylamine nitrate propellant, and particularly provides a capillary electrophoresis internal standard method for determining the content of HAN and hydroxyethylhydrazine nitrate in a non-toxic propellant, the used internal standard substance is an aminoguanidine salt compound, and the separation conditions of capillary electrophoresis are as follows: the total length range of a quartz capillary is 40-100cm, the total length range of the quartz capillary is 40-100cm, and the total length range of the quartz capillary is 40-100cm; and the inner diameter range of the column is 50-100 microns. The use voltage of the capillary electrophoresis used in the invention is 15-45kV. The capillary electrophoresis adopts pressure sample introduction, the sample introduction pressure range is 0.1-1.0 psi, and the sample introduction time is 1-10 seconds. The detection wavelength used in the invention is ultraviolet 180-220 nm. The buffer solution is a commercially available cation kit.

Description

Technical Field

[0001] The present application relates to the field of propellant detection, and more specifically, to a method for determining the contents of HAN and hydroxyethylhydrazine nitrate in a non-toxic propellant. Background Art

[0002] Liquid monopropellants are widely used in the fields of attitude and orbit control of spacecraft such as rockets, satellites, and spacecraft, as well as emergency power for aircraft. The most widely used liquid monopropellants, such as hydrazine, generally have the disadvantages of high toxicity and environmental pollution. With the improvement of people's environmental awareness and the urgent demand for high-performance propulsion technology, the development of non-toxic, pollution-free, environmentally friendly green new propellants is the main direction of the development of advanced space power. New monopropellants are usually prepared by compounding oxidizers (hydroxylamine nitrate / ammonium dinitramide, etc.) and fuels. Among them, HAN-based propellants have attracted widespread research interest in the United States and Japan due to their high specific impulse and low freezing point. In 2000, the U.S. Air Force led the development of the AF-315 series of monopropellants, which are mainly composed of HAN, hydroxyethylhydrazine nitrate (hydroxyethylhydrazine nitrate (β-HEHN)) and water. Among them, the specific impulse and density specific impulse of AF-315E propellant are 11% and 70% higher than those of hydrazine monopropellants, respectively.

[0003] It has become one of the most attractive alternatives. Domestic institutions such as the Dalian Institute of Chemical Physics have been engaged in the research of green unit propellants since 2000 and have developed a series of HAN-based propellants, including the HAN / hydroxyethyl hydrazine nitrate / water system.

[0004] The stability of the propellant formula has an important impact on its application performance, energy and combustion temperature. Therefore, establishing an analytical method for the content of hydroxylamine nitrate and hydroxyethylhydrazine nitrate in the propellant system has a key impact on the stability control of the propellant during the design and development of the propellant formula, and is also of great significance for the research of new green propellants. However, there is no content on the detection method of HAN and hydroxyethylhydrazine nitrate in HAN-based propellants in existing reports, so it is urgent to develop a simple, fast, accurate and high-precision determination method. Summary of the invention

[0005] In order to solve the existing technical problems, the present application provides a method for detecting the content of HAN and hydroxyethylhydrazine nitrate in non-toxic propellants with quick, simple operation and high accuracy. The method solves the problem of inaccurate determination of the content of HAN and hydroxyethylhydrazine nitrate caused by the difficulty in accurately controlling the injection amount of the external standard method.

[0006] The present invention provides a method for determining the contents of HAN and hydroxyethylhydrazine nitrate in a non-toxic propellant, the method comprising the following steps:

[0007] Step 1: Preparation and detection of standard solution: Place more than 5 different masses of HAN, more than 5 different masses of hydroxyethylhydrazine nitrate, and internal standard in more than 5 volumetric flasks, dilute to the scale with solvent, and shake well to prepare more than 5 parts of HAN and hydroxyethylhydrazine nitrate series standard solutions of different concentrations, and take the series of standard solutions for capillary electrophoresis detection;

[0008] Step 2: Draw a standard curve by the internal standard method, record the peak area of ​​each substance (HAN, hydroxyethyl hydrazine nitrate, internal standard) in the standard solution, use the ratio of the HAN peak area to the internal standard peak area, the ratio of the hydroxyethyl hydrazine nitrate peak area to the internal standard peak area as the abscissa or ordinate, use the ratio of the HAN concentration to the internal standard concentration, the ratio of the hydroxyethyl hydrazine nitrate concentration to the internal standard concentration as the ordinate or abscissa, respectively, and draw the standard curves of HAN and hydroxyethyl hydrazine nitrate respectively;

[0009] Step 3: Preparation and detection of the sample to be tested (non-toxic propellant): Accurately weigh the sample and internal standard into a volumetric flask, dilute to the scale with solvent, shake well and perform capillary electrophoresis detection;

[0010] Step 4: Calculation of HAN and hydroxyethylhydrazine nitrate contents in the sample to be tested: record the peak areas of HAN, hydroxyethylhydrazine nitrate and internal standard in the sample, calculate the ratio of the HAN peak area to the internal standard peak area, the ratio of the hydroxyethylhydrazine nitrate peak area to the internal standard peak area, and obtain the contents of HAN and hydroxyethylhydrazine nitrate through the standard curves of HAN and hydroxyethylhydrazine nitrate respectively;

[0011] Wherein, the internal standard substance is an aminoguanidine salt compound. The preferred internal standard substances are mainly aminoguanidine hydrochloride and aminoguanidine nitrate.

[0012] Further, in the capillary electrophoresis conditions, the total length of the quartz capillary used in the present invention is in the range of 40-100 cm, and the inner diameter of the column is in the range of 50-100 μm. The preferred total length of the quartz capillary is in the range of 40-80 cm, and the inner diameter of the column is in the range of 65-85 μm. The more preferred total length of the quartz capillary is in the range of 60.2 cm, and the inner diameter of the column is in the range of 75 μm.

[0013] Further, in the capillary electrophoresis conditions, the capillary electrophoresis voltage used in the present invention is 15-45 kV. Preferably, the capillary electrophoresis voltage used is 20-40 kV. More preferably, in the capillary electrophoresis conditions, the capillary electrophoresis voltage used in the present invention is 30 kV.

[0014] Further, in the capillary electrophoresis conditions, the capillary electrophoresis of the present invention adopts pressure injection, the injection pressure range is 0.1-1.0 psi, and the injection time is 1-10 seconds. The preferred capillary electrophoresis injection pressure range is 0.3-0.7 psi, and the injection time is 3-7 seconds. The more preferred capillary electrophoresis injection pressure range is 0.5 psi, and the injection time is 5 seconds.

[0015] Furthermore, in the capillary electrophoresis conditions, the detection wavelength used in the present invention is ultraviolet 180-220nm. The preferred capillary electrophoresis detection wavelength is ultraviolet preferably 200nm.

[0016] Furthermore, in the capillary electrophoresis conditions, the capillary electrophoresis buffer used in the present invention is a commercially available cationic kit. The preferred capillary electrophoresis buffer is a cationic kit from Bosiya.

[0017] Preferably, in the capillary electrophoresis conditions of the present invention, the total length of the quartz capillary is in the range of 40-100 cm, and the inner diameter of the column is in the range of 50-100 μm. The voltage used in the capillary electrophoresis used in the present invention is 15-45 kV. The capillary electrophoresis described in the present invention adopts pressure injection, the injection pressure range is 0.1-1.0 psi, and the injection time is 1-10 seconds. The detection wavelength used is 180-220 nm. The buffer is a commercially available cationic reagent kit.

[0018] Further, in the preferred capillary electrophoresis conditions, the total length of the quartz capillary used in the present invention is in the range of 40-80 cm, and the inner diameter of the column is in the range of 65-85 μm. The voltage used for the capillary electrophoresis used in the present invention is 20-40 kV. The capillary electrophoresis described in the present invention adopts pressure injection, the injection pressure range is 0.3-0.7 psi, and the injection time is 3-7 seconds. The detection wavelength used is ultraviolet, preferably 200 nm. The buffer is a commercially available cationic reagent kit.

[0019] In the more preferred capillary electrophoresis conditions, the total length of the quartz capillary used in the present invention is 60.2 cm, and the column inner diameter is 75 μm. The voltage used for the capillary electrophoresis used in the present invention is 30 kV. The capillary electrophoresis described in the present invention adopts pressure injection, the injection pressure range is 0.5 psi, and the injection time is 5 seconds. The detection wavelength used is ultraviolet, preferably 200 nm. The buffer is a cationic reagent kit of Bosiya Company.

[0020] Furthermore, the preparation and detection of the standard solution and the preparation and detection of the sample to be tested are specifically performed in the following steps:

[0021] Weigh (0-60) mg of HAN and (0-60) mg of hydroxyethylhydrazine nitrate in 5 different weights in increasing or decreasing order into 5 100 mL volumetric flasks, add (10-60) mg (preferably (20-30) mg) of internal standard aminoguanidine hydrochloride into the volumetric flasks, dilute to the scale with water, shake well and mix, and prepare 5 series of standard solutions with different concentration gradients for detection.

[0022] Preparation and detection of the sample solution: Accurately weigh (0.05-0.15) g of sample and (10-60) mg (preferably (20-30) mg) of internal standard aminoguanidine hydrochloride into a 100 mL volumetric flask, dilute to the scale with water, shake well and mix before detection.

[0023] The method is simple, reproducible, accurate, and can efficiently and accurately determine the contents of HAN and hydroxyethylhydrazine nitrate in non-toxic propellants, which is of great significance for the detection of non-toxic propellants. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Capillary electrophoresis separation of hydroxylamine nitrate-based propellant and internal standard. DETAILED DESCRIPTION

[0025] Example 1

[0026] The determination of the contents of HAN and hydroxyethylhydrazine nitrate in the non-toxic propellant sample 1# comprises the following steps:

[0027] Step 1: Preparation and detection of standard solution: 5 parts of HAN with different masses, 5 parts of hydroxyethylhydrazine nitrate with different masses, and 5 parts of internal standard aminoguanidine hydrochloride were placed in 100mL volumetric flasks respectively, diluted to the scale with solvent water and shaken well to prepare 5 parts of standard solutions with different concentrations. The masses of each component of the series of standard solutions are shown in Table 1.

[0028] Table 1 Preparation of series of standard solutions in Example 1

[0029]

[0030] Set the capillary electrophoresis conditions, draw a series of standard solutions for injection, and the specific capillary electrophoresis conditions are: the total length of the quartz capillary is 60.2 cm, and the column inner diameter is 75 μm. The capillary electrophoresis used in the present invention uses a voltage of 30 kV. The capillary electrophoresis described in the present invention uses pressure injection, the injection pressure range is 0.5 psi, and the injection time is 5 seconds. The detection wavelength used is ultraviolet, preferably 200 nm. The buffer is a 10-004690 model cationic reagent kit of Beijing Bosiya Biochemical Technology Research Institute.

[0031] Step 2: Draw the standard curve by internal standard method: record the peak area of ​​each substance in the standard solution, and use the ratio of the peak area of ​​HAN and hydroxyethylhydrazine nitrate to the peak area of ​​the internal standard as the horizontal coordinate, and the ratio of the concentration of HAN and hydroxyethylhydrazine nitrate to the concentration of the internal standard as the vertical coordinate to draw the standard curve of HAN and hydroxyethylhydrazine nitrate, where the standard curve of HAN is: y = 0.8039x + 0.0412, R 2 =0.9990; standard curve of hydroxyethylhydrazine nitrate: y=0.7866x-0.0129, R 2 =0.9990.

[0032] Step 3: Preparation and detection of samples to be tested: Accurately weigh 0.1g of non-toxic propellant sample 1# and 0.02g of internal standard aminoguanidine hydrochloride into a 100mL volumetric flask, dilute to the scale with water, shake well, set the capillary electrophoresis conditions (same as step 2) for detection, and the capillary electrophoresis spectrum is attached. Figure 1 .

[0033] Step 4: Calculation of HAN and hydroxyethylhydrazine nitrate contents in the sample to be tested: record the peak areas of HAN, hydroxyethylhydrazine nitrate and internal standard aminoguanidine hydrochloride in the sample, calculate the ratio of the peak areas of HAN and hydroxyethylhydrazine nitrate to the peak area of ​​internal standard aminoguanidine hydrochloride, and obtain the contents of HAN and hydroxyethylhydrazine nitrate through the standard curves of HAN and hydroxyethylhydrazine nitrate.

[0034] According to the method of the present invention, the sample was measured repeatedly for 5 times, and the results of the HAN content in the propellant were respectively 17.10%, 17.40%, 17.32%, 17.44%, and 17.61%, and the relative standard deviation RSD was 1.07%. The results of the hydroxyethylhydrazine nitrate content in the propellant were respectively 13.12%, 12.97%, 13.10%, 12.85%, and 12.97%, and the relative standard deviation RSD was 0.85%, indicating that the results have good repeatability.

[0035] The accuracy of the method was verified by measuring the recovery rate of the spiked sample. The sample solution whose concentration had been determined according to the above steps was taken, and a certain mass of HAN and hydroxyethylhydrazine nitrate standard solution were added respectively, and then capillary electrophoresis analysis was performed according to the above steps three and four to calculate the recovery rate. The results are shown in Table 2. It can be seen from the table that the spiked recovery rate of HAN is 99.1%, and the spiked recovery rate of hydroxyethylhydrazine nitrate is 102.3%, indicating that the accuracy of the method is high and can meet the requirements of quantitative analysis.

[0036] Table 2 Example 1 spike recovery

[0037]

[0038] Example 2

[0039] The determination of the contents of HAN and hydroxyethylhydrazine nitrate in the non-toxic propellant sample 1# comprises the following steps:

[0040] Step 1: Preparation and detection of standard solution: 5 parts of HAN with different masses, 5 parts of hydroxyethylhydrazine nitrate with different masses, and 5 parts of internal standard aminoguanidine nitrate were placed in 100mL volumetric flasks respectively, diluted to the scale with solvent water and shaken well to prepare 5 parts of standard solutions with different concentrations. The masses of each component of the series of standard solutions are shown in Table 3.

[0041] Table 3 Preparation of series of standard solutions in Example 2

[0042]

[0043] Set the capillary electrophoresis conditions, draw a series of standard solutions for injection, and the specific capillary electrophoresis conditions are: the total length range of the quartz capillary is 60.2 cm, and the inner diameter range of the column is 75 μm. The capillary electrophoresis used in the present invention uses a voltage of 35 kV. The capillary electrophoresis described in the present invention adopts pressure injection, the injection pressure range is 0.6 psi, and the injection time is 7 seconds. The detection wavelength used is ultraviolet, preferably 200 nm. The buffer solution is the 10-004690 model cationic kit of Beijing Bosiya Biochemical Technology Research Institute. Step 2: Draw a standard curve by internal standard method: record the peak area of ​​each substance in the standard solution, and use the ratio of the peak area of ​​HAN and hydroxyethylhydrazine nitrate to the peak area of ​​the internal standard as the horizontal coordinate, and the ratio of the concentration of HAN and hydroxyethylhydrazine nitrate to the concentration of the internal standard as the vertical coordinate, and draw the standard curve of HAN and hydroxyethylhydrazine nitrate, wherein the standard curve of HAN: y = 0.7985x + 0.0485, R 2 =0.9987; Standard curve of hydroxyethylhydrazine nitrate: y=0.7906x-0.042, R 2 =0.9984.

[0044] Step 3: Preparation and detection of samples to be tested: Accurately weigh 0.1 g of non-toxic propellant sample 1# and 0.02 g of internal standard aminoguanidine nitrate and place them in a 100 mL volumetric flask, dilute to the scale with water, shake well, and set the capillary electrophoresis conditions (same as step 2) for detection.

[0045] Step 4: Calculation of HAN and hydroxyethylhydrazine nitrate contents in the sample to be tested: record the peak areas of HAN, hydroxyethylhydrazine nitrate and internal standard aminoguanidine nitrate in the sample, calculate the ratio of the peak areas of HAN and hydroxyethylhydrazine nitrate to the peak area of ​​internal standard aminoguanidine nitrate, and obtain the contents of HAN and hydroxyethylhydrazine nitrate through the standard curves of HAN and hydroxyethylhydrazine nitrate.

[0046] According to the method of the present invention, the sample was measured repeatedly for 5 times, and the results of the HAN content in the propellant were respectively 10.34%, 10.45%, 10.65%, 10.40%, and 10.61%, and the relative standard deviation RSD was 1.28%. The results of the hydroxyethylhydrazine nitrate content in the propellant were respectively 15.12%, 14.98%, 14.88%, 14.85%, and 14.97%, and the relative standard deviation RSD was 0.71%, indicating that the results have good repeatability.

[0047] The accuracy of the method was verified by measuring the recovery rate of the spiked sample. The sample solution whose concentration had been determined according to the above steps was taken, and a certain mass of HAN and hydroxyethylhydrazine nitrate standard solution were added respectively, and then capillary electrophoresis analysis was performed according to the above steps three and four to calculate the recovery rate. The results are shown in Table 4. It can be seen from the table that the recovery rate of HAN is 101.9%, and the recovery rate of hydroxyethylhydrazine nitrate is 98.9%, indicating that the accuracy of the method is high and can meet the requirements of quantitative analysis.

[0048] Table 4 Example 2 spike recovery

[0049]

Claims

1. A method for determining the contents of HAN and hydroxyethylhydrazine nitrate in hydroxylamine nitrate-based propellants, characterized in that: The determination method comprises the following steps: Step 1: Preparation and detection of standard solution: Place more than 5 different masses of HAN (hydroxylamine nitrate), more than 5 different masses of hydroxyethylhydrazine nitrate, and internal standard in more than 5 volumetric flasks, dilute to the scale with solvent and shake well, and prepare more than 5 parts of HAN and hydroxyethylhydrazine nitrate series standard solutions of different concentrations, and take the series of standard solutions for capillary electrophoresis detection; Step 2: Draw a standard curve by the internal standard method, record the peak area of ​​each substance (HAN, hydroxyethyl hydrazine nitrate, internal standard) in the standard solution, use the ratio of the HAN peak area to the internal standard peak area, the ratio of the hydroxyethyl hydrazine nitrate peak area to the internal standard peak area as the abscissa or ordinate, use the ratio of the HAN concentration to the internal standard concentration, the ratio of the hydroxyethyl hydrazine nitrate concentration to the internal standard concentration as the ordinate or abscissa, respectively, and draw the standard curves of HAN and hydroxyethyl hydrazine nitrate respectively; Step 3: Preparation and detection of the sample to be tested (hydroxylamine nitrate-based propellant): Accurately weigh the sample and internal standard in a volumetric flask, dilute to the scale with solvent, shake well and perform capillary electrophoresis detection; Step 4: Calculation of HAN and hydroxyethylhydrazine nitrate contents in the sample to be tested: record the peak areas of HAN, hydroxyethylhydrazine nitrate and internal standard in the sample, calculate the ratio of the HAN peak area to the internal standard peak area, the ratio of the hydroxyethylhydrazine nitrate peak area to the internal standard peak area, and obtain the contents of HAN and hydroxyethylhydrazine nitrate through the standard curves of HAN and hydroxyethylhydrazine nitrate respectively; Wherein, the internal standard substance is an aminoguanidine salt compound.

2. The assay method according to claim 1, characterized in that: The internal standard aminoguanidine salt compound is mainly one or more of aminoguanidine hydrochloride and aminoguanidine nitrate.

3. The measuring method according to claim 1, characterized in that: In the capillary electrophoresis conditions, the total length of the quartz capillary used is in the range of 40-100 cm, and the inner diameter of the column is in the range of 50-100 μm; Preferably, the total length of the quartz capillary used is in the range of 40-80 cm, and the inner diameter of the column is in the range of 65-85 μm; Most preferably, the quartz capillary used has a total length in the range of 60.2 cm and a column inner diameter in the range of 75 μm.

4. The assay method according to claim 1 or 3, characterized in that: In the capillary electrophoresis conditions, the capillary electrophoresis voltage used is 15-45 kV; Preferably, the capillary electrophoresis voltage used is 20-40 kV; Most preferably, the capillary electrophoresis voltage used is 30 KV.

5. The assay method according to claim 1, wherein: In the capillary electrophoresis conditions, the capillary electrophoresis adopts pressure injection, the injection pressure range is 0.1-1.0 psi, and the injection time is 1-10 seconds; Preferably, the capillary electrophoresis injection pressure used is in the range of 0.3-0.7 psi, and the injection time is 3-7 seconds; Most preferably, the capillary electrophoresis injection pressure range used is 0.5 psi and the injection time is 5 seconds.

6. The assay method according to claim 1, characterized in that: In the capillary electrophoresis conditions, the detection wavelength used is ultraviolet 180-220nm; Preferably, the capillary electrophoresis detection wavelength used is ultraviolet, preferably 200 nm.

7. The assay method according to claim 1, characterized in that: In the capillary electrophoresis conditions, the capillary electrophoresis buffer used is a commercially available cationic kit; Preferably, the capillary electrophoresis buffer used is a cationic kit from Bosiya.

8. The assay method according to claim 1, characterized in that: In the capillary electrophoresis conditions, The total length of the quartz capillary used is in the range of 40-100 cm, and the inner diameter of the column is in the range of 50-100 μm; the voltage used for the capillary electrophoresis is 15-45 kV; the capillary electrophoresis adopts pressure injection, the injection pressure range is 0.1-1.0 psi, and the injection time is 1-10 seconds; the detection wavelength used is 180-220 nm; the buffer is a commercially available cationic test kit; Preferably, the total length of the quartz capillary used is in the range of 40-80 cm, the inner diameter of the column is in the range of 65-85 μm; the voltage used for capillary electrophoresis is 20-40 kV; the capillary electrophoresis adopts pressure injection, the injection pressure range is 0.3-0.7 psi, and the injection time is 3-7 seconds; the detection wavelength used is ultraviolet, preferably 200 nm. The buffer is a commercially available cationic kit; Most preferably, the total length of the quartz capillary used in the present invention is in the range of 60.2 cm, and the inner diameter of the column is in the range of 75 μm; the voltage used for capillary electrophoresis is 30 kV; the capillary electrophoresis adopts pressure injection, the injection pressure range is 0.5 psi, and the injection time is 5 seconds; the detection wavelength used is ultraviolet, preferably 200 nm; the buffer solution is the cationic reagent kit of Bosiya Company.

Images