Method for determining the content of HAN and hydroxylammonium nitrate in hydroxylammonium nitrate-based propellants

Abstract

The application provides a capillary electrophoresis detection method for a hydroxylamine nitrate-based propellant, and particularly provides a capillary electrophoresis internal standard method for determining the content of HAN and hydroxyl ethyl hydrazine in a non-toxic propellant; the internal standard used is an aminoguanidine salt compound; the separation condition of capillary electrophoresis is that the total length of a quartz capillary ranges from 40 cm to 100 cm, and the inner diameter of the column ranges from 50 mu m to 100 mu m; the voltage used in the capillary electrophoresis is 15 kV to 45 kV; the capillary electrophoresis adopts pressure sampling, the sampling pressure ranges from 0.1 psi to 1.0 psi, and the sampling time is 1 second to 10 seconds; and the detection wavelength used is ultraviolet 180 nm to 220 nm; and the buffer is a commercially available cation kit.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of propellant detection, more particularly, to a method for determining the content of HAN and hydroxyl ethyl hydrazine in non-toxic propellant. BACKGROUND

[0002] Liquid unit propellant is widely used in space vehicles such as rockets, satellites, spaceships, etc. for attitude and orbit control, and in the field of aircraft emergency power. The most widely used liquid unit propellant, such as hydrazine, has the disadvantages of high toxicity and environmental pollution. With the improvement of people's environmental awareness and the urgent need for high-performance propulsion technology, the development of non-toxic, non-polluting, environmentally friendly green new propellant is the main direction of the development of advanced space power. New single-component propellants are usually compounded by 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 AF-315 series single-component propellants, mainly composed of HAN, hydroxyl ethyl hydrazine (hydroxyl ethyl hydrazine nitrate (β-HEHN)) and water. Among them, the specific impulse and density impulse of AF-315E propellant are 11% and 70% higher than those of hydrazine single-component propellant, respectively.

[0003] It has become one of the most attractive alternatives. Domestic units such as Dalian Institute of Chemical Physics have been engaged in green single-component propellant research since 2000 and have developed a series of HAN-based propellants, with the HAN / hydroxyl ethyl hydrazine / water system being one of them.

[0004] The stability of the propellant formula has an important influence on its application performance, energy and combustion temperature. Therefore, establishing an analysis method for the content of hydroxylamine nitrate and hydroxyl ethyl hydrazine in the propellant system has a key influence on the stability control of the propellant during the design and development of the propellant formula, and is of great significance to the development of green new propellant research. However, there is no reported method for detecting HAN and hydroxyl ethyl hydrazine in HAN-based propellants, so there is an urgent need to develop a simple and rapid detection method with high accuracy and precision. SUMMARY

[0005] In order to solve the existing technical problems, the present application provides a method for detecting the content of HAN and hydroxyl ethyl hydrazine in non-toxic propellant, which is fast, simple and accurate. The method solves the problem of inaccurate determination of the content of HAN and hydroxyl ethyl hydrazine caused by the difficulty in accurately controlling the injection amount of the external standard method.

[0006] The present application provides a method for determining the content of HAN and hydroxyl ethyl hydrazine in non-toxic propellant, which comprises the following steps:

[0007] Step one: preparation of standard solution and detection: more than 5 different quality of HAN, more than 5 different quality of hydroxyl hydrazine nitrate, internal standard were placed in more than 5 volumetric flask, diluted to the mark with solvent, then shaken to prepare more than 5 different concentration series of HAN and hydroxyl hydrazine nitrate standard solution, and then the series of standard solution was taken for capillary electrophoresis detection;

[0008] Step two: internal standard method was used to draw standard curve, the peak area of each substance (HAN, hydroxyl hydrazine nitrate, internal standard) in the standard solution was recorded, the ratio of HAN peak area to internal standard peak area and the ratio of hydroxyl hydrazine nitrate peak area to internal standard peak area were taken as the horizontal coordinate or vertical coordinate, and the ratio of HAN concentration to internal standard concentration and the ratio of hydroxyl hydrazine nitrate concentration to internal standard concentration were taken as the vertical coordinate or horizontal coordinate, respectively, to draw the standard curve of HAN and hydroxyl hydrazine nitrate;

[0009] Step three: preparation and detection of the sample (non-toxic propellant) to be tested: the sample and internal standard were accurately weighed in a volumetric flask, diluted to the mark with solvent, then shaken and subjected to capillary electrophoresis detection;

[0010] Step four: calculation of the content of HAN and hydroxyl hydrazine nitrate in the sample to be tested: the peak area of HAN, hydroxyl hydrazine nitrate and internal standard in the sample was recorded, the ratio of HAN peak area to internal standard peak area and the ratio of hydroxyl hydrazine nitrate peak area to internal standard peak area were calculated, and the content of HAN and hydroxyl hydrazine nitrate was obtained through the standard curve of HAN and hydroxyl hydrazine nitrate, respectively;

[0011] Preferably, the internal standard is mainly amino guanidine hydrochloride and amino guanidine nitrate.

[0012] Further, in the capillary electrophoresis conditions, the total length of the quartz capillary used in the application ranges from 40 to 100 cm, and the column inner diameter ranges from 50 to 100 μm. Preferably, the total length of the quartz capillary ranges from 40 to 80 cm, and the column inner diameter ranges from 65 to 85 μm. More preferably, the total length of the quartz capillary ranges from 60.2 cm, and the column inner diameter ranges from 75 μm.

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

[0014] Further, in the capillary electrophoresis conditions, the capillary electrophoresis of the present application uses 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 range is 0.3-0.7 psi, and the injection time is 3-7 seconds. More preferably, the capillary electrophoresis injection pressure range is 0.5 psi, and the injection time is 5 seconds.

[0015] Further, in the capillary electrophoresis conditions, the detection wavelength used in the present application is ultraviolet 180-220 nm. Preferably, the capillary electrophoresis detection wavelength is ultraviolet, preferably 200 nm.

[0016] Further, in the capillary electrophoresis conditions, the capillary electrophoresis buffer used in the present application is a commercially available cationic kit. Preferably, the capillary electrophoresis buffer is a cationic kit of Bio-Rad Company.

[0017] As preferred, in the capillary electrophoresis conditions of the present application, the total length of the quartz capillary ranges from 40-100 cm, and the column inner diameter ranges from 50-100 μm. The capillary electrophoresis used in the present application uses a voltage of 15-45 kV. The capillary electrophoresis of the present application uses 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 kit.

[0018] Further, in the preferred capillary electrophoresis conditions, the total length of the quartz capillary used in the present application ranges from 40-80 cm, and the column inner diameter ranges from 65-85 μm. The capillary electrophoresis used in the present application uses a voltage of 20-40 kV. The capillary electrophoresis of the present application uses 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.

[0019] More preferably, in the capillary electrophoresis conditions, the total length of the quartz capillary used in the present application is 60.2 cm, and the column inner diameter is 75 μm. The capillary electrophoresis used in the present application uses a voltage of 30 kV. The capillary electrophoresis of the present application 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 cationic kit of Bio-Rad Company.

[0020] Further, the configuration and detection of the standard solution and the configuration and detection of the sample to be tested are as follows:

[0021] (0-60) mg of HAN, 5 different masses (0-60) mg of hydroxyl ethyl hydrazine nitrate were weighed in 5 100 mL volumetric flasks in order of increasing or decreasing mass, respectively, and (10-60) mg (preferably (20-30) mg) of the internal standard aminoguanidine hydrochloride was added to the volumetric flask, diluted to the mark with water, mixed well, and after preparation of 5 different concentration gradient series standard solutions, detection was performed.

[0022] Sample solution preparation and detection: (0.05-0.15) g of sample and (10-60) mg (preferably (20-30) mg) of the internal standard aminoguanidine hydrochloride were accurately weighed into a 100 mL volumetric flask, diluted to the mark with water, mixed well, and detection was performed after mixing.

[0023] The method is simple, reproducible, accurate, and efficiently determines the content of HAN and hydroxyl ethyl hydrazine nitrate in non-toxic propellants, and has important significance for the detection of non-toxic propellants. BRIEF DESCRIPTION OF DRAWINGS

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

[0025] Example 1

[0026] The determination of the content of HAN and hydroxyl ethyl hydrazine nitrate in non-toxic propellant sample 1# includes the following steps:

[0027] Step one: preparation and detection of standard solution: 5 different masses of HAN, 5 different masses of hydroxyl ethyl hydrazine nitrate, and 5 internal standards aminoguanidine hydrochloride were respectively placed in 100 mL volumetric flasks, diluted to the mark with solvent water, mixed well, and 5 different concentration standard solutions were prepared, and the mass of each component of the series standard solution is shown in Table 1.

[0028] Table 1 Preparation of series standard solution of Example 1

[0029]

[0030] The capillary electrophoresis conditions were set, and the series standard solution was taken for sampling, and the specific capillary electrophoresis conditions were: the total length of the quartz capillary was 60.2 cm, and the inner diameter of the column was 75 μm. The voltage used in the capillary electrophoresis of the application was 30 kV. The capillary electrophoresis described in the application used pressure sampling, the sampling pressure was 0.5 psi, and the sampling time was 5 seconds. The detection wavelength used was ultraviolet, preferably 200 nm. The buffer described is a 10-004690 type cation reagent kit from Beijing Bosiya Biochemical Technology Research Institute.

[0031] Step two: draw standard curve by internal standard method: record the peak area of each substance in standard solution, take the ratio of HAN, hydroxylammonium nitrate peak area to internal standard peak area as the abscissa, and take the ratio of HAN, hydroxylammonium nitrate concentration to internal standard concentration as the ordinate, draw the standard curve of HAN, hydroxylammonium nitrate, wherein the standard curve of HAN: y = 0.8039x + 0.0412, R 2 = 0.9990; the standard curve of hydroxylammonium nitrate: y = 0.7866x - 0.0129, R 2 = 0.9990.

[0032] Step three: configuration and detection of the sample to be tested: accurately take 0.1 g of non-toxic propellant sample 1# and 0.02 g of internal standard aminoguanidine hydrochloride into a 100 mL volumetric flask, dilute to the mark with water, shake well, and then set the capillary electrophoresis conditions (synchronous step two) for detection. The capillary electrophoresis spectrum is shown in Figure 2. Figure 1 .

[0033] Step four: calculation of the content of HAN and hydroxylammonium nitrate in the sample to be tested: record the peak area of HAN, hydroxylammonium nitrate and internal standard aminoguanidine hydrochloride in the sample, calculate the ratio of the peak area of HAN, hydroxylammonium nitrate to the peak area of internal standard aminoguanidine hydrochloride, and obtain the content of HAN and hydroxylammonium nitrate by the standard curve of HAN and hydroxylammonium nitrate.

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

[0035] The accuracy of the method was verified by measuring the standard addition recovery rate of the sample. The sample solution with a certain concentration was measured according to the above steps, and then a certain amount of HAN and hydroxylammonium nitrate standard solution was added, and then capillary electrophoresis analysis was carried out according to the above steps three and four, and the recovery rate was calculated. The results are shown in Table 2. It can be seen from the table that the standard addition recovery rate of HAN is 99.1%, and the standard addition recovery rate of hydroxylammonium nitrate is 102.3%, indicating that the accuracy of the method is high and can meet the requirements of quantitative analysis.

[0036] Table 2 standard addition recovery rate of example 1

[0037]

[0038] Example 2

[0039] Determination of HAN and hydroxyl-ethyl hydrazine content in non-toxic propellant sample 1#, comprising the following steps:

[0040] Step one: preparation and detection of standard solution: 5 different masses of HAN, 5 different masses of hydroxyl-ethyl hydrazine, and 5 different masses of internal standard amino guanidine nitrate were respectively placed in 100 mL volumetric flasks, diluted to the mark with solvent water, and then shaken to prepare 5 different concentrations of standard solutions. The mass of each component of the series of standard solutions is shown in Table 3.

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

[0042]

[0043] Capillary electrophoresis conditions were set, and the series of standard solutions were sampled. The specific capillary electrophoresis conditions were as follows: the total length of the quartz capillary was 60.2 cm, and the inner diameter of the column was 75 μm. The voltage used in the capillary electrophoresis was 35 kV. The capillary electrophoresis described herein used pressure sampling, the sampling pressure was 0.6 psi, and the sampling time was 7 seconds. The detection wavelength used was ultraviolet, preferably 200 nm. The buffer used was a cation reagent kit of model 10-004690 from Beijing Bosiya Biochemical Technology Research Institute. Step two: drawing a standard curve by internal standard method: the peak areas of each substance in the standard solution were recorded, the ratio of the peak area of HAN and hydroxyl-ethyl hydrazine to the peak area of the internal standard was taken as the abscissa, and the ratio of the concentration of HAN and hydroxyl-ethyl hydrazine to the concentration of the internal standard was taken as the ordinate, to draw the standard curve of HAN and hydroxyl-ethyl hydrazine, wherein the standard curve of HAN: y = 0.7985x + 0.0485, R 2 = 0.9987; and the standard curve of hydroxyl-ethyl hydrazine: y = 0.7906x - 0.042, R 2 = 0.9984.

[0044] Step three: preparation and detection of the sample to be tested: 0.1 g of non-toxic propellant sample 1# and 0.02 g of internal standard amino guanidine nitrate were accurately weighed and placed in a 100 mL volumetric flask, diluted to the mark with water, and then shaken to set the capillary electrophoresis conditions (as in step two) for detection.

[0045] Step four: calculation of the content of HAN and hydroxyl-ethyl hydrazine in the sample to be tested: the peak areas of HAN, hydroxyl-ethyl hydrazine, and internal standard amino guanidine nitrate in the sample were recorded, the ratio of the peak area of HAN and hydroxyl-ethyl hydrazine to the peak area of the internal standard amino guanidine nitrate was calculated, and the content of HAN and hydroxyl-ethyl hydrazine was obtained by the standard curve of HAN and hydroxyl-ethyl hydrazine.

[0046] The sample was determined for 5 times repeatedly according to the method of the present application, the content of HAN in propellant was 10.34%, 10.45%, 10.65%, 10.40%, 10.61% respectively, the relative standard deviation RSD was 1.28%, the content of hydroxyl-ethyl hydrazine in propellant was 15.12%, 14.98%, 14.88%, 14.85%, 14.97% respectively, the relative standard deviation RSD was 0.71%, which showed that the repeatability of the results was good.

[0047] The accuracy of the method was verified by determining the recovery of the sample, the sample solution with determined concentration was taken, a certain mass of HAN and hydroxyl-ethyl hydrazine standard solution was added respectively, then capillary electrophoresis analysis was carried out according to the above steps 3 and 4, the recovery was calculated, the results were shown in Table 4, it could be seen from the table that the recovery of HAN was 101.9%, the recovery of hydroxyl-ethyl hydrazine was 98.9%, which showed that the accuracy of the method was high, and the method could meet the requirements of quantitative analysis.

[0048] Table 4 recovery of example 2

[0049]

Claims

1. A method for determining the content of HAN and hydroxyl ethyl hydrazine in hydroxylammonium nitrate-based propellants, characterized in that, The determination method comprises the following steps: Step 1: Preparation and detection of standard solution: more than 5 different mass of HAN, more than 5 different mass of hydroxyl ethyl hydrazine, and an internal standard are respectively placed in more than 5 volumetric flasks, diluted to the scale with a solvent, and then shaken to prepare more than 5 different concentration series of HAN and hydroxyl ethyl hydrazine standard solutions, and the series of standard solutions are taken for capillary electrophoresis detection; Step 2: Drawing a standard curve by internal standard method, recording the peak area of HAN, hydroxyl ethyl hydrazine and the internal standard in the standard solution, taking the ratio of the peak area of HAN to the peak area of the internal standard and the ratio of the peak area of hydroxyl ethyl hydrazine to the peak area of the internal standard as the horizontal coordinate or the vertical coordinate, and taking the ratio of the concentration of HAN to the concentration of the internal standard and the ratio of the concentration of hydroxyl ethyl hydrazine to the concentration of the internal standard as the vertical coordinate or the horizontal coordinate, respectively, to draw the standard curves of HAN and hydroxyl ethyl hydrazine; Step 3: Preparation and detection of the sample to be tested: the sample and the internal standard are accurately weighed in a volumetric flask, diluted to the scale with a solvent, and then shaken and subjected to capillary electrophoresis detection; Step 4: Calculation of the content of HAN and hydroxyl ethyl hydrazine in the sample to be tested: the peak area of HAN, hydroxyl ethyl hydrazine and the internal standard in the sample is recorded, the ratio of the peak area of HAN to the peak area of the internal standard and the ratio of the peak area of hydroxyl ethyl hydrazine to the peak area of the internal standard are calculated, and the content of HAN and hydroxyl ethyl hydrazine is obtained through the standard curves of HAN and hydroxyl ethyl hydrazine respectively. The internal standard is an aminoguanidine salt compound.

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

3. The assay method of claim 1, wherein: In the capillary electrophoresis detection, the total length of the quartz capillary used ranges from 40-100 cm, and the column inner diameter ranges from 50-100 μm.

4. The assay method according to claim 3, characterized in that: The total length of the quartz capillary used ranges from 40-80 cm, and the column inner diameter ranges from 65-85 μm.

5. The assay method according to claim 1 or 3, characterized by: In the capillary electrophoresis detection, the voltage used in the capillary electrophoresis is 15-45 kV.

6. Assay according to claim 5, characterized in that: The voltage used in the capillary electrophoresis is 20-40 kV.

7. The assay method of claim 1, wherein: In the capillary electrophoresis detection, the capillary electrophoresis detection adopts pressure sampling, the sampling pressure ranges from 0.1-1.0 psi, and the sampling time is 1-10 seconds.

8. The assay method according to claim 7, characterized in that: The sampling pressure used in the capillary electrophoresis detection ranges from 0.3-0.7 psi, and the sampling time is 3-7 seconds.

9. The assay method of claim 1, wherein: In the capillary electrophoresis detection, the detection wavelength used is ultraviolet 180-220 nm.

10. The assay method of claim 1, wherein: In the capillary electrophoresis detection, the capillary electrophoresis buffer used is a commercially available cation kit.

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