GB 18059-2000 Hygienic standard for unsymmetrical dimethylhydrazine in the atmosphere of residential areas
Some standard content:
GB18059—2000
All technical contents of this standard are mandatory. Fore
In order to implement the "Environmental Protection Law of the People's Republic of China" and the "Law of the People's Republic of China on the Prevention and Control of Air Pollution", prevent and control the pollution of the residential environment by the waste gas generated by aerospace industrial enterprises, and protect the health of the general public. According to the principles of formulating residential air hygiene standards, refer to foreign research results, and formulate this standard based on the actual situation in my country. This standard shall be implemented on January 1, 2001. Appendix A and Appendix B of this standard are both appendices to the standard. This standard was proposed by the Ministry of Health of the People's Republic of China and the Ministry of Aerospace Industry. The responsible drafting unit of this standard is the Seventh Design Institute of the Ministry of Aerospace Industry; participating drafting units are: Shanghai Medical University, 101 Institute of the Ministry of Aerospace Industry.
The main drafters of this standard are: Wang Xinchao, Yang Youming, and Zhu Mingsheng. This standard is entrusted by the Ministry of Health to the Institute of Environmental Health Monitoring of the Chinese Academy of Preventive Medicine for interpretation. 52
National Standard of the People's Republic of China
Hygienic standard for unsymmetric dimethylhydrazine in air of residential area
GB 18059-2000
This standard specifies the maximum permissible concentration of unsymmetric dimethylhydrazine in air of residential area and its monitoring and inspection methods. This standard is applicable to the monitoring and evaluation of the atmospheric environment in residential areas. 2 Contents of the standard
2.1 The hygienic standard values of unsymmetric dimethylhydrazine in air of residential area are as follows: daily average maximum permissible concentration: 0.03mg/m2; single maximum permissible concentration: 0.08mg/m2. 2.2 Monitoring and inspection methods
The monitoring and inspection methods of this standard are shown in Appendix A and Appendix B. Approved by the State Administration of Quality and Technical Supervision on April 10, 2000, and implemented from January 2001 to January 2001
A1 Principle
GB 18059—2000
Appendix A
(Appendix to the standard)
Monitoring and testing method of unsymmetrical dimethylhydrazine in air Solid adsorption/spectrophotometric method Trace unsymmetrical dimethylhydrazine in air is concentrated by solid adsorbent coated with sulfuric acid, desorbed by buffer solution, and reacted with amino sodium ferrocyanide (TPF) under weak acidic conditions to form a red complex. Within the measurement range, the color depth is proportional to the unsymmetrical dimethylhydrazine content, which conforms to the Lambert-Beer law. The maximum absorption wavelength of the red complex is 500nm. Ammonia, nitrogen dioxide, sulfur dioxide, hydrogen sulfide, and chlorine in the air have no interference with this method. When the concentration of unsymmetrical dimethylhydrazine is lower than 0.3mg/m2 and the concentration of methylhydrazine is lower than 0.5mg/m2, there is basically no interference with the determination of unsymmetrical dimethylhydrazine. Determination range: 0.027～5.46mg/m2. When it is greater than 5.46mg/m2, it can be diluted and measured. When the total sampling volume is 120L, the minimum detection concentration is: 0.015mg/m. A2 Reagents or materials
A2.1 Sulfuric acid: high-grade pure.
Methanol: high-grade pure.
Anhydrous ethanol: analytical grade.
A2.4 Ether: analytical grade.
A2.5 Concentrated ammonia water: analytical grade.
Unsymmetrical dimethylhydrazine: purity above 98%.
Citric acid (CHO, ·H,O): analytical grade. Disodium hydrogen phosphate (Naz2HPO4·12H,O): analytical grade. A2.8
Sodium nitrosoferrocyanide.
06201 Carrier: 40～60 mesh.
A2.11 Sulfuric acid 6mol/L, c (H, SO.): slowly inject 33.3mL concentrated sulfuric acid into 50mL distilled water, then accurately dilute to 100 mL with distilled water, and shake to hook.
A2.12 Sulfuric acid-methanol solution: add 200mL methanol to a 250mL volumetric flask, slowly inject 36mL sulfuric acid (A2.11), dilute to the mark with methanol, and shake to hook.
Instruments or equipment
A3.1 Stoppered graduated tube: 25mL, 20 pieces. A3.2
Graduated pipette: 1mL, 2 pieces; 2mL, 2 pieces; 5mI, 2 pieces; 10mL, 2 pieces.
Syringe: 1mL, 1 piece.
A3.4 Micro syringe: 10μL, 1 piece; 50μL, 1 piece. A3.5 Spectrophotometer.
A3.6 Acidity meter.
Empty box barometer.
A3.8 Atmospheric sampler.
A3.9 Sampling sieve.
Sampling tube, process according to Figure A1.
A4 Sampling
GB 18059.--2000
Select the sampling point, install the sampler, and adjust the height to about 1.5m from the ground. Connect the sampling tube, make the tube mouth downward, adjust the timer, and sample 180L at a flow rate of 3I/min. The factory area can sample 30~100I. At the same time, record the ambient temperature, atmospheric pressure, wind direction, wind speed, etc. When taking parallel samples, tie the two sampling tubes together. After sampling, remove the sampling tube, seal the two ends of the tube with polyethylene caps, put it in a black paper bag, and send it to the laboratory for analysis. The sampling tube can be stored for two weeks at room temperature. A5 Analysis steps
A5.1 Preparation of buffer solution
A5.1.1 0.1 mol/L citric acid: Weigh 21.0 g citric acid and dissolve it in 500 ml distilled water, transfer to a 1000 ml volumetric flask, dilute to the mark with distilled water, and shake.
A5.1.2 0.2 mol/l disodium hydrogen phosphate: Weigh 71.6 g disodium hydrogen phosphate and dissolve it in 500 ml distilled water, transfer to a 1000 ml volumetric flask, dilute to the mark with distilled water, and shake. A5.1.3 Preparation of buffer solution: Use the above two solutions to prepare pH 5.4 and pH 6.2 buffer solutions in proportion, see Table (A1). Table A1
Solution pH
0.1 mol/L citric acid, mL
A5.2 Preparation of sodium aminoferrocyanide (TPF) 0.2 mol/L disodium phosphate, ml
Weigh 10.0 g of sodium nitrosoferrocyanide, grind it into a conical flask, add 32 mL of concentrated ammonia water, shake it and cover it, let it stand at 0°C for 12 hours, add 20 mL of anhydrous ethanol to obtain a yellow precipitate, filter it with a Buchner funnel, first rinse it with 60 ml of anhydrous ethanol and then with ether three times, and drain it. Move the yellow solid to surface III, place it in a desiccator for more than 2 hours, then transfer it to a brown narrow-necked bottle and store it in a dark place. A5.3 0.2% TPF color developer
Weigh 0.10g TPF powder and dissolve it in 25mL distilled water, transfer it into a 50ml brown volumetric flask, dilute it to the mark with distilled water, and shake it well. Prepare it on the day of the experiment.
A5.4 Preparation of solid adsorbent and sampling tube Weigh 5.0g 6201 support, boil it in 100mL distilled water for 2min, rinse it with distilled water 5 times, 100ml of water each time, visually inspect the clarity of the upper clear liquid and the distilled water as the blank, take the upper clear liquid and use the distilled water as the blank, measure the absorbance at 500nm with a 2cm colorimetric dish, and it is qualified if it is not greater than 0.02.
Drain the washed support with a Buchner funnel, transfer it to a watch glass, dry it at 70℃ for 40min, move it to a dryer, and cool it to room temperature. Weigh 4.0g of the clean support, spread it evenly on the surface blood, and drop 11.00ml of sulfuric acid-methanol solution to make it evenly soaked. Place it in a fume hood to air dry, and then dry it at 60℃±1℃ for 40~~50min until it is loose and not lumpy. Cool it to room temperature in a dryer and bottle it for later use. Weigh 0.30g of the sulfuric acid-coated support and inject it into a special glass sampling tube (Figure A1). Fix the two ends of the support with a clean stainless steel mesh (60), and seal the two ends of the tube with a polyethylene cap.
1-Stainless steel mesh; 2-Sulfur acid-coated support
Figure A1 Glass sampling tube
A5.5 Preparation of standard solution
GB 18059-2000
In a 100ml volumetric flask, add 50mL of pH5.4 buffer solution and 5mL of 6mol/I sulfuric acid and shake well. Use a syringe to weigh 0.1g (accurate to 0.0001g) of unsymmetrical dimethylhydrazine by the reduction method, and inject it into a volumetric flask. When weighing, use a small rubber block to seal the needle tip to prevent leakage of the unsymmetrical dimethylhydrazine. Gently shake the volumetric flask to dissolve the unsymmetrical dimethylhydrazine. After 20 minutes, dilute to the scale with pH5.4 buffer solution and shake to hook. This standard solution can be stored for two weeks at room temperature. A5.6 Drawing of the standard curve
Take 11 stoppered graduated tubes, number them, and add 15mlL of pH6.2 buffer solution and 0.30g of sulfuric acid-coated support respectively. 3 tubes are used as blanks, and the remaining 8 tubes are added with 3, 6, 912.15, 20, 3040L of unsymmetrical dimethylhydrazine standard solution respectively. Then add 1mL of TPF color developer to each of the 11 tubes and use pH6.2. Dilute the buffer solution to the mark, invert each tube 5 times, and then place it in the dark to develop color for 50 minutes (at 20°C). Using distilled water as a reference, use a 2cm colorimetric dish to measure the absorbance of the upper clear liquid at a 0.02mm slit and 500nm, and subtract the blank average absorbance to obtain the net absorbance value of each solution. Draw the mass (μg)-absorbance curve of the unsymmetrical dimethylhydrazine contained in the solution. A5.7 Desorption
Transfer the solid adsorbent and the stainless steel mesh after sampling into a stoppered graduated tube, rinse the sampling tube wall with 20ml of pH6.2 buffer solution 3 times, and finally dilute it to the mark with pH6.2 buffer solution, invert 5 times, and let it stand for 20 minutes. The same steps are used for the 3 blank tubes. A5.8 Colorimetry
Use a graduated pipette to absorb 1mL of the upper clear liquid after desorption and place it in another stoppered graduated tube for standby use. Add 1 ml of TPF color developer to the remaining desorption solution, invert 5 times, and color in the dark for 50 minutes (at 20°C). The dilution factor of this solution is 1.042. Determine the absorbance according to the conditions and steps for making the standard curve. After subtracting the blank average absorbance, find out the mass (μg) of unsymmetrical dimethylhydrazine contained in the solution from the standard curve.
If the color depth exceeds the measurement range, add 15 ml of pH 5.4 buffer solution and 1 ml of TPF color developer to the spare 1 ml sample, dilute to the scale with pH 5.4 buffer, invert 5 times, and determine the absorbance after coloring in the dark. The dilution factor of this solution is 25. A6 Result Calculation
Calculate the concentration of unsymmetrical dimethylhydrazine in the atmosphere according to formula (A1). c= n ×WX1: 013 X10 X(273 ± T)Q × t × Pr × 273
W——-the mass of UDMH contained in the solution, ug; Q-sampling flow, L/min;
tsampling time, min;
Pr——atmospheric pressure at sampling, Pa;
T——ambient temperature at sampling, °C.
A7 Precision or allowable error
. (Al)
When the concentration of UDMH is lower than 0.134mg/m2, the relative standard deviation is not more than 16%; when the concentration is 0.134~5.46mg/m, the relative standard deviation is not more than 5.0%. Notes
1 The pH value of the pH 6.2 buffer solution should be adjusted in advance for each batch of support to ensure that the pH of the tested solution is 5.4 ± 0.2. 1
The ambient temperature affects both the color development time and the color stability. The color development time can be selected according to the table below, or the color development time can be 20 minutes in a 30°C constant temperature water bath. Temperature, c
Time.min
B1 Principle
GB18059—2000
Appendix B
(Appendix of the standard)
Monitoring and testing methods for unsymmetrical dimethyl hydrazine in the atmosphere Solid adsorption/gas chromatography method Use a solid adsorbent coated with sulfuric acid to capture unsymmetrical dimethyl hydrazine in the air, then elute with water, add furfural derivatization reagent, and generate unsymmetrical dimethyl derivatives. Extract with ethyl acetate and analyze with a gas chromatograph. Calculate the content of unsymmetrical dimethyl hydrazine based on the peak height. This method can be determined simultaneously.
Measurement range: unsymmetrical dimethyl hydrazine 0.026-~6.7mz/m; hydrazine 0.00714～1.00mg/m. The upper limit of determination can be extended. The minimum detection concentration of the method: unsymmetrical dimethyl hydrazine is 0.0208mg/m when sampling 120L, and 0. 007 2 mg/m when sampling 60L
B2 Reagents or materials
B2.1 Furfural: analytical grade.
B2.2 Ethyl acetate: analytical grade.
B2.3 Sodium acetate: analytical grade.
B2.4 Sulfuric acid: analytical grade.
B2.5 Sulfuric acid, methanol, 6201 support, unsymmetrical dimethyl hydrazine, sulfuric acid-methanol solution, 6mol/L sulfuric acid are the same as Appendix A. B2.6 0.05mol/L sulfuric acid: Take 8.3mL of 6mol/L sulfuric acid and slowly inject it into 1000mL of distilled water, and shake well. Instruments or equipment
B3.1 Gas chromatograph: with hydrogen flame ionization detector. B3.2 Stoppered test tubes: 5mL, 10 pieces.
B3.3 Micro syringes: 10μL, 2 pieces. B3.4 Atmospheric sampler, empty box barometer, sampling tube, etc. are the same as Appendix A. B4 Sampling
The sampling operation steps and requirements are the same as Appendix A. B5 Analysis steps
B5.1.1 Preparation of furfural derivatization reagent: Pipette 2mL of freshly distilled aldehyde into a 50mL volumetric flask, dilute to the scale with 0.5mol/L sodium acetate solution, and shake well.
B5.1.2 Preparation of solid adsorbent and sampling tube: Prepare solid adsorbent using 6201 carrier. The steps of boiling, rinsing, acid coating and drying are the same as those in Appendix A.
Weigh 0.20 μl of the sulfuric acid-coated support and inject it into a specially prepared glass sampling tube. The two ends of the twisted body are fixed with clean stainless steel mesh. The two ends of the tube are sealed with polyethylene caps.
B5.1.3 Preparation of standard solution
Take unsymmetrical dimethylhydrazine W with a purity of ℃t and inject it into 0.4 mol/L sulfuric acid with a volume of V to prepare a standard solution of unsymmetrical dimethylhydrazine. The concentration of unsymmetrical dimethylhydrazine (A) can be calculated according to formula (B1). 57
GB180592000
（B1)
Bake hydrazine sulfate at 100°C for 2h, weigh W2, dissolve it in 0.4 mol/L sulfuric acid V, and prepare a standard solution of hydrazine. The concentration of hydrazine (B) can be calculated according to the formula (B2):
0. 246C2 X W2
Wherein: 0.246
Conversion coefficient of hydrazine sulfate and hydrazine;
B5.2 Derivation
Purity of hydrazine sulfate.
·(B2)
After sampling, the solid adsorbent is transferred to a stoppered test tube, eluted with 2ml. distilled water, and then 2mL of furfural derivatization reagent is added. The reaction is carried out at room temperature for 60min, and extracted with 1mL of ethyl acetate for 20min. B5.3 Chromatographic conditions
Chromatographic column: 10% OV-7/supelcoport, 80～100 mesh; 4m×3mm glass column. Flow rate: carrier gas (N,), 50mL/min; fuel gas (H2), 70mL/min; auxiliary gas (air), 500mL/min. The above values are all indicated values of the rotor flowmeter.
Temperature: Column temperature 205℃; Vaporization chamber and detection chamber 315℃. Injection volume: 10μL.
Typical chromatographic peak diagram is shown in Figure B1.
Chromatographic peak diagram of Figure B1 under selected conditions
B5.4 Drawing of standard curve
Take 6 stoppered test tubes, add 0.20g of solid adsorbent and 2ml of distilled water respectively, and add a series of standard solutions of unsymmetrical dimethylhydrazine or hydrazine in sequence. Then add 2ml of furfural derivatization reagent to each, react at room temperature for 60min, extract with 1mL of ethyl acetate for 20min, and absorb 10μl. The extract is injected into the chromatograph for analysis. Draw a standard curve with peak height as the ordinate and sample content as the abscissa. B5.5 Sample determination
GB 18059--2000
Take 10% of the sample extract and inject it into the chromatograph for analysis. Measure the peak height of unsymmetrical dimethylhydrazine and hydrazine, and find out the mass of unsymmetrical dimethylhydrazine and hydrazine in the sample (ug) from the standard curve. Mixed samples of unsymmetrical dimethylhydrazine and hydrazine should be analyzed on the same day after sampling. B6 Calculation
Calculate the concentration of dimethylhydrazine and hydrazine in the atmosphere according to (B3) and (B4):
Where: unsymmetrical dimethylhydrazine concentration, ng/n
C hydrazine concentration nmg/m
a-mass of unsymmetrical dimethylhydrazine contained in the sample solution, μg; 6-mass of hydrazine contained in the sample solution, μg
V. Flow rate corrected to standard state, L/mmtSampling time, min.
Precision or allowable error
The average relative error of unsymmetrical dimethylhydrazine is 9.3%; the average relative error of hydrazine is 3.7%. ·(B3)8 Colorimetry
Use a graduated pipette to absorb 1 mL of the upper clear liquid after desorption and place it in another stoppered graduated tube for standby use. Add 1 mL of TPF color developer to the remaining desorption solution, invert 5 times, and color in the dark for 50 minutes (at 20°C). The dilution factor of this solution is 1.042. Determine the absorbance according to the conditions and steps for making the standard curve. After subtracting the blank average absorbance, find out the mass (μg) of unsymmetrical dimethylhydrazine contained in the solution from the standard curve.
If the color depth exceeds the measurement range, add 15 mL of pH 5.4 buffer solution and 1 mL of TPF color developer to the standby 1 mL sample, dilute to the scale with pH 5.4 buffer, invert 5 times, and color in the dark after measuring the absorbance. The dilution factor of this solution is 25. A6 Result calculation
Calculate the concentration of unsymmetrical dimethylhydrazine in the atmosphere according to formula (A1). c= n ×WX1: 013 X10 X(273 ± T)Q × t × Pr × 273
W——-the mass of UDMH contained in the solution, ug; Q-sampling flow, L/min;
tsampling time, min;
Pr——atmospheric pressure at sampling, Pa;
T——ambient temperature at sampling, °C.
A7 Precision or allowable error
. (Al)
When the concentration of UDMH is lower than 0.134mg/m2, the relative standard deviation is not more than 16%; when the concentration is 0.134~5.46mg/m, the relative standard deviation is not more than 5.0%. Notes
1 The pH value of the pH 6.2 buffer solution should be adjusted in advance for each batch of support to ensure that the pH of the tested solution is 5.4 ± 0.2. 1
The ambient temperature affects both the color development time and the color stability. The color development time can be selected according to the table below, or the color development time can be 20 minutes in a 30°C constant temperature water bath. Temperature, c
Time.min
B1 Principle
GB18059—2000
Appendix B
(Appendix of the standard)
Monitoring and testing methods for unsymmetrical dimethyl hydrazine in the atmosphere Solid adsorption/gas chromatography method Use a solid adsorbent coated with sulfuric acid to capture unsymmetrical dimethyl hydrazine in the air, then elute with water, add furfural derivatization reagent, and generate unsymmetrical dimethyl derivatives. Extract with ethyl acetate and analyze with a gas chromatograph. Calculate the content of unsymmetrical dimethyl hydrazine based on the peak height. This method can be determined simultaneously.
Measurement range: unsymmetrical dimethyl hydrazine 0.026-~6.7mz/m; hydrazine 0.00714～1.00mg/m. The upper limit of determination can be extended. The minimum detection concentration of the method: unsymmetrical dimethyl hydrazine is 0.0208mg/m when sampling 120L, and 0. 007 2 mg/m when sampling 60L
B2 Reagents or materials
B2.1 Furfural: analytical grade.
B2.2 Ethyl acetate: analytical grade.
B2.3 Sodium acetate: analytical grade.
B2.4 Sulfuric acid: analytical grade.
B2.5 Sulfuric acid, methanol, 6201 support, unsymmetrical dimethyl hydrazine, sulfuric acid-methanol solution, 6mol/L sulfuric acid are the same as Appendix A. B2.6 0.05mol/L sulfuric acid: Take 8.3mL of 6mol/L sulfuric acid and slowly inject it into 1000mL of distilled water, and shake well. Instruments or equipment
B3.1 Gas chromatograph: with hydrogen flame ionization detector. B3.2 Stoppered test tubes: 5mL, 10 pieces.
B3.3 Micro syringes: 10μL, 2 pieces. B3.4 Atmospheric sampler, empty box barometer, sampling tube, etc. are the same as Appendix A. B4 Sampling
The sampling operation steps and requirements are the same as Appendix A. B5 Analysis steps
B5.1.1 Preparation of furfural derivatization reagent: Pipette 2mL of freshly distilled aldehyde into a 50mL volumetric flask, dilute to the scale with 0.5mol/L sodium acetate solution, and shake well.
B5.1.2 Preparation of solid adsorbent and sampling tube: Prepare solid adsorbent using 6201 carrier. The steps of boiling, rinsing, acid coating and drying are the same as those in Appendix A.
Weigh 0.20 μl of the sulfuric acid-coated support and inject it into a specially prepared glass sampling tube. The two ends of the twisted body are fixed with clean stainless steel mesh. The two ends of the tube are sealed with polyethylene caps.
B5.1.3 Preparation of standard solution
Take unsymmetrical dimethylhydrazine W with a purity of ℃t and inject it into 0.4 mol/L sulfuric acid with a volume of V to prepare a standard solution of unsymmetrical dimethylhydrazine. The concentration of unsymmetrical dimethylhydrazine (A) can be calculated according to formula (B1). 57
GB180592000
（B1)
Bake hydrazine sulfate at 100°C for 2h, weigh W2, dissolve it in 0.4 mol/L sulfuric acid V, and prepare a standard solution of hydrazine. The concentration of hydrazine (B) can be calculated according to the formula (B2):
0. 246C2 X W2
Wherein: 0.246
Conversion coefficient of hydrazine sulfate and hydrazine;
B5.2 Derivation
Purity of hydrazine sulfate.
·(B2)
After sampling, the solid adsorbent is transferred to a stoppered test tube, eluted with 2ml. distilled water, and then 2mL of furfural derivatization reagent is added. The reaction is carried out at room temperature for 60min, and extracted with 1mL of ethyl acetate for 20min. B5.3 Chromatographic conditions
Chromatographic column: 10% OV-7/supelcoport, 80～100 mesh; 4m×3mm glass column. Flow rate: carrier gas (N,), 50mL/min; fuel gas (H2), 70mL/min; auxiliary gas (air), 500mL/min. The above values are all indicated values of the rotor flowmeter.
Temperature: Column temperature 205℃; Vaporization chamber and detection chamber 315℃. Injection volume: 10μL.
Typical chromatographic peak diagram is shown in Figure B1.
Chromatographic peak diagram of Figure B1 under selected conditions
B5.4 Drawing of standard curve
Take 6 stoppered test tubes, add 0.20g of solid adsorbent and 2ml of distilled water respectively, and add a series of standard solutions of unsymmetrical dimethylhydrazine or hydrazine in sequence. Then add 2ml of furfural derivatization reagent to each, react at room temperature for 60min, extract with 1mL of ethyl acetate for 20min, and absorb 10μl. The extract is injected into the chromatograph for analysis. Draw a standard curve with peak height as the ordinate and sample content as the abscissa. B5.5 Sample determination
GB 18059--2000
Take 10% of the sample extract and inject it into the chromatograph for analysis. Measure the peak height of unsymmetrical dimethylhydrazine and hydrazine, and find out the mass of unsymmetrical dimethylhydrazine and hydrazine in the sample (ug) from the standard curve. Mixed samples of unsymmetrical dimethylhydrazine and hydrazine should be analyzed on the same day after sampling. B6 Calculation
Calculate the concentration of dimethylhydrazine and hydrazine in the atmosphere according to (B3) and (B4):
Where: unsymmetrical dimethylhydrazine concentration, ng/n
C hydrazine concentration nmg/m
a-mass of unsymmetrical dimethylhydrazine contained in the sample solution, μg; 6-mass of hydrazine contained in the sample solution, μg
V. Flow rate corrected to standard state, L/mmtSampling time, min.
Precision or allowable error
The average relative error of unsymmetrical dimethylhydrazine is 9.3%; the average relative error of hydrazine is 3.7%. ·(B3)8 Colorimetry
Use a graduated pipette to absorb 1 mL of the upper clear liquid after desorption and place it in another stoppered graduated tube for standby use. Add 1 mL of TPF color developer to the remaining desorption solution, invert 5 times, and color in the dark for 50 minutes (at 20°C). The dilution factor of this solution is 1.042. Determine the absorbance according to the conditions and steps for making the standard curve. After subtracting the blank average absorbance, find out the mass (μg) of unsymmetrical dimethylhydrazine contained in the solution from the standard curve.
If the color depth exceeds the measurement range, add 15 mL of pH 5.4 buffer solution and 1 mL of TPF color developer to the standby 1 mL sample, dilute to the scale with pH 5.4 buffer, invert 5 times, and color in the dark after measuring the absorbance. The dilution factor of this solution is 25. A6 Result calculation
Calculate the concentration of unsymmetrical dimethylhydrazine in the atmosphere according to formula (A1). c= n ×WX1: 013 X10 X(273 ± T)Q × t × Pr × 273
W——-the mass of UDMH contained in the solution, ug; Q-sampling flow, L/min;
tsampling time, min;
Pr——atmospheric pressure at sampling, Pa;
T——ambient temperature at sampling, °C.
A7 Precision or allowable error
. (Al)
When the concentration of UDMH is lower than 0.134mg/m2, the relative standard deviation is not more than 16%; when the concentration is 0.134~5.46mg/m, the relative standard deviation is not more than 5.0%. Notes
1 The pH value of the pH 6.2 buffer solution should be adjusted in advance for each batch of support to ensure that the pH of the tested solution is 5.4 ± 0.2. 1
The ambient temperature affects both the color development time and the color stability. The color development time can be selected according to the table below, or the color development time can be 20 minutes in a 30°C constant temperature water bath. Temperature, c
Time.min
B1 Principle
GB18059—2000
Appendix B
(Appendix of the standard)
Monitoring and testing methods for unsymmetrical dimethyl hydrazine in the atmosphere Solid adsorption/gas chromatography method Use a solid adsorbent coated with sulfuric acid to capture unsymmetrical dimethyl hydrazine in the air, then elute with water, add furfural derivatization reagent, and generate unsymmetrical dimethyl derivatives. Extract with ethyl acetate and analyze with a gas chromatograph. Calculate the content of unsymmetrical dimethyl hydrazine based on the peak height. This method can be determined simultaneously.
Measurement range: unsymmetrical dimethyl hydrazine 0.026-~6.7mz/m; hydrazine 0.00714～1.00mg/m. The upper limit of determination can be extended. The minimum detection concentration of the method: unsymmetrical dimethyl hydrazine is 0.0208mg/m when sampling 120L, and 0. 007 2 mg/m when sampling 60L
B2 Reagents or materials
B2.1 Furfural: analytical grade.
B2.2 Ethyl acetate: analytical grade.
B2.3 Sodium acetate: analytical grade.
B2.4 Sulfuric acid: analytical grade.
B2.5 Sulfuric acid, methanol, 6201 support, unsymmetrical dimethyl hydrazine, sulfuric acid-methanol solution, 6mol/L sulfuric acid are the same as Appendix A. B2.6 0.05mol/L sulfuric acid: Take 8.3mL of 6mol/L sulfuric acid and slowly inject it into 1000mL of distilled water, and shake well. Instruments or equipment
B3.1 Gas chromatograph: with hydrogen flame ionization detector. B3.2 Stoppered test tubes: 5mL, 10 pieces.
B3.3 Micro syringes: 10μL, 2 pieces. B3.4 Atmospheric sampler, empty box barometer, sampling tube, etc. are the same as Appendix A. B4 Sampling
The sampling operation steps and requirements are the same as Appendix A. B5 Analysis steps
B5.1.1 Preparation of furfural derivatization reagent: Pipette 2mL of freshly distilled aldehyde into a 50mL volumetric flask, dilute to the scale with 0.5mol/L sodium acetate solution, and shake well.
B5.1.2 Preparation of solid adsorbent and sampling tube: Prepare solid adsorbent using 6201 carrier. The steps of boiling, rinsing, acid coating and drying are the same as those in Appendix A.
Weigh 0.20 μl of the sulfuric acid-coated support and inject it into a specially prepared glass sampling tube. The two ends of the twisted body are fixed with clean stainless steel mesh. The two ends of the tube are sealed with polyethylene caps.
B5.1.3 Preparation of standard solution
Take unsymmetrical dimethylhydrazine W with a purity of ℃t and inject it into 0.4 mol/L sulfuric acid with a volume of V to prepare a standard solution of unsymmetrical dimethylhydrazine. The concentration of unsymmetrical dimethylhydrazine (A) can be calculated according to formula (B1). 57
GB180592000
（B1)
Bake hydrazine sulfate at 100°C for 2h, weigh W2, dissolve it in 0.4 mol/L sulfuric acid V, and prepare a standard solution of hydrazine. The concentration of hydrazine (B) can be calculated according to the formula (B2):
0. 246C2 X W2
Wherein: 0.246
Conversion coefficient of hydrazine sulfate and hydrazine;
B5.2 Derivation
Purity of hydrazine sulfate.
·(B2)
After sampling, the solid adsorbent is transferred to a stoppered test tube, eluted with 2ml. distilled water, and then 2mL of furfural derivatization reagent is added. The reaction is carried out at room temperature for 60min, and extracted with 1mL of ethyl acetate for 20min. B5.3 Chromatographic conditions
Chromatographic column: 10% OV-7/supelcoport, 80～100 mesh; 4m×3mm glass column. Flow rate: carrier gas (N,), 50mL/min; fuel gas (H2), 70mL/min; auxiliary gas (air), 500mL/min. The above values are all indicated values of the rotor flowmeter.
Temperature: Column temperature 205℃; Vaporization chamber and detection chamber 315℃. Injection volume: 10μL.
Typical chromatographic peak diagram is shown in Figure B1.
Chromatographic peak diagram of Figure B1 under selected conditions
B5.4 Drawing of standard curve
Take 6 stoppered test tubes, add 0.20g of solid adsorbent and 2ml of distilled water respectively, and add a series of standard solutions of unsymmetrical dimethylhydrazine or hydrazine in sequence. Then add 2ml of furfural derivatization reagent to each, react at room temperature for 60min, extract with 1mL of ethyl acetate for 20min, and absorb 10μl. The extract is injected into the chromatograph for analysis. Draw a standard curve with peak height as the ordinate and sample content as the abscissa. B5.5 Sample determination
GB 18059--2000
Take 10% of the sample extract and inject it into the chromatograph for analysis. Measure the peak height of unsymmetrical dimethylhydrazine and hydrazine, and find out the mass of unsymmetrical dimethylhydrazine and hydrazine in the sample (ug) from the standard curve. Mixed samples of unsymmetrical dimethylhydrazine and hydrazine should be analyzed on the same day after sampling. B6 Calculation
Calculate the concentration of dimethylhydrazine and hydrazine in the atmosphere according to (B3) and (B4):
Where: unsymmetrical dimethylhydrazine concentration, ng/n
C hydrazine concentration nmg/m
a-mass of unsymmetrical dimethylhydrazine contained in the sample solution, μg; 6-mass of hydrazine contained in the sample solution, μg
V. Flow rate corrected to standard state, L/mmtSampling time, min.
Precision or allowable error
The average relative error of unsymmetrical dimethylhydrazine is 9.3%; the average relative error of hydrazine is 3.7%. ·(B3)2 pH value of buffer solution to ensure that the pH of the solution being tested is 5.4 ± 0.2. 1
Ambient temperature affects both the color development time and color stability. The color development time can be selected according to the table below, or a 30°C constant temperature water bath can be used for color development for 20 minutes. Temperature, c
Time.min
B1 Principle
GB18059—2000
Appendix B
(Appendix of the standard)bzxz.net
Monitoring and testing methods for unsymmetrical dimethyl hydrazine in the atmosphere Solid adsorption/gas chromatography method Use a solid adsorbent coated with sulfuric acid to capture unsymmetrical dimethyl hydrazine in the air, then elute with water, add furfural derivatization reagent, and generate unsymmetrical dimethyl derivatives. Extract with ethyl acetate and analyze with a gas chromatograph. Calculate the content of unsymmetrical dimethyl hydrazine based on the peak height. This method can be determined simultaneously.
Measurement range: unsymmetrical dimethyl hydrazine 0.026-~6.7mz/m; hydrazine 0.00714～1.00mg/m. The upper limit of determination can be extended. The minimum detection concentration of the method: unsymmetrical dimethyl hydrazine is 0.0208mg/m when sampling 120L, and 0. 007 2 mg/m when sampling 60L
B2 Reagents or materials
B2.1 Furfural: analytical grade.
B2.2 Ethyl acetate: analytical grade.
B2.3 Sodium acetate: analytical grade.
B2.4 Sulfuric acid: analytical grade.
B2.5 Sulfuric acid, methanol, 6201 support, unsymmetrical dimethyl hydrazine, sulfuric acid-methanol solution, 6mol/L sulfuric acid are the same as Appendix A. B2.6 0.05mol/L sulfuric acid: Take 8.3mL of 6mol/L sulfuric acid and slowly inject it into 1000mL of distilled water, and shake well. Instruments or equipment
B3.1 Gas chromatograph: with hydrogen flame ionization detector. B3.2 Stoppered test tubes: 5mL, 10 pieces.
B3.3 Micro syringes: 10μL, 2 pieces. B3.4 Atmospheric sampler, empty box barometer, sampling tube, etc. are the same as Appendix A. B4 Sampling
The sampling operation steps and requirements are the same as Appendix A. B5 Analysis steps
B5.1.1 Preparation of furfural derivatization reagent: Pipette 2mL of freshly distilled aldehyde into a 50mL volumetric flask, dilute to the scale with 0.5mol/L sodium acetate solution, and shake well.
B5.1.2 Preparation of solid adsorbent and sampling tube: Prepare solid adsorbent using 6201 carrier. The steps of boiling, rinsing, acid coating and drying are the same as those in Appendix A.
Weigh 0.20 μl of the sulfuric acid-coated support and inject it into a specially prepared glass sampling tube. The two ends of the twisted body are fixed with clean stainless steel mesh. The two ends of the tube are sealed with polyethylene caps.
B5.1.3 Preparation of standard solution
Take unsymmetrical dimethylhydrazine W with a purity of ℃t and inject it into 0.4 mol/L sulfuric acid with a volume of V to prepare a standard solution of unsymmetrical dimethylhydrazine. The concentration of unsymmetrical dimethylhydrazine (A) can be calculated according to formula (B1). 57
GB180592000
（B1)
Bake hydrazine sulfate at 100°C for 2h, weigh W2, dissolve it in 0.4 mol/L sulfuric acid V, and prepare a standard solution of hydrazine. The concentration of hydrazine (B) can be calculated according to the formula (B2):
0. 246C2 X W2
Wherein: 0.246
Conversion coefficient of hydrazine sulfate and hydrazine;
B5.2 Derivation
Purity of hydrazine sulfate.
·(B2)
After sampling, the solid adsorbent is transferred to a stoppered test tube, eluted with 2ml. distilled water, and then 2mL of furfural derivatization reagent is added. The reaction is carried out at room temperature for 60min, and extracted with 1mL of ethyl acetate for 20min. B5.3 Chromatographic conditions
Chromatographic column: 10% OV-7/supelcoport, 80～100 mesh; 4m×3mm glass column. Flow rate: carrier gas (N,), 50mL/min; fuel gas (H2), 70mL/min; auxiliary gas (air), 500mL/min. The above values are all indicated values of the rotor flowmeter.
Temperature: Column temperature 205℃; Vaporization chamber and detection chamber 315℃. Injection volume: 10μL.
Typical chromatographic peak diagram is shown in Figure B1.
Chromatographic peak diagram of Figure B1 under selected conditions
B5.4 Drawing of standard curve
Take 6 stoppered test tubes, add 0.20g of solid adsorbent and 2ml of distilled water respectively, and add a series of standard solutions of unsymmetrical dimethylhydrazine or hydrazine in sequence. Then add 2ml of furfural derivatization reagent to each, react at room temperature for 60min, extract with 1mL of ethyl acetate for 20min, and absorb 10μl. The extract is injected into the chromatograph for analysis. Draw a standard curve with peak height as the ordinate and sample content as the abscissa. B5.5 Sample determination
GB 18059--2000
Take 10% of the sample extract and inject it into the chromatograph for analysis. Measure the peak height of unsymmetrical dimethylhydrazine and hydrazine, and find out the mass of unsymmetrical dimethylhydrazine and hydrazine in the sample (ug) from the standard curve. Mixed samples of unsymmetrical dimethylhydrazine and hydrazine should be analyzed on the same day after sampling. B6 Calculation
Calculate the concentration of dimethylhydrazine and hydrazine in the atmosphere according to (B3) and (B4):
Where: unsymmetrical dimethylhydrazine concentration, ng/n
C hydrazine concentration nmg/m
a-mass of unsymmetrical dimethylhydrazine contained in the sample solution, μg; 6-mass of hydrazine contained in the sample solution, μg
V. Flow rate corrected to standard state, L/mmtSampling time, min.
Precision or allowable error
The average relative error of unsymmetrical dimethylhydrazine is 9.3%; the average relative error of hydrazine is 3.7%. ·(B3)2 pH value of buffer solution to ensure that the pH of the solution being tested is 5.4 ± 0.2. 1
Ambient temperature affects both the color development time and color stability. The color development time can be selected according to the table below, or a 30°C constant temperature water bath can be used for color development for 20 minutes. Temperature, c
Time.min
B1 Principle
GB18059—2000
Appendix B
(Appendix of the standard)
Monitoring and testing methods for unsymmetrical dimethyl hydrazine in the atmosphere Solid adsorption/gas chromatography method Use a solid adsorbent coated with sulfuric acid to capture unsymmetrical dimethyl hydrazine in the air, then elute with water, add furfural derivatization reagent, and generate unsymmetrical dimethyl derivatives. Extract with ethyl acetate and analyze with a gas chromatograph. Calculate the content of unsymmetrical dimethyl hydrazine based on the peak height. This method can be determined simultaneously.
Measurement range: unsymmetrical dimethyl hydrazine 0.026-~6.7mz/m; hydrazine 0.00714～1.00mg/m. The upper limit of determination can be extended. The minimum detection concentration of the method: unsymmetrical dimethyl hydrazine is 0.0208mg/m when sampling 120L, and 0. 007 2 mg/m when sampling 60L
B2 Reagents or materials
B2.1 Furfural: analytical grade.
B2.2 Ethyl acetate: analytical grade.
B2.3 Sodium acetate: analytical grade.
B2.4 Sulfuric acid: analytical grade.
B2.5 Sulfuric acid, methanol, 6201 support, unsymmetrical dimethyl hydrazine, sulfuric acid-methanol solution, 6mol/L sulfuric acid are the same as Appendix A. B2.6 0.05mol/L sulfuric acid: Take 8.3mL of 6mol/L sulfuric acid and slowly inject it into 1000mL of distilled water, and shake well. Instruments or equipment
B3.1 Gas chromatograph: with hydrogen flame ionization detector. B3.2 Stoppered test tubes: 5mL, 10 pieces.
B3.3 Micro syringes: 10μL, 2 pieces. B3.4 Atmospheric sampler, empty box barometer, sampling tube, etc. are the same as Appendix A. B4 Sampling
The sampling operation steps and requirements are the same as Appendix A. B5 Analysis steps
B5.1.1 Preparation of furfural derivatization reagent: Pipette 2mL of freshly distilled aldehyde into a 50mL volumetric flask, dilute to the scale with 0.5mol/L sodium acetate solution, and shake well.
B5.1.2 Preparation of solid adsorbent and sampling tube: Prepare solid adsorbent using 6201 carrier. The steps of boiling, rinsing, acid coating and drying are the same as those in Appendix A.
Weigh 0.20 μl of the sulfuric acid-coated support and inject it into a specially prepared glass sampling tube. The two ends of the twisted body are fixed with clean stainless steel mesh. The two ends of the tube are sealed with polyethylene caps.
B5.1.3 Preparation of standard solution
Take unsymmetrical dimethylhydrazine W with a purity of ℃t and inject it into 0.4 mol/L sulfuric acid with a volume of V to prepare a standard solution of unsymmetrical dimethylhydrazine. The concentration of unsymmetrical dimethylhydrazine (A) can be calculated according to formula (B1). 57
GB180592000
（B1)
Bake hydrazine sulfate at 100°C for 2h, weigh W2, dissolve it in 0.4 mol/L sulfuric acid V, and prepare a standard solution of hydrazine. The concentration of hydrazine (B) can be calculated according to the formula (B2):
0. 246C2 X W2
Wherein: 0.246
Conversion coefficient of hydrazine sulfate and hydrazine;
B5.2 Derivation
Purity of hydrazine sulfate.
·(B2)
After sampling, the solid adsorbent is transferred to a stoppered test tube, eluted with 2ml. distilled water, and then 2mL of furfural derivatization reagent is added. The reaction is carried out at room temperature for 60min, and extracted with 1mL of ethyl acetate for 20min. B5.3 Chromatographic conditions
Chromatographic column: 10% OV-7/supelcoport, 80～100 mesh; 4m×3mm glass column. Flow rate: carrier gas (N,), 50mL/min; fuel gas (H2), 70mL/min; auxiliary gas (air), 500mL/min. The above values are all indicated values of the rotor flowmeter.
Temperature: Column temperature 205℃; Vaporization chamber and detection chamber 315℃. Injection volume: 10μL.
Typical chromatographic peak diagram is shown in Figure B1.
Chromatographic peak diagram of Figure B1 under selected conditions
B5.4 Drawing of standard curve
Take 6 stoppered test tubes, add 0.20g of solid adsorbent and 2ml of distilled water respectively, and add a series of standard solutions of unsymmetrical dimethylhydrazine or hydrazine in sequence. Then add 2ml of furfural derivatization reagent to each, react at room temperature for 60min, extract with 1mL of ethyl acetate for 20min, and absorb 10μl. The extract is injected into the chromatograph for analysis. Draw a standard curve with peak height as the ordinate and sample content as the abscissa. B5.5 Sample determination
GB 18059--2000
Take 10% of the sample extract and inject it into the chromatograph for analysis. Measure the peak height of unsymmetrical dimethylhydrazine and hydrazine, and find out the mass of unsymmetrical dimethylhydrazine and hydrazine in the sample (ug) from the standard curve. Mixed samples of unsymmetrical dimethylhydrazine and hydrazine should be analyzed on the same day after sampling. B6 Calculation
Calculate the concentration of dimethylhydrazine and hydrazine in the atmosphere according to (B3) and (B4):
Where: unsymmetrical dimethylhydrazine concentration, ng/n
C hydrazine concentration nmg/m
a-mass of unsymmetrical dimethylhydrazine contained in the sample solution, μg; 6-mass of hydrazine contained in the sample solution, μg
V. Flow rate corrected to standard state, L/mmtSampling time, min.
Precision or allowable error
The average relative error of unsymmetrical dimethylhydrazine is 9.3%; the average relative error of hydrazine is 3.7%. ·(B3)246
Conversion coefficient of hydrazine sulfate and hydrazine;
B5.2 Derivation
Purity of hydrazine sulfate.
·(B2)
After sampling, transfer the solid adsorbent into a stoppered test tube, elute with 2ml. distilled water, add 2mL furfural derivatization reagent, react at room temperature for 60min, and extract with 1mL ethyl acetate for 20min. B5.3 Chromatographic conditions
Chromatographic column: 10% OV-7/supelcoport, 80～100 mesh; 4m×3mm glass column. Flow rate: carrier gas (N,), 50mL/min; fuel gas (H2), 70mL/min; auxiliary gas (air), 500mL/min. The above values are all indicated values of the rotor flowmeter.
Temperature: column temperature 205℃; vaporization chamber and detection chamber are 315℃. Injection volume: 10μL.
A typical chromatographic peak diagram is shown in Figure B1.
Figure B1 Chromatographic peak diagram under selected conditions
B5.4 Drawing of standard curve
Take 6 stoppered test tubes, add 0.20g of solid adsorbent and 2ml of distilled water respectively, and add a series of standard solutions of unsymmetrical dimethylhydrazine or hydrazine in turn. Then add 2ml of furfural derivatization reagent to each tube, react at room temperature for 60min, extract with 1mL of ethyl acetate for 20min, and absorb 10μl. The extract is injected into the chromatograph for analysis. The standard curve is drawn with the peak height as the ordinate and the sample content as the abscissa. B5.5 Sample determination
GB 18059--2000
Take the extracts of 10 samples to be tested, inject them into the chromatograph for analysis, measure the peak height of unsymmetrical dimethylhydrazine and hydrazine, and find out the mass of unsymmetrical dimethylhydrazine and hydrazine in the sample (ug) from the standard curve. The mixed sample of unsymmetrical dimethylhydrazine and hydrazine should be analyzed on the same day after sampling. B6 Nesting calculation
Calculate the concentration of dimethyl hydrazine and hydrazine in the atmosphere according to (B3) and (B4):
Where: unsymmetrical dimethylhydrazine concentration, ng/n
C hydrazine concentration nmg/m
a-the mass of unsymmetrical dimethylhydrazine contained in the sample solution, μg; 6 the mass of hydrazine contained in the sample solution, μg
V. Flow rate corrected to standard state, L/mmt Sampling time, min.
Precision or allowable error
The average relative error of unsymmetrical dimethylhydrazine is 9.3%; the average relative error of hydrazine is 3.7%. ·(B3)246
Conversion coefficient of hydrazine sulfate and hydrazine;
B5.2 Derivation
Purity of hydrazine sulfate.
·(B2)
After sampling, transfer the solid adsorbent into a stoppered test tube, elute with 2ml. distilled water, add 2mL furfural derivatization reagent, react at room temperature for 60min, and extract with 1mL ethyl acetate for 20min. B5.3 Chromatographic conditions
Chromatographic column: 10% OV-7/supelcoport, 80～100 mesh; 4m×3mm glass column. Flow rate: carrier gas (N,), 50mL/min; fuel gas (H2), 70mL/min; auxiliary gas (air), 500mL/min. The above values are all indicated values of the rotor flowmeter.
Temperature: column temperature 205℃; vaporization chamber and detection chamber are 315℃. Injection volume: 10μL.
A typical chromatographic peak diagram is shown in Figure B1.
Figure B1 Chromatographic peak diagram under selected conditions
B5.4 Drawing of standard curve
Take 6 stoppered test tubes, add 0.20g of solid adsorbent and 2ml of distilled water respectively, and add a series of standard solutions of unsymmetrical dimethylhydrazine or hydrazine in turn. Then add 2ml of furfural derivatization reagent to each tube, react at room temperature for 60min, extract with 1mL of ethyl acetate for 20min, and absorb 10μl. The extract is injected into the chromatograph for analysis. The standard curve is drawn with the peak height as the ordinate and the sample content as the abscissa. B5.5 Sample determination
GB 18059--2000
Take the extracts of 10 samples to be tested, inject them into the chromatograph for analysis, measure the peak height of unsymmetrical dimethylhydrazine and hydrazine, and find out the mass of unsymmetrical dimethylhydrazine and hydrazine in the sample (ug) from the standard curve. The mixed sample of unsymmetrical dimethylhydrazine and hydrazine should be analyzed on the same day after sampling. B6 Nesting calculation
Calculate the concentration of dimethyl hydrazine and hydrazine in the atmosphere according to (B3) and (B4):
Where: unsymmetrical dimethylhydrazine concentration, ng/n
C hydrazine concentration nmg/m
a-the mass of unsymmetrical dimethylhydrazine contained in the sample solution, μg; 6 the mass of hydrazine contained in the sample solution, μg
V. Flow rate corrected to standard state, L/mmt Sampling time, min.
Precision or allowable error
The average relative error of unsymmetrical dimethylhydrazine is 9.3%; the average relative error of hydrazine is 3.7%. ·(B3)
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