GB 18063-2000 Hygienic standard for unsymmetrical dimethylhydrazine in source water
Some standard content:
GB18063—2000
The technical contents of this standard are mandatory. In order to implement the "Environmental Protection Law of the People's Republic of China" and the "Water Pollution Prevention and Control Law of the People's Republic of China", prevent the pollution of the aerospace industry to the water environment, protect the health of the general public, this standard is formulated according to the principles of formulating water source hygiene standards, with reference to foreign research results, and based on my country's actual situation.
This standard shall be implemented from January 2001. This standard was proposed by the Ministry of Health of the People's Republic of China and the Ministry of Aerospace Industry. Appendix A of this standard is the appendix to the standard.
Responsible drafting unit of this standard: The Seventh Design Institute of the Ministry of Aerospace Industry; Participating units: {. Haidi--Medical College, 806 Institute of Shanghai Aerospace Administration, Academy of Military Medical Sciences of the Chinese People's Liberation Army; Main drafters of this standard: Xu Zhitong, Chen Bingheng, Xi Huimin, Du Yadong, Wang Lan. This standard is entrusted by the Ministry of Health to the Environmental Health and Dust Monitoring Institute of the Chinese Academy of Preventive Medicine for interpretation. 1 Scope
National Standard of the People's Republic of China
Hygienic standard for unsymmetrical dinethylhydrazine in water
Hygienic standard for unsymmetrical dinethylhydrazine in water sources
GB18063—2000
This standard specifies the maximum permissible concentration of unsymmetrical dimethylhydrazine in drinking water source water and the monitoring and testing methods. This standard is applicable to drinking water sources such as rivers, lakes, reservoirs, ponds (wells). 2
In the standard
The maximum permissible concentration of unsymmetrical dimethylhydrazine in drinking water source water is 0.1 mg/L3
Detection method
This standard adopts the sodium aminoferrocyanide spectrophotometry method to detect unsymmetrical dimethylhydrazine in water, see Appendix A (Appendix to the standard). Approved by the State Administration of Quality Supervision, Inspection and Quarantine on April 10, 2000, implemented on January 1, 2001
A1 Method Summary
GB 18063—2000
Appendix A
(Appendix with standard recommendation)
Determination of unsymmetrical monomethylhydrazine in water by sodium ferrous oxide spectrophotometry. Unsymmetrical dimethylhydrazine and sodium ferrous oxide can form a red complex in a weakly acidic aqueous solution. Within the measurement range, the depth of red is proportional to the content of unsymmetrical dimethylhydrazine, which conforms to the Lambert-Beer law. The maximum absorption wavelength of the red complex is 500nm. Nitrogen and urea have basically no interference with the determination of this method. Hydrazine, -methylhydrazine and formaldehyde have no interference within 5 times the content of unsymmetrical dimethylhydrazine. Nitrite content has obvious negative interference when it is more than 2 times the content of unsymmetrical dimethylhydrazine. Aminosulfonic acid amine is selected as a masking agent. When the water sample is mixed, it should be filtered.
The determination range of unsymmetrical dimethylhydrazine: 0. (I1 mg/L~1. 0 mg/L-. Unsymmetrical dimethylhydrazine below 1. 0 mg/I Methyl alcohol can be diluted and measured according to this method.
A2 Apparatus and instruments
A2.1 Spectrophotometer: with 5cm colorimetric tube, A2.2 Pressure regulator: TDGC2 type.
A2.3 Electrode: 1 000 W.
A2.4 Nitrogen cylinder containing 99.99% nitrogen.
A2.5 Oxygen inhaler: 1.08-32 float oxygen inhaler. Vacuum pump: DYB-1 type.
Water bath: DL501 super constant temperature water bath,
42.8 Grinding 11 Distiller: 1000mL, 1 set
A2.9 Ground airway: 1,
A2.10 Micro syringe: 100μL..3. The stoppered graduated tube: 50 ml., 10 pcs.
Vacuum drying,
Graduate pipette: 1mL, 3;2nL, 1 pc 5 ml, 1 pc, 10 ml, 1 pc. 42.14 Drying tower: 500 mL, 2 pcs,
A2.15 Sand core filter funnel: No. 4.
Reagents and preparation methods
43.1Sodium hydroxide: chemically pure.
A3.2Sodium chloride: chemically pure
A3.3Citric acid (L,H,O,·HO): analytically pure. A3.4Disodium ammonium phosphate (Na,HPO.12H,O): analytically pure. A3.5Sodium nitrosohydride _NaFe (CNV), NO·2H.O]: analytically pure A3.6Sulfuric acid: analytically pure.
A3.7 Methanol: analytical grade.
A3.8 Ammonia water: analytical grade.
43.9 Sodium chloride: analytical grade.
A3.10 Dimethylamine: containing more than 98%.
GB18063—2000
A3.115% ammonium sulfamate (ammonium sulfamate, NH, SO, NH,) solution A3.1212mol/L sulfuric acid: In a 100mL volumetric flask, add 50mL distilled water, carefully add 33.3mL concentrated sulfuric acid, dilute to the mark with distilled water + shake well.
A3.13 Preparation of sodium aminoferricyanide (TPF) (sodiumaminoferricyanide.Na: [Fc(CN),Nil.]: Weigh 45g of sodium nitrosoferric oxide into a 250 mL conical flask, gradually add 140 mL of ammonia water, shaking while adding until all dissolved. Place the flask in a refrigerator at about 0℃ overnight, add 250 mL of mL of methanol, yellow crystals will precipitate, filter out the crystals, drain, and then wash with methanol. The obtained crystals are placed in a brown vacuum dryer filled with calcium chloride and dried for 4 to 6 hours. The dried sodium ferrocyanide is placed in a brown fine bottle and stored in a dark place.
A3.14 Preparation of 0.15% TPF color developer: In a 100ml brown volumetric flask, dissolve 0.15g TPF with distilled water and dilute to scale.
A3.15 Preparation of PH4.8 buffer solution: Weigh 13.138g of citric acid and 48.868g of disodium hydrogen phosphate and dissolve them in 150mL of boiled distilled water. Transfer them to a 250mL volumetric flask and dilute to scale with boiled distilled water. A3. 16 Preparation of dimethyl methoxide standard stock solution: Add 25ml of distilled water and 5mol/L of 12 mol/L sulfuric acid to a 50mL volumetric flask. mL, cover with stopper, shake the hook. Use a microsyringe to take 65 μl of unsymmetrical dimethylhydrazine, store in a volumetric flask, and weigh 0.050 μg of unsymmetrical dimethylhydrazine by the incremental method. Gently shake the volumetric flask to fully dissolve the unsymmetrical monomethylhydrazine. After 20 minutes, dilute to the mark with distilled water. It can be stored for two weeks at room temperature. The unsymmetrical dimethylhydrazine content of this solution is 1 mg/L. A3.17 Preparation of unsymmetrical dimethylhydrazine working solution: In a 1000mL flask, add 1.0mL of unsymmetrical dimethylhydrazine standard stock solution and dilute to the mark with distilled water. The unsymmetrical dimethylhydrazine content of this solution is 1ug/mL water and can be stored for one week at room temperature. A3.18 Sample preservation: It is best to test the water sample on the same day. When preservation is necessary, 1.8mol/L c(HSO,) sulfuric acid solution can be added to the water sample at 1 liter. ml, this water sample can be placed for 1 day,
A4 Analysis steps
A4.1 Drawing of standard curve
Take 6 50 mL stoppered graduated tubes, and respectively put in 0.0, 2.0, 5.0, 7.0, 10.0, 13.0 mL of unsymmetrical monomethylhydrazine working solution. Then add distilled water to each tube to 25 mL, add 1 mL of pH buffer solution and 1 mL of 0.15% TPF color developer. Shake the hook. When the nitrite content in the water sample is more than 2 times that of unsymmetrical dimethylhydrazine, after adding the pH buffer solution, add 0.2 mL of 5% aminosulfonic acid to each tube, and then add 1 mL of color developer. Put the colorimetric tube in a 30℃ constant temperature water bath and leave it for 1 hour. Use 5 at 500 nm on the spectrophotometer. cm colorimetric III absorbance determination report According to the measured absorbance, draw a standard working curve for the corresponding unsymmetrical monomethylhydrazine content and find the reproducible equation. A4.2 Water sample determination
A4.2.1 Determination of unsymmetrical dimethylhydrazine content in water samples above 50 g/L A4.2.1.1 First adjust the pH of the water sample to 3.0~8.0. When the water sample is turbid, filter it with a 4-gauge sand core funnel. Take an appropriate volume of the above-mentioned pre-treated water sample into a stoppered graduated tube, dilute it to 25 tL with distilled water, and then determine it according to step A1.1. According to the measured absorbance, calculate the unsymmetrical dimethylhydrazine content by using the standard working curve equation or by checking the standard working curve method.
44.2.1.2 Calculate the unsymmetrical dimethylhydrazine content of the water sample according to formula (A1) G=CXn
Formula: cx-unsymmetrical dimethylhydrazine content of the water sample,μg/mnL; co—-the mass of unsymmetrical dimethylhydrazine contained in the water sample calculated in A4.2.1.1, g; n——dilution factor;
V—-the volume of the water sample taken for colorimetry, mL. A4.2.2 Determination of unsymmetrical dimethylhydrazine content in water sample less than 50μg/L.-(Al
A4.2.2.1 Collection of water sample (distillation concentration method) The distillation method is shown in Figure 1.
GB18063-2000bzxZ.net
In a 1000ml round-bottom flask, add 90g sodium fluoride and 120g sodium hydroxide, pass nitrogen at a flow rate of 50ml./min for 15min, take 500ml of water sample and inject it into the flask, shake it gently for a few times, and then heat distill. Continue to pass nitrogen, connect cooling water, and use a graduated tube to collect condensate at the condensation port. When the water sample is about to boil, adjust the voltage of the voltage regulator to 150V to control the electric heating temperature so that the outflow time of each 25mL fraction is between 11~-15 IImin, collect 3 tubes of fractions continuously, and collect 25mL accurately in each tube, according to A4.2. 1 Measure the content of unsymmetrical dimethylhydrazine in each tube.
1-Fluorine gas bottle; 2-Oxygen inhaler (A-decompression chamber, B-flowmeter, C-needle condenser); 3-lower drying tower; 4-desiccant; 5-seed bottle; G-air guide tube; 7-branch flask; 8-serpentine condenser; 9-colorimetric tube; 10-electric furnace; 11-pressure regulator Figure 1 Flow chart of distillation device
A4. 2-2.2 Calculate the unsymmetrical dimethylhydrazine content of the water sample according to formula (A2). E
W,+W,+Ws
- unsymmetrical dimethylhydrazine content in the water sample, g/mL; WI.W2,W3.- are the weight of unsymmetrical dimethylhydrazine contained in three graduated tubes containing fractions, g; the volume of 500 distilled water sample, mL;
N—- recovery rate, 71%.
A4.2.3 Take the arithmetic mean of the two results of parallel determination as the unsymmetrical dimethylhydrazine content in the water sample. A5 Allowable difference
For water samples with different unsymmetrical dimethylhydrazine contents, the allowable difference of the analysis results is shown in Table 1. :com (A2)
Unsymmetrical dimethylhydrazine content range, mg/,
0. 01--0. 1
>0. 1~1, 0
GB18063—2000
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Allowance difference·%
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