Some standard content:
National Standard of the People's Republic of China
Health standard for nitroglycerine in the air of workplace
Subject content and scope of application
This standard specifies the maximum permissible concentration of nitroglycerine in the air of workplace and its monitoring and inspection methods. This standard applies to all types of enterprises that produce and use nitroglycerine. 2 Hygiene requirements
The maximum permissible concentration of nitroglycerine in the air of workplace is 1mg/m (skin). 3 Monitoring and inspection methods
GB 16212--1996
The monitoring and inspection methods of this standard adopt gas chromatography [see Appendix A (Supplement)) and naphthylethylenediamine hydrochloride colorimetry [see Appendix B (Supplement)].
Approved by the State Administration of Technical Supervision on April 3, 1996 460
Implemented on September 1, 1996
A1 Principle
GB16212-1996
Appendix A
Gas chromatography
(Supplement)
Nitroglycerin in narrow gas is adsorbed by GDX-103, desorbed by anhydrous ethanol, separated by OV-17 chromatographic column, and detected by electron capture detector. Qualitative analysis is performed by retention time, and quantitative analysis is performed by peak height.
A2 Instrument
A2.1 Sampling tube: In a hard glass tube with a length of 10 cm and an inner diameter of 4 mm, 40-60 mesh GDX-103 is placed in the front and back sections, 100 mg in the front section and 50 mg in the back section. The middle section is separated by glass wool, and the two ends are fixed with glass wool. Put on plastic caps for later use or seal them for storage. A2.2 Sampling pump, 0~1.5L/min.
A2.3 Micro-address injector, 10μL, 1μL. A2.4 Cold test tube, 5ml.
A2.5 Gas chromatograph, 63Ni electron capture detector. Chromatographic column: column length 1.1m, inner diameter 3.2mm, glass column. 0V-17: shimaliteW (AW-DMCS) carrier = 1.5: 100 Column temperature: 155℃
Vaporization chamber temperature: 160℃.
Detection chamber temperature: 310℃.
Carrier gas (nitrogen): 100mL/min.
A3 Reagents
A3.1 Nitroglycerin: pure, no impurity peaks in chromatographic identification. A3.2 Anhydrous ethanol, analytical grade.
A3.3GI)X-103: polymer porous microspheres, 40-60 mesh. Before use, take a certain amount into a stoppered triangular flask, add anhydrous ethanol to a height of 2-3 cm, soak for 30 minutes (shake several times in the middle), and filter. Repeat this three times. After determining that there is no interference from impurities in the filtered anhydrous ethanol, dry it at 102-105°C for 25 minutes, put it into a glass or plastic bottle, and seal it for use. A3.4V-17, chromatographic stationary liquid.
A3.5shimaliteW (AW-DMCS) carrier, 80100 days. A4 Sampling
Open the sampling tube at the sampling site, connect the 50mg end of the sampling tube to the sampling pump and place it vertically, and extract 51. air at a speed of 0.5L/min. After sampling, put plastic caps on both ends of the tube and take it back to the laboratory for analysis. A5 Analysis steps
A5.1 Control test: Treat the unsampled GDX-103 sampling tube (A2.1) in the same way as A5.2 as a blank control. A5.2 Sample treatment: Pour the front section and the back section of GDX-103 into the stoppered test tube (A2.4), add 1mL of anhydrous ethanol, immediately stopper, and let stand for 30 minutes (shake several times in between) before analysis. A5.3 Standard curve drawing: Take 5~~10mL of anhydrous ethanol and put it into a 25mL volumetric flask, and weigh it accurately. Use a 1mL dry pipette, press the upper I with the index finger, insert the water layer covering the nitroglycerin into the nitroglycerin layer, release the index finger to absorb a certain amount of nitroglycerin, take out the pipette and wipe the liquid on the wall of the F tube with 461
GB 16212--1996
filter paper. Discard 1-2 drops at the tip of the pipette, then put 2-3 drops into the weighed 25mL volumetric bottle, and quickly weigh the weight increase on the balance. Dilute to the scale with ethanol to prepare the nitroglycerin standard stock solution. When used, dilute with anhydrous ethanol to a standard application solution with a concentration of 1.0, 2.5.5.0, 10.0, 20.01g/ml, and take 1uL for injection. Repeat 3 times for each concentration, take the average value of the peak height, and plot the nitroglycerin content against the peak height, draw a standard curve, and use the retention time as a qualitative indicator. A5.4 Determination: Take 1 μL of the desorbed liquid treated in A5.2 and inject it for quantification by peak height. A6 Calculation
Where: X--the concentration of nitroglycerin in the air, mg/m. C,+C2
（、(2— are the contents of nitroglycerin in the front and rear GDX-103 desorption liquids, ug; V, are converted into the sampling volume under standard conditions, 1. A7 Explanation
（Al）
A7.1 The detection limit of this method is 1×10-4μg (injection of 1uL liquid sample). When the nitroglycerin content is 1.0, 2.5, 5.0, 10.0, 20.0μg/ml, the coefficient of variation is 5.75%, 4.24%, 3.20%, 2.86%, 2.69%, respectively. A7.2 The penetration capacity of this method is greater than 0.6mg. A7.3 The desorption efficiency using anhydrous ethanol as the desorbent is 96.65%~～104.18%. When the nitroglycerin concentration is When the concentration is 0.27~5.33mg/m, the sampling efficiency is 97.7%~100%. A7.4 After sampling, both ends of the sampling tube must be sealed to prevent contamination. It can usually be left at room temperature for 7 days. A7.5 Nitroglycerin is a high explosive. The sampling power must be explosion-proof. Standard products must be carefully handled and properly stored. Appendix B
Ethylenediamine Hydrochloride Colorimetric Method
(Supplement)
B1 Principle
After nitroglycerin is absorbed by ethanol, alkali is added for saponification. The nitrite in its aqueous solution reacts with p-aminobenzenesulfonic acid to undergo a diazotization reaction, and then couples with naphthylethylamine hydrochloride to produce a rose red color, which is quantitatively measured by colorimetry. B2 Instrument
B2.1 Porous glass plate absorption tube.
B2.2 Explosion-proof vacuum pump.
B2.3 Flow meter, 0~1L/min.
B2.4 Stoppered colorimetric tube, 25mL.
B2.5 Water bath.
B2.6 Spectrophotometer.
B3 Reagents
Absorption liquid: 95% (V/V) ethanol.
B3.2 Potassium hydroxide solution: 150g/L.
B3.3 Hydrochloric acid solution: 1+6.
B3.4 Color developer
GB 16212-1996
Liquid A: Weigh 5g of p-aminobenzenesulfonic acid, dissolve in 350mL of hydrochloric acid solution (B3.3), and dilute to 500mL with double distilled water. Liquid B: Weigh 0.5g of ethylenediamine hydrochloride, dissolve in 500ml of double distilled water, store in a brown bottle, and keep in the refrigerator for 1 month. Mix equal volumes of Liquid A and Liquid B before use. The solution should be colorless at this time, otherwise re-prepare. B3.5 Standard solution: Take 5-10ml of ethanol and put it into 50mL In a measuring bottle, weigh it on a balance, use a pipette to press the top with your index finger, insert the tip of the pipette through the water layer into the nitroglycerin layer, release your index finger, absorb a certain amount of nitroglycerin, take out the pipette, wipe off the liquid at the tip of the tube with filter paper, put 2 to 3 drops of nitroglycerin into the weighed measuring bottle, weigh it again, the difference between the two weighings is the weight of nitroglycerin, then dilute it with ethanol to the scale, calculate the micrograms of nitroglycerin per milliliter. Dilute it with ethanol to make a 1mL standard solution containing 10μg nitroglycerin before use.
B4 Sampling
Use a porous glass plate absorption tube containing 10mL of absorption liquid to extract 5L of air at a speed of 0.5L/min. B5 Analysis steps
B5.1 Control test: Same sampling, take the absorption tube with absorption liquid to the site, but do not extract air, and analyze it according to the sample. B5.2 Sample treatment: Take 5.0mL of sample absorption solution and put it into a 25mL colorimetric tube. B5.3
Drawing of standard curve: Take 7 25mL colorimetric tubes and prepare standard tubes according to Table B1. Table B1 Preparation of nitroglycerin standard tubes
Standard solution, ml
Nitroglycerin contains·ug
Add 0.5ml. Potassium hydroxide solution (B3.2) to the standard tube, put it in a 70℃ water bath for saponification for 15min, take it out and cool it to room temperature, then add 3ml. Color developer (B3.4) to each tube, and dilute it to the scale with double distilled water, shake it well, let it stand for 10min, and then use a 10mm colorimetric cup to perform colorimetric quantification at a wavelength of 540nm. Use the nitroglycerin content as the horizontal axis and the absorbance value as the vertical axis to draw a standard curve. B5.4 Determination: The sample tube is operated in the same way as the standard tube. After colorimetry, the nitroglycerin content is found on the standard curve. B6 Calculation
Where: X—nitroglycerin concentration in the air, mg/m\;——nitroglycerin content in the sample solution, pg; V. ——Sampling volume converted to standard conditions, L. B7 Explanation
(B1)bzxZ.net
B7.1 The detection limit of this method is 1μg/25mL. When the nitroglycerin content is 1, 2, 5, 10, 20, 30μg/25mL, the coefficient of variation is 7.8%, 6.4%, 4.2%, 1.8%, 1.6% and 1.7% respectively. B7.2 Two porous glass plate absorption tubes, each containing 10mL of absorption liquid, are connected in series. Samples are collected at a rate of 0.5L/min for 10min. When the concentration of nitroglycerin in the air is between 0.15 and 3.19mg/m2, the sampling efficiency of the front tube is 92.2%~100.0%, with an average of 98.4%. Therefore, it is not necessary to connect two absorption tubes in series for sampling.
B7.3 If NO2 coexists in the measured air, it will interfere with the determination. You can add 0.5ml of 50.0g/L ammonium sulfamate solution 463
in the colorimetric tube in advance to eliminate it.
GB16212—1996
B7.4 Nitroglycerin is a high explosive. In a workshop with nitroglycerin, it is forbidden to use non-explosion-proof electric vacuum pumps for sampling. Standard samples should be carefully operated and properly stored.
Additional instructions:
This standard is proposed by the Ministry of Health of the People's Republic of China. This standard was drafted by the Ordnance Industry Hygiene Research Institute. The main drafters of this standard are Feng Yangzheng and Zhang Huimin. This standard is interpreted by the Institute of Labor Hygiene and Occupational Diseases of the Chinese Academy of Preventive Medicine, the technical unit entrusted by the Ministry of Health.
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