This standard specifies the maximum permissible concentration of acetic anhydride in the air of a workshop and its monitoring and testing methods. This standard applies to all types of industrial enterprises that produce and use acetic anhydride. GB 18550-2001 Occupational exposure limits for acetic anhydride in the air of a workshop GB18550-2001 Standard download decompression password: www.bzxz.net

GB18550—2001
This standard is formulated for the first time based on toxicological experiments, on-site labor hygiene surveys, epidemiological survey data and reference to foreign occupational exposure limits. It is a health standard used for workplace environmental monitoring and health supervision. Appendix A of this standard is the appendix of the standard.
This standard is proposed by the Ministry of Health of the People's Republic of China. The drafting units of this standard: Institute of Animal Health and Occupational Diseases, Chinese Academy of Preventive Medicine, Calcium Carbide Plant of Jilin Chemical Industry Company, and Staff Hospital of Jilin Chemical Industry Company
The main initiators of this standard: Ying Meiyuan, Ye Diqiu, Huang Xuexiang, Zhang Mingqi, Zhou Anshou. This standard is entrusted to the Institute of Labor Health and Occupational Diseases, Chinese Academy of Preventive Medicine for interpretation. 689
National Standard of the People's Republic of China
Occupational exposure limit for acetic anhydride in the air of workplace
Occupational exposure limit for acetic anhydride in the air of workplace
This standard specifies the maximum permissible concentration of acetic anhydride in the air of workplace and its monitoring and inspection methods. This standard applies to all kinds of industrial enterprises that produce and use acetic anhydride. 2 Hygiene requirements
The maximum permissible concentration of acetic anhydride in the air of the workshop is 16mg/m3. 3 Monitoring and inspection methods
The monitoring and inspection methods of this standard adopt gas chromatography, see Appendix A (Appendix to the standard). Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on December 4, 2001690
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GB 18550—2001
2002-05-01 Selling and applying
A1 Principle
GB 18550-2001
Appendix A
(Appendix to the standard)
Determination method of acetic anhydride in the air of the workshop by solvent desorption gas chromatography The acetic anhydride in the air is collected by activated carbon tube, desorbed by ketone, separated by Tenax chromatographic column, and detected by hydrogen flame ionization detector. The retention time is used for qualitative analysis and the peak height is used for quantitative analysis.
A2 Instruments
A2. 1 Activated carbon tube; a glass tube with a length of 120 mm and an inner diameter of 3.5 mm is divided into two sections and filled with 100 mg and 50 m activated carbon respectively. A small amount of glass wool is used to separate the middle and fix the two ends with a small amount of glass wool. After the tube is filled, it is heated to 300℃ under nitrogen, kept for 10 min, and sealed for storage.
A2.2 Solvent desorption bottle: 5ml.
A2.3 Micro syringe: 10μL.
A2.4 Air sampler: (0~3)1/min.bzxz.net
A2.5 Gas chromatograph, hydrogen flame ionization detector. Chromatographic column, column length 2m, inner diameter 2.5mm glass column. Tenax: (60~80) days
Column temperature: 135℃.
Vaporization chamber temperature: 200℃.
Detection chamber temperature: 200℃.
Carrier gas (ammonia): 35 mL/min.
A3 Reagents
A3. 1 Activated carbon: GH-1, (20~40) mesh. A3.2 Acetone: analytical grade.
A3.3 Tenax: (60~80) mesh.
A3.4 Standard solution: Add a small amount of acetone to a 10mL volumetric flask, weigh accurately, add 2~3 drops of acetic anhydride, weigh accurately again, the difference between the two is the amount of acetic anhydride weighed, add acetone to dilute to the scale, calculate the acetic anhydride content per mL of solution, and then dilute to 1mL of acetic anhydride standard solution containing 1.0mg.
A4 Sampling
Before sampling, open the activated carbon tube. Connect the 50mg end to the sampler, extract 6L of air at a flow rate of 0.2L/min, and quickly cover both ends with plastic caps.
A5 Analysis steps
A5.1 Control experiment: Bring the activated carbon tube to the sampling point. Except for not collecting air, the rest of the operations are the same as the sample, as a blank control of the sample. A5.2 Sample treatment: After sampling, put the two sections of activated carbon into the solvent desorption bottle respectively, add 2ml of ketone to each. After plugging, shake from time to time. Desorb for 30min.
A5.3 Drawing of standard curve: Take the standard solution and dilute it with acetone to prepare 10.8, 21.6, 54.0, 108, 541g/mL acetic anhydride standard series, adjust the instrument to the best state according to the measurement conditions, inject 2L, measure each concentration 3 times, calculate the average of the peak height, use the average of the peak height as the vertical axis, and the concentration of acetic anhydride (μg/ml) as the horizontal axis to draw the standard curve. A5.4 Determination: Under the same conditions as the standard curve determination, measure the sample and the blank control, and subtract the blank control peak height from the measured sample peak height to obtain the concentration of acetic anhydride (μg/ml) from the standard curve. A6 Calculation
A6.1 Convert the sample volume into the volume under standard conditions according to formula (A1). Va=V×#
273 + t
Wherein, V.
is converted into the sampling volume under standard conditions, L; V
sampling volume, L
atmospheric pressure at the sampling site, kPa;
the temperature at the sampling site,.
A6.2 Calculate the concentration of acetic anhydride in the air according to formula (A2): 101.3
(ci +c2) × V
Wherein:
-the concentration of acetic anhydride in the air, mg/m
cic2, the concentration of acetic anhydride in the front and rear sections can be obtained from the standard curve, g/mL: V—the volume of the sample liquid obtained after sample treatment, mL. A7 Description
(A2)
A7.1 The detection limit of this method is 1.2×10*g (2μL injection), the minimum detection concentration is 2mg/m (6L air sampling), the linear range is (10.8~541)μg/mL, and the relative standard deviation is 1.4%~5.3%. A7.2 The sampling efficiency of this method is 100%, the penetration capacity is greater than 4 mg, and the desorption efficiency is greater than 90%. A7.3 The loss of acetic anhydride collected by activated carbon is less than 5% when sealed and stored at room temperature for 1 week. A7.4 Methyl acetate, formic acid, acetic acid, and acetaldehyde do not interfere with the determination. 692
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