This standard specifies the maximum permissible concentration of naphthalene in the air of a workplace and the monitoring method. This standard applies to all types of enterprises that produce and use naphthalene. GB 16185-1996 Hygienic Standard for Naphthalene in Workshop Air GB16185-1996 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Health standard for naphthalene in the air of workplace
1 Subject content and scope of application
This standard specifies the maximum permissible concentration and monitoring method in the air of workplaces. This standard applies to all types of enterprises that produce and use naphthalene. Hygiene requirements
The maximum permissible concentration of naphthalene in the air of workplaces is 50mg/m2.3 Monitoring and inspection methods
The monitoring and inspection methods of this standard adopt gas chromatography, see Appendix A. 4 Supervision and implementation
Health and epidemic prevention agencies at all levels are responsible for supervising the implementation of this standard. Approved by the State Administration of Technical Supervision on April 3, 1996, GB16185-1996
Implementation on September 1, 1996
A1 Principle
GB16185-1996
Appendix A
Gas chromatography
(Supplement)
Use activated carbon tube to collect naphthalene in the air, desorb it with carbon disulfide, inject a certain amount of desorbed sample into the gas chromatograph, separate it with OV-101 column, and detect it with hydrogen flame ionization detector. Retention time is qualitative, peak height is quantitative. The detection limit of this method is 4×10-*μg (injection 5μl. liquid sample). A2 Instruments
A2.1 Activated carbon tube: glass tube sealed at both ends, inner diameter 4mm, outer diameter 6mm, length 7cm, filled with 2040 mesh activated carbon (made of coconut shell, activated at 600℃ before use), separated by 2mm foam plastic in the middle, 100mg at the front end, 50mg at the back end, 3mm foam plastic fixed at the front and back, and a silanized glass wool in front of the front end. When the sampling speed is 1L/min, the pressure drop in the tube must be less than 3.33 kPa.
A2.2 Atmospheric sampler, 0～1.5L/min. A2.3 Stoppered test tube, 2ml.
A2.4 Micro syringe, 10μl.
A2.5 Gas chromatograph, hydrogen flame ionization detector. A3 Reagents
A3.1 Naphthalene, chromatographic grade.
A3.2 Carbon disulfide, analytical grade.
A3.3OV-101, chromatographic stationary liquid.
A3.4Chromosorb WAW-DMCS support, 80~100 mesh. A4Sampling
Open the activated carbon tube at the sampling site, connect the rear end to the atmospheric sampler, and place it vertically to extract 30L of air at a rate of 1L/min. After sampling, the activated carbon tube is plugged with a plastic cap. There should be a blank tube for every 10 samples. A5Analysis steps
A5.1Chromatographic conditions
Chromatographic column: 2m long, 3mm inner diameter stainless steel column. a.
OV-101 : Chromosorb W AW-DMCS support-10 : 100. b.Vaporization chamber temperature: 200℃.
c. Detection chamber temperature: 200℃.
d. Column temperature: 170℃.
e: Carrier gas (nitrogen): 40mL/min.
A5.2 Standard curve drawing
Take an appropriate amount of naphthalene and prepare a 400mg/mL standard solution with carbon disulfide, then dilute it to 0.4, 0.8, 1.6, 2.4, 3.2mg/mL; take 5μl, inject, repeat each concentration 3 times, take the average value of the peak height, and draw a standard curve by plotting the concentration against the peak height. Retention time is a qualitative indicator.
A5.3 Sample analysis
GB16185-1996
In the laboratory, remove the glass wool in the activated carbon, transfer the front and rear activated carbon into two 2mL stoppered test tubes, add 1mL of carbon disulfide to each, shake from time to time, desorb for 30min, add the desorption volume to 1mL, and take 5μL for injection. Use retention time for qualitative analysis and peak height for quantitative analysis.
A6 Calculate
the concentration of naphthalene in the air, mg/m2;
where: X
×1000
Ci, C2—the concentration of activated carbon desorption solution in the front section and the back section, mg/mLV. —the sampling volume under standard conditions, L; D—desorption efficiency, %.
A7 Precautions
·(AI)
A7.1 In order to eliminate the influence of carbon disulfide backblowing or evaporation in the syringe, the standard and sample are injected by solvent flushing injection technology.
A7.2 The sampling volume of this method is affected by the amount that activated carbon can adsorb. If the amount of sample adsorbed in the back section of the activated carbon tube exceeds 25% of the front section, the sample has penetrated. www.bzxz.net
A7.3 After the activated carbon tube collects naphthalene in the air, it should be analyzed as soon as possible. If it cannot be analyzed on the same day, it should be stored in the refrigerator. Additional Notes:
This standard was proposed by the Ministry of Health of the People's Republic of China. This standard was drafted by Anhui Medical University, and was drafted in collaboration with the Nanjing Health and Epidemic Prevention Station, the Occupational Disease Prevention and Control Institute of Ma'anshan Iron and Steel Company, and the Health and Epidemic Prevention Station of Shanghai Meishan Metallurgical Company. The main drafter of this standard was Wang Zongyue.
This standard was 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. 387
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