This standard specifies the maximum permissible concentration of perchloroethylene in workshop air and its monitoring and testing methods. This standard applies to all types of enterprises that produce and use perchloroethylene. GB 16204-1996 Hygienic Standard for Perchloroethylene in Workshop Air GB16204-1996 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Health standard for tetrachloroethylene in the air of workplace
Health standard for tetrachloroethylene in the air of workplace Subject content and scope of application
This standard specifies the maximum allowable concentration of tetrachloroethylene in the air of workplace and its monitoring and inspection methods. This standard applies to all types of enterprises that produce and use tetrachloroethylene. 2 Hygiene requirements
The maximum allowable concentration of tetrachloroethylene in the air of workplace is 200mg/m2 3 Monitoring and inspection methods
The monitoring and inspection methods of this standard adopt gas chromatography, see Appendix A (supplement). 4 Supervision and implementation
Health supervision agencies at all levels are responsible for the implementation of this standard. Approved by the State Administration of Technical Supervision on April 3, 1996 138 www.bzxz.net
GB 16204—1996
Implementation on September 1, 1996
A1 Principle
GB 16204-1996
Appendix A
Gas chromatography
(Supplement)
A1.1 Use an activated carbon tube to collect tetrachloroethylene in the air, inject it after thermal desorption, separate it on a polyethylene glycol 6000 column, and detect it with a hydrogen flame ionization detector. The retention time is used for qualitative analysis and the peak height is used for quantitative analysis. A1.2 The detection limit of this method is 1.8×10-\μg (directly inject 1mL of desorbed gas sample). A2 Instruments
A2.1 Activated carbon tube: Use a glass tube with a length of 200mm, an inner diameter of 3.5~4.0mm, and an outer diameter of 6mm, and load it with 100mg 20~40 mesh coconut shell activated carbon, and fix both ends with a small amount of silanized glass wool. Before loading the tube, first treat the activated carbon with nitrogen at about 300℃ for 3~4h. After loading the tube, blow it with nitrogen at the same temperature for 2~3min. For short-term use, put plastic caps on both ends for storage. For long-term use, seal the two ends with fire for storage.
A2.2 Sampling pump, 0~~1L/min.
A2.3 Syringe: 100mL, 5mL, 1mL, 1μL. A2.4 Thermal desorption device: The thermal desorption device mainly consists of an electric heater, a temperature controller, a temperature gauge and a gas flow controller. The flow control range is 50100mL/min. The structure of the thermal desorption device used should make it easy to insert the activated carbon tube into the heater, and preheat the gas passing through the tube so that the activated carbon is heated evenly. A2.5 Gas chromatograph: hydrogen flame ionization detector. A3 Reagents
A3.1 Tetrachloroethylene, analytical grade.
A3.2 Polyethylene glycol 6000, chromatographic stationary liquid. A3.36201 Red support, 60-80 mesh. A3.4 Anhydrous methanol, analytical grade.
A3.5 Chlorodimethylsilane, analytical grade.
A4 Sampling
Open the activated carbon tube at the sampling site, with the aperture of at least 2mm at both ends, place it vertically, and extract 1-2L of air at a rate of 0.2-0.5L/min. After sampling, put plastic caps on both ends of the tube and analyze as soon as possible. A5 Analysis steps
A5.1 Chromatographic conditions
Chromatographic column: 2m long, 3mm inner diameter glass column, polyethylene glycol 6000:6201 red carrier = 5:100, a.
Column temperature: 90℃;
Vaporization chamber temperature: 150℃;
Detection chamber temperature: 150℃;
Carrier gas (nitrogen): 60mL/min.
A5.2 Standard curve drawing
Use a micro syringe to accurately measure a certain amount of tetrachloroethylene (at 20℃, the mass of 1uL tetrachloroethylene is 1.6227mg) and inject it into a 100ml syringe to prepare standard gases of 0.175, 0.350.0.700, and 1.75μg/mL, take 1mL of sample respectively, and measure the peak height and retention time. Repeat 3 times for each 439
GB16204-1996
concentration, take the average value of the peak height, plot the peak height against the content of tetrachloroethylene, and draw a standard curve. Retention time is a qualitative indicator.
A5.3 Sample analysis
A5.3.1 Control test: Bring the activated carbon tube to the site and bring it back to the laboratory with the sample, analyze it according to the sample, and use it as a blank control. A5.3.2 Sample treatment: Connect the gas inlet of the sample tube to a 100mL syringe, place it on a thermal desorption device, and desorb it at 250℃ with nitrogen at a rate of 50-60mL/min. The desorbed gas volume is 100mL. A5.3.3 Determination:
Take 1ml of desorbed gas for injection, use retention time for qualitative analysis and peak height for quantitative analysis. The chromatogram is shown in Figure A1. min
Figure A1 Chromatogram of tetrachloroethylene
A6 Calculation
Wherein, X-concentration of tetrachloroethylene in air, mg/m\; C-concentration of tetrachloroethylene obtained from the standard curve, μg/mL; V. --Converted into the sampling volume under standard conditions, L. A7 Notes
A7.1 When the concentration of tetrachloroethylene is 0.175, 0.3500.700, and 1.75μg/mL, the coefficient of variation is 4.1%, 4.5%, 2.8%, and 2.1%, respectively. The penetration capacity of the 100mg activated carbon tube test is greater than 43mg. A7.2 The activated carbon tube absorbs almost all organic vapors. After sampling, both ends should be immediately covered with plastic caps to prevent contamination. No sample loss was observed after 14 days of storage at room temperature. Generally, it should be analyzed as soon as possible. A7.3 When applying the thermal desorption method, the desorption efficiency must be tested first. It can only be applied when the desorption efficiency is above 75%. The desorption efficiency of this study is 87.5%~~94.4%.
Additional Notes:
GB16204—1996
This standard is proposed by the Ministry of Health of the People's Republic of China. This standard is drafted by the Beijing Institute of Labor Hygiene and Occupational Disease Prevention and Control, and is jointly drafted by the Beijing Haidian District Health and Epidemic Prevention Station. The main drafter of this standard is Dai Riying.
This standard is interpreted by the Institute of Labor Hygiene and Occupational Diseases, Chinese Academy of Preventive Medicine, which is the technical unit entrusted by the Ministry of Health.
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