GB 8780-1988 Hygienic standard for dimethylacetamide in workshop air

This standard applies to all types of enterprises that produce and use dimethylacetamide. GB 8780-1988 Hygienic standard for dimethylacetamide in workshop air GB8780-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Hyglenic standard for dimethylacetamide in the air or workplace
This standard applies to all types of enterprises that produce and use dimethylacetamide. 1 Hygienic requirements
The maximum allowable concentration of dimethylacetamide in the air is 10 mg/m(skin). 2 Monitoring and inspection methods
The monitoring and inspection methods of this standard adopt gas chromatography, see Appendix A. Approved by the Ministry of Health of the People's Republic of China on February 23, 1988 UDC661.92.013
.8:628.512
GB 8780-88
Implementation on December 1, 1988
A.1 Principle
GB 87B0
Appendix A
Gas chromatography
(Supplement)
Dimethylethylamine in air is separated by polyethylene glycol 20000 and potassium hydroxide chromatographic columns and detected by hydrogen flame ionization detector. The retention time is used for qualitative analysis and the peak height is used for quantitative analysis. The detection limit of this method is 5×10- (injection of 5μl liquid sample). A.2 Apparatus
A.2. 1 Syringe: 100 ml, 1ml.
A. 2.2 Microsyringe: 10 μl.
A.2.3 Gas chromatograph: hydrogen flame ionization detector. A.3 ReagentswwW.bzxz.Net
A. 3.1—Methylacetamide: chromatographic grade,
A.3.2 Polyethylene glycol 20000: chromatographic stationary liquid. A.3.3 Potassium hydroxide.
A.3.4 6201 Support: 60~80 days.
A.4 Fruit sample
Use a porous glass plate absorption tube containing 5 ml of water to extract 10~20 L of air at a speed of 1 L/min. A. 5 Analysis steps
A.5.1 Chromatographic conditions
A,5. 1. 1 Chromatographic column: 2 m long, 4 mm inner diameter, stainless steel column. A.5.1.2 Polyethylene glycol 20000 Potassium hydroxide 6201 → 5 5:100. A.5.1.3 Column temperature: 120.
A.5.1.4 Vaporization chamber temperature: 200C.
A.5.1.5 Detection chamber temperature 150℃.
A.5.1.6 Carrier gas (ammonia): 30ml/mn. A.5.2 Drawing of standard curve
Prepare with water and dilute appropriately to 1ml standard solution containing 0.0250.050.0.075mg dimethylacetamide. Inject 5ul, measure retention time and peak height, repeat 3 times for each degree, and take the average peak height. Plot the peak quotient against the content of dimethylacetamide and draw the standard curve. Retention time is a qualitative indicator. A.5.3 Chromatogram
:comA.5.4 Sample analysis
GB 8780-88
Methyl acetamide
liMethyl acetamide
Time, min
Take 5 μ sample injection, use retention time for qualitative analysis and peak height for quantitative analysis. A.5.5 Calculation
Where: x-concentration of dimethylacetamide in air, mg/mC-content of dimethylacetamide found on the standard curve; V,-converted sampling volume under standard conditions, L. Note: When the concentration of dimethylacetamide is 0.15, 0.3, and 0.6 ug, the coefficient of variation is 4.7%, 3.7%, and 3. 4% respectively. Additional notes:
This standard is proposed by the Labor Hygiene Standard Subcommittee of the National Health Standard Technical Committee. This standard was drafted by Shanghai Labor Hygiene and Occupational Diseases Research Institute. The main author of this standard is Fu Weizu. This standard is interpreted by the Labor Hygiene and Occupational Diseases Research Institute of the Chinese Academy of Preventive Medicine, the technical unit entrusted by the Ministry of Health.
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