This standard specifies the maximum permissible concentration and time-weighted average permissible concentration of cortisone in workplace air and its monitoring and inspection methods. This standard is applicable to all types of enterprises that produce and use cortisone. GB 16250-1996 Hygienic Standard for Cortisone in Workshop Air GB16250-1996 Standard download decompression password: www.bzxz.net

GB16250—1996
This standard is formulated for the first time based on toxicological experiments, on-site labor hygiene surveys, and epidemiological survey data. It is a health standard used for workplace environmental monitoring and health supervision. This standard shall be implemented from September 1, 1996. Appendix A of this standard is the appendix of the standard. This standard is proposed and managed by the Ministry of Health of the People's Republic of China. The drafting unit of this standard is Tianjin Institute of Labor Hygiene and Occupational Diseases. The main drafters of this standard are Xu Jia, Mi Yaxian, Yang Yourun, Chen Suping, and Zhang Gang. This standard is interpreted by the Institute of Labor Hygiene and Occupational Diseases, Chinese Academy of Preventive Medicine, which is the technical management unit entrusted by the Ministry of Health. 598
National Standard of the People's Republic of China
Health standard for cortisone in the air of workplace
Health standard for cortisone in the air of workplaceGB16250-1996
This standard specifies the maximum permissible concentration and time-weighted average permissible concentration of cortisone in the air of workplaces and their monitoring and inspection methods. This standard applies to all types of enterprises that produce and use cortisone. 2 Hygiene requirements
The maximum allowable concentration of cortisone in the air of the workshop is 3 mg/m3; the time-weighted average allowable concentration is 1 mg/m2. 3 Monitoring and inspection methods
The monitoring and inspection methods of this standard adopt high-pressure liquid chromatography, see Appendix A. Approved by the State Bureau of Technical Supervision on April 3, 1996 and implemented on September 1, 1996
A1 Principle
GB 16250--1996
Appendix A
(Appendix to the standard)
Determination of cortisone in the air of the workshop by high-pressure liquid chromatography Use perchloroethylene filter membrane to collect cortisone dust and smoke, elute with methanol, separate on a C1: liquid chromatography column, and detect with an ultraviolet detector. The retention time is used for qualitative analysis and the peak height is used for quantitative analysis. A2 Instruments
A2.1 Perchloroethylene filter ($37mm): soak in anhydrous methanol for 30 minutes before use, dry in clean air and place in a dryer for later use. A2.2 Sampling pump: 0~1.5L/min, 0~30L/min. A2.3 Stoppered test tube, 5mL.
A2.4 Liquid rapid mixer.
A2.5 High pressure liquid chromatograph, UV detector. Chromatographic column: 25mm long, 4.6mm inner diameter, stainless steel column. Column packing: Cr (5 μm).
Column temperature: 55℃.
Mobile phase: methanol + water = 7 + 3.
Flow rate: 1.0mL/min.
UV detector wavelength: 240nm.
A3 Reagents
A3.1 Anhydrous methanol, analytical grade.
A3.2 Cortisone: purity is 99.90%.
A3.3 Cortisone standard solution: accurately weigh 5 mg of cortisone, dissolve it with a small amount of anhydrous methanol, transfer it quantitatively to a 10 mL volumetric flask, and dilute it to the mark to prepare 1 mL of 500 μg of cortisone stock solution. Then take an appropriate amount of this stock solution and dilute it with anhydrous methanol to 1 mL = 10 μg 30 u μg and 50 μg of cortisone standard solution. A4 Sampling
Install the filter membrane in the sampling clip at the sampling site. Due to different production process flows, cortisone can exist in different states in the air. When it exists in the smoke state, 45 L of air is extracted at a rate of 1.5 L/min; when it exists in the dust state, 1001 air is extracted at a rate of 10 L/min.
A5 Analysis steps
A5.1 Control test: Bring the filter membrane to the site, except that no air sample is collected, operate the same as the sample as a blank control. A5.2 Sample processing: Bring the sampled filter membrane back to the laboratory, place it in a test tube, add 2mL of anhydrous methanol, soak for 30min, and then vortex on a liquid rapid mixer for 1min before analysis. A5.3 Drawing of standard curve: Use a microsyringe to inject 1μL of 0, 10, 30, and 50ug/mL cortisone standard solution, repeat each concentration 3 times, take the average peak height, and plot the cortisone content (μg) against the peak height (μV) to draw a standard curve, with retention time as a qualitative indicator.
A5.4 Determination: Take 1.0ul. of the sample supernatant for analysis, and use retention time for qualitative analysis and peak height for quantitative analysis. The cortisone content in the sample can be obtained from the standard curve.
A6 Calculation
GB162501996
A6.1 Convert the volume of the sample into the volume under standard conditions according to formula (A1): V. =V×
Wherein: Vo-
Volume under standard conditions, L;
273 + t
Volume of air sampled when the temperature at the sampling site is tC, L; p-atmospheric pressure at the sampling site, kPa;
Temperature at the sampling site, ℃.
A6.2 Calculate the concentration of chlorpyrifos in the air according to formula (A2): X
Wherein: X-Concentration of chlorpyrifos in the air, mg/m; CThe chlorpyrifos content is found from the standard curve, ug; V. -Sampling volume under standard conditions, L. A7 Description
·（A1）
（A2）
A7.1 The detection limit of this method is 0.3μg/mL. When the concentration of cortisone is 10μg/mL, 30ug/mL and 50μg/mL, the coefficient of variation is 3.5%, 2.1% and 3.2% respectively. bzxZ.net
A7.2 After cortisone is collected by perchloroethylene filter membrane and eluted with methanol, the average elution efficiency is 94.0% and the sampling efficiency is 97.6%. 601
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