This standard specifies the maximum permissible concentration of dimethyl sulfate in the air of a workshop and its monitoring and testing methods. This standard is applicable to all types of enterprises that produce and use dimethyl sulfate. GB 16246-1996 Hygienic standard for dimethyl sulfate in the air of a workshop GB16246-1996 Standard download decompression password: www.bzxz.net

GB16246—1996
This standard is formulated for the first time based on toxicological experiments, on-site labor hygiene surveys and epidemiological surveys and with reference to foreign occupational exposure limit data. It is a hygienic 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 by the Ministry of Health of the People's Republic of China. The responsible drafting unit of this standard: Heilongjiang Provincial Labor Hygiene and Occupational Disease Research Institute. Participating drafting units: Qiqihar Labor Hygiene and Occupational Disease Prevention and Control Institute and Benxi Occupational Disease Prevention and Control Institute. The main drafters of this standard: Yang Yinsen, Ci Jieyuan, Liu Fuhuan, Zhang Jiaru, Zhang Huiquan. This standard is interpreted by the Institute of Labor Hygiene and Occupational Diseases, Chinese Academy of Preventive Medicine, the technical management unit entrusted by the Ministry of Health. 578
National Standard of the People's Republic of China
Health standard for dimethyl sulfatein the air of workplace
GB162461996
This standard specifies the maximum allowable concentration of dimethyl sulfate in the air of workplace and its monitoring and inspection methods. This standard is applicable to all types of enterprises that produce and use dimethyl sulfate. 2 Hygiene requirements
The maximum allowable concentration of dimethyl sulfate in the air of workplace is 0.5mg/m3 (skin). 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 State Administration of Technical Supervision on April 3, 1996, and implemented on September 1, 1996
A1 Principle
GB16246—1996
Appendix A
(Appendix to the standard)
Gas chromatography
Use a silicone tube to collect dimethyl sulfate (DMS) in the air. Use sodium nitrite to convert DMS into nitromethane at room temperature. Take the converted solution for injection, separate it on a GDX-102 chromatographic 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. A2 Instrument
A2.1 Silica gel sampling tube: Use a glass tube with a length of 80mm and an inner diameter of 3.5~4.0mm. The front section is filled with 100mg and the rear section is filled with 50mg. The silica gel of 40~60 mesh is filled. The two ends and the middle of the tube are plugged with polyurethane foam, and the two ends are covered with plastic caps. A2.2 Gas sampling pump: 0~1L/min.
A2.3 Syringe: micro syringe.
A2.4 Gas chromatograph, hydrogen flame ionization detector. The signal-to-noise ratio given by 1ng dimethyl sulfate is not less than 3:1. Chromatographic column: 2m long, 4mm inner diameter, stainless steel column. GDX-102 stationary phase. bZxz.net
Column temperature: 140℃.
Vaporization chamber temperature: 160℃.
Detection chamber temperature: 150℃.
Carrier gas (nitrogen): 120mL/min.
A3 Reagents
A3.1 Converter: 3% sodium nitrite aqueous solution. A3.2GDX-102 polymer porous bead chromatographic stationary phase, 40-60 mesh. A3.3DMS standard solution: Add 10mL of converter to a 25mL volumetric flask, weigh accurately, add 3 drops of DMS and weigh again, the difference between the two is the mass of DMS. Add the converter to the scale, calculate the DMS content in 1mL of solution, and dilute it with the converter to a standard application solution of 40~～200μg/ml before use (the solution can be stored for 1d at room temperature and 3d in the refrigerator). A4 Sampling
Remove the plastic caps at both ends of the sampling tube at the sampling site, place it vertically, and collect 10L of air at a rate of 0.5L/min. After sampling, put plastic caps on both ends of the tube and bring it back to the laboratory for analysis. A5 Analysis steps
A5.1 Control test: Same as sampling. Remove the plastic caps at both ends of the sampling tube at the site, but do not extract air. Store the sample and control tube separately, and record the temperature and air pressure at the site.
A5.2 Sample treatment: Pour the two sections of silica gel and foam into stoppered test tubes, add 0.5 mL of conversion agent, put it in room temperature for 1 hour after stoppering,
A5.3 Drawing of standard curve: Take 0.5 mL of standard solution with content of 40, 80, 120, 160200 g/mL into stoppered test tubes, add 100 mg of silica gel and two small pieces of foam plastics respectively, stopper, put it in room temperature (about 25°C) for 1 hour, take 5 μL injection, measure retention time and peak height. Repeat the measurement for 6 times for each concentration, take the mean peak height and plot it against the corresponding DMS content to draw the standard curve. A5.4 Determination
GB16246--1996
Under the same conditions as the standard curve determination, determine the sample and blank control, each with 5uL of sample; after subtracting the blank control absorbance value from the measured sample absorbance value, the DMS content (μg) is obtained from the standard curve. A6 Calculation
A6.1 Convert the sampling volume into the volume V under standard conditions according to formula (A1). V. =V×
The sampling volume under standard conditions, L;
Where: V-——
V----Sampling volume, L;
pThe atmospheric pressure of the sampling site, kPa;
The temperature of the sampling site, ℃.
A6.2 Calculate the concentration of DMS in the air according to formula (A2). Concentration of DMS in air, mg/m,
Where: c——1
273 + t
is the DMS content measured on the front and rear silica gel, μg, m1, m2
V. —Converted to the sampling volume under standard conditions, L. A7 Notes
A7.1 The detection limit of this method is 0.01μg/ml. A7.2 The collected DMS sample can be placed at room temperature for 7 days. 101.3
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