GB 16188-1996 Hygienic standard for omethoate in workshop air

This standard specifies the maximum permissible concentration of omethoate and its monitoring and testing methods. This standard applies to all types of enterprises that produce and use omethoate. GB 16188-1996 Hygiene standard for omethoate in workshop air GB16188-1996 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Health standard for oletkowte in the air of workplace
Health standard for oletkowte in the air of workplace1 Subject content and scope of application
This standard specifies the maximum permissible concentration of oletkowte and its blue test method. This standard applies to all types of enterprises that produce and use oletkowte. Hygiene requirements
The maximum permissible concentration of oletkowte in the air of workplace is 0.3mg/m3 (skin). 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 Technical Supervision Commission on April 3, 1996 394
GB16188-1996
Implementation on September 1, 1996
A1 Principle
GB16188-1996
Appendix A
Gas chromatography
(Supplement)
Use a silicone tube to collect omethoate in the air, desorb it with acetone, and separate it on a glycol polyester column. Then use a flame photometer to detect the substance. The retention time is used for qualitative analysis and the peak height is used for quantitative analysis. A2 Instruments
A2.1 Silicone tube: Use a silanized glass tube with a length of 250mm, an inner diameter of 3.5-40mm, and an outer diameter of about 6mm. Fill the tube with 20-40 mesh silica gel in two sections, 300mg in the front section and 50mg in the back section. Separate the middle section with 1mm silanized glass wool and fix the two ends with 2mm silanized glass wool. After the tube is installed, blow nitrogen at 200℃ for 2-3min. For short-term use, cover the two ends with silicone rubber sheets and then put on plastic caps for storage. For long-term use, seal the two ends with fire.
A2.2 Sampling pump, 0-1L/min.
A2.3 Syringe, 10 μL, 1 μL.
A2.4 Centrifuge tube with stopper, 10 mL.
A2.5 Gas chromatograph with flame photometric detector and 526nm phosphorus filter. Chromatographic column: 2m long, 3mm inner diameter glass column. Stationary phase: EGA: Chromosorb W-AW, DMCS=5::100. Column temperature: 140℃. Www.bzxZ.net
Vaporization chamber temperature: 170℃.
Detection chamber temperature: 170℃.
Carrier gas (nitrogen): 70mL/min.
A3 Reagents
A3.1 Silica gel: Crush the primary silica gel, sieve, select 20-40 mesh silica gel and put it into a beaker, add 1+1 sulfuric acid-nitric acid mixed acid, the amount of acid added exceeds the silica gel surface by 1-2cm, put it in a boiling water bath and boil for 4h, discard the acid layer after cooling, wash the acid solution with tap water, and then wash it with distilled water several times until there is no sulfate ion, dry the washed silica gel at 100℃, and activate it at 250℃ for 4h. A3.2 Silanized glass wool: Clean the glass wool with the method of cleaning glass instruments, dry it, and then silanize the glass wool with 5% dichlorodimethylsilane solution for 2 hours, pour out the residual liquid, wash the residual liquid with anhydrous methanol, and dry it for later use. A3.3 Dichlorodimethylsilane solution: 5% (V/V), 5mL dichlorodimethylsilane is diluted with 100mL of anhydrous methanol. A3.4 Stationary liquid: Ethylene glycol adipate (EGA), chromatographic stationary liquid. A3.5 Support: Chromosorb W-AW, DMCS80~10o mesh. A3.6 Acetone: analytical grade.
A4 Sampling
Open the silicone tube at the sampling site, with the aperture of at least 2mm at both ends, place it vertically, and extract 3L of air at a speed of 0.2~0.5L/min. After sampling, cover the two ends of the tube with silicone rubber sheets, then put on plastic caps, store at a low temperature of 0~5℃, and analyze as soon as possible. A5 Analysis steps
A5.1 Control test
GB 16188—1996
Bring the silicone tube to the site and bring it back to the laboratory together with the sample. Analyze it according to the sample as a blank control. A5.2 Sample processing
Pour the front glass wool and silica gel and the back silica gel into two centrifuge tubes containing 2mL acetone respectively, cover with ground stoppers, shake vigorously for 100 times, soak for 30 minutes, take 1μL acetone solution for injection, use retention time for qualitative analysis and peak height for quantitative analysis. A5.3 Drawing of standard curve
In a 25mL brown volumetric flask, first add a small amount of acetone solution, weigh accurately, then add 1 to 2 drops of omethoate, and weigh accurately again. The difference between the two weights is the weight of omethoate. Dilute with acetone to the scale. This solution is the stock solution. Before use, dilute with acetone to make standard solutions of 1.5, 7.5, and 15μg/mL. Take 1uL for injection, use gas chromatography flame photometric detector, 526nm filter plate to measure retention time and peak height, repeat 3 times for each concentration, take the average peak height, plot omethoate content against peak height, draw a standard curve, and use retention time as a qualitative indicator.
A5.4 Determination
Take 1ul. acetone desorption solution for injection, use retention time for qualitative analysis and peak height for quantitative analysis. See Figure A1 for the chromatogram. tl,
Time. min
Chromatographic separation diagram
Figure Al1
A6 Calculation
X=×2 000
Where: X—
Concentration of omethoate in air, mg/m;
is the content of omethoate in acetone solution of the front section and the back section of silica gel, g, Ci.C2
V. Sample volume under standard conditions, L.
A7 Explanation
A7.1 The detection limit of this method is 2.5×10-μg. The coefficient of variation of the standard curve is 3.1%~3.9%. (A1)
A7.2 When the relative humidity is below 85%, the sample is collected at a speed of 0.5L/min for 4h using a plastic bag with gas distribution, and the penetration test is carried out. The content in the front section reaches 2mg, and no sample is detected in the back section. The adsorption amount of omethoate by silica gel can meet the on-site hygiene requirements. A7.3 Under the experimental conditions of this method, the desorption efficiency of omethoate reaches 94%. The sample is stored at 0℃~~5℃ for 14 days, and no sample loss is observed.
A7.4 The chromatogram can separate the coexisting dimethyl phosphite, methyl chloroacetate, toluene and trichloromethane, and the intermediate of methyl thiophosphate has not been separated. However, the two poisons on site are not produced at the same location, so the column can be used. 396
GB16188—1996
A7.5 The small impact bottle sampling of toluene solution and the silica gel sampling have been compared in the laboratory and on site. The results show that there is no difference in the concentration of the two sampling methods, indicating that silica gel sampling is reliable. 200 samples were collected from a pesticide factory, and no samples were detected in the latter part. Silicone tubes are easy to absorb water, so they must be installed according to the regulations before use, and prevent silicone tubes from being contaminated on site. A7.6
Additional instructions:
This standard was proposed by the Ministry of Health of the People's Republic of China. This standard was drafted by the Beijing Institute of Labor Hygiene and Occupational Disease Prevention and Control and the School of Public Health of Shanghai Medical University. The main drafters of this standard are Ji Yunjing, Gu Zuwei, and Pei Shu. This standard is interpreted by the Institute of Labor Hygiene and Occupational Diseases of the Chinese Academy of Preventive Medicine, which is the technical management unit entrusted by the Ministry of Health. 3
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