GB 18557-2001 Occupational exposure limits for acephate in workplace air

This standard specifies the maximum permissible concentration and time-weighted average permissible concentration of acephate in workplace air and its monitoring and testing methods. This standard is applicable to all types of industrial enterprises that produce and use acephate. GB 18557-2001 Occupational exposure limits for acephate in workplace air GB18557-2001 Standard download decompression password: www.bzxz.net

GB18557—2001
This standard is formulated for the first time based on toxicological experiments, on-site labor hygiene surveys and occupational epidemiological survey data. It is a hygienic standard used for workplace environmental monitoring and health supervision: This standard shall be implemented from May 1, 2002. Appendix A of the standard is the appendix of the standard. This standard was proposed by the Ministry of Health of the People's Republic of China. The drafting units of this standard are: Institute of Hygiene, Zhejiang Academy of Medical Sciences, Shaoxing Municipal Health and Epidemic Prevention Station. The drafters of this standard are: Chen Xiufeng, Li Ren, Cao Wanjuan, Yu Yongkou. This standard is entrusted to the technical unit of Labor Hygiene and Occupational Disease Research, Chinese Academy of Preventive Medicine, for interpretation. 716
National Standard of the People's Republic of China
Oceupational exposure limit for acephate in the air of workplaceScope
GB 18557 2001
This standard specifies the maximum permissible concentration and time-weighted average permissible concentration of acephate in the air of workplace and its monitoring and inspection methods.
This standard is applicable to all types of industrial enterprises that produce and use acephate. 2 Hygiene requirements
The maximum permissible concentration of acephate in the air of workplace is 0.5mg/m3 (skin), and the time-weighted average permissible concentration is 0.3mg/m3 (skin).
3 Monitoring and inspection methods
The monitoring and inspection of this standard adopts gas chromatography, see Appendix A (Appendix to the standard). Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on December 4, 2001 and implemented on May 1, 2002
A1 Principle
GB 18557--2001
Appendix A
(Appendix to the subject matter)
Gas chromatographic determination of acephate in air After acephate in the air is adsorbed by a sampling tube filled with polyurethane foam plastic, it is separated by methanol desorption on a diethylene glycol adipate (DFGS) column and detected by a gas chromatograph equipped with a flame photometric detector. The retention time is used for qualitative analysis and the height is used for quantitative analysis. A2 Instruments
A2.1 Air sampler: flow rate (0~0.5)L/min and (01.0)L/min. A2.2 Colorimetric tube with stopper: 10 ml.
A2.3 Volumetric flask: 1 mL, 100 mL,
A2.4 Micro syringe: 1.0mL, 10.0l.A2.5 Sampling tube: Glass tube with inner diameter 6mm: 80Im long. Two sections of polyurethane foam plastics are placed inside, and sealed plastic sleeves are put on both ends. Prepare for on-site sampling. (Polyurethane foam plastic treatment: Use leather shoes to punch a 20mm thick foam plastic sheet into a cylinder with a diameter of 8mm and a length of 20mm, wash it with detergent, soak it in methanol overnight, and rinse it repeatedly with water. Bake it at 60-80 C for tube loading). A2.6 Gas chromatograph, flame photometer detector. Chromatographic column: 0.5m long, 3mm inner diameter glass column, filled with DEGS: Chromasorb W.AW-DMCS (80~100 months) -2: 100,
Temperature: 185C Detection chamber vaporization chamber temperature: 210C; Carrier gas (high purity nitrogen) flow rate: 70mL/min. Air: 0.75 kg/cm2. Hydrogen: 0.8 kg/cm*. A3 Reagents
A3.1 Methanol: AR.
A3.2 DEGS; Chromatographic stationary liquid,
A3.3 Chronasarh W.AW.DMCS 80~100 days Chromatographic carrier. A3.4 Acephate standard solution: Weigh (0.1010g) of acephate standard, dissolve it in methanol, transfer quantitatively to a 100 tI volumetric flask, and dilute to the mark. This solution is a 1.0mg/ml standard stock solution. Dilute it with methanol to a 100μg/ml acephate standard solution before use.
A4 Sampling
A4.1 Fixed-point sampling: At the sampling point, remove the plastic covers at both ends of the sample tube, let one end pass through the atmosphere, and connect the other end to the sampler (A2.1) to collect 30 L of water at a flow rate of 0.5L/min. Air sample A4.2 Individual sampling: At the sampling point, use the sampling tube and individual sampler (A2.1) to collect air at a flow rate of (.21./min) for (4~8) hours. After sampling, cover the sample with a sealed plastic cover and store and transport it away from light. A5 Analysis steps
A5.1 Control test: Bring the sampler to the sampling point. Except for not collecting air samples, the rest are the same as the sample as the blank Liu of the sample. A5.2 Sample treatment: Take out the polyurethane foam plastic in the sampling tube and put it in 10 mL stoppered colorimetric tube, add 2.0rmL of medium alcohol (A3.1), use a small glass rod to compress the plastic foam to make it completely submerged, vortex on the mixed product for 1min, leave it for 30min, and then measure: A5.3 Standard curve drawing: In 6 10mL container bottles (A2.3); prepare the standard series according to Table A1. 718
Standard solution (A3.4), mI
Methanol (A3.1}.mI.
Ethamidophos contains
GB 18557-.2001
Acephate Standard Series
Pipette 1μl of each bottle of standard solution and inject it into the chromatograph. Repeat 3 times for each concentration. Use the average value of the peak area (height) and the corresponding content to calculate the regression equation for quantitative calculation and retention time for qualitative calculation. A5.4 Sample determination: Use the operating conditions of the determination standard series to determine the sample and the methanol dilution of the blank control. Substitute the peak area (height) value of the sample into the regression equation to calculate Acephate content (g) A6 Calculationwww.bzxz.net
A6.1 According to formula (A1), the sampling volume is converted into the volume under standard conditions. 273
Ye=V×273++×101:3
In the formula, -
converted into the sampling volume under standard conditions, L; sample volume. L.;
the temperature at the sampling point,
the temperature at the sampling point, kPa.
A6. 2 Calculate the concentration of acephate in the air according to (A2). 2xm
Where: '
A7 Explanation
Liquidity of acephate in the air.mg/m'; Measured acephate content in the sample, g; Converted to sampling volume under standard conditions, 1.3 (Al)
【A2）
A7.1 The detection limit of this method is 7.8×10-g; The minimum detection concentration is 0.052mg/m (sampling volume 30 L, desorption volume 2ml). The measurement range is (0 ~15)/ml., and the relative standard deviation in this linear range is 2.3%~4.5%. A7.2 The sampling efficiency of this method is more than 99%, and the desorption efficiency is 85.8%~100.8%. A7. 3 At room temperature, the sample must be analyzed within 24 hours. A7.4 Under the present conditions, the raw material of acephate and other solvents do not interfere with the determination.
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