|
US$139.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email.
GBZT300.164-2018: Determination of toxic substances in workplace air -- Part 164: Diphenylmethane diisocyanate
Status: Valid
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivered in | Standard Title (Description) | Status | PDF |
| GBZ/T 300.164-2018 | English | 139 |
Add to Cart
|
3 days [Need to translate]
|
Determination of toxic substances in workplace air -- Part 164: Diphenylmethane diisocyanate
| Valid |
GBZ/T 300.164-2018
|
PDF similar to GBZT300.164-2018
Basic data | Standard ID | GBZ/T 300.164-2018 (GBZ/T300.164-2018) | | Description (Translated English) | Determination of toxic substances in workplace air -- Part 164: Diphenylmethane diisocyanate | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | C60 | | Word Count Estimation | 7,749 | | Date of Issue | 2018-07-16 | | Date of Implementation | 2019-07-01 | | Regulation (derived from) | State-Health-Communication (2018) No.13 | | Issuing agency(ies) | National Health and Family Planning Commission | GBZ/T 300.164-2018: Determination of toxic substances in workplace air -- Part 164: Diphenylmethane diisocyanate
---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Determination of toxic substances in workplace air - Part 164. Diphenylmethane diisocyanate
ICS 13.100
C 52
National Occupational Health Standards
Determination of toxic substances in workplace air
Part 164. Diphenylmethane diisocyanate
Determination of toxic substances in workplace air-
Part 164. Diphenylmethane diisocyanate
Published on.2018-07-16
2019-07-01 implementation
National Health and Wellness Committee of the People's Republic of China
Foreword
This part is the 164th part of GBZ /T 300 "Measurement of Toxic Substances in Workplace Air".
This part is drafted in accordance with the rules given in GB/T 1.1-2009.
This section is mainly drafted by. Shanghai Chemical Occupational Disease Prevention and Treatment Institute, Shanghai Osa Evaluation Consulting Co., Ltd., Osavi, Anhui Province
Health Testing Technology Co., Ltd.
The main drafters of this section. Wang Zubing, Wang Xiaobing, Wang Xiang, Liu Yuming, Zhang Jun, Liu Wei, Bai Yunfei, Lu Yi-.
Determination of toxic substances in workplace air
Part 164. Diphenylmethane diisocyanate
1 Scope
This part of GBZ /T 300 specifies the collection of impregnated filter paper for the determination of diphenylmethane diisocyanate (MDI) in the workplace air -
High performance liquid chromatography.
This standard applies to the detection of the concentration of diphenylmethane diisocyanate in the workplace air.
2 Normative references
The following documents are indispensable for the application of this document. For dated references, only the dated version applies to this document.
For undated references, the latest edition (including all amendments) applies to this document.
GB/T 6682 Analytical laboratory water specifications and test methods
GBZ 159 Sampling specification for monitoring of hazardous substances in the workplace air
Basic information on 3 diphenylmethane diisocyanate
The basic information of diphenylmethane diisocyanate is shown in Table 1.
Table 1 Basic information of diphenylmethane diisocyanate
Chemical material
Chemical Abstracts
(CAS number)
Molecular formula relative molecular mass
Diphenylmethane diisocyanate
(Diphenylmethane
Diisocyanate, MDI)
101-68-8 C15H10N2O2 250.24
4 diphenylmethane diisocyanate impregnated filter paper collection - high performance liquid chromatography
4.1 Principle
Diphenylmethane diisocyanate (MDI) in air reacts with 1-(2-pyridyl)piperazine (1-2PP) on impregnated filter paper to form MDI-
The urea derivative is adsorbed on the filter paper, and after elution and filtration, it is determined by high performance liquid chromatography to determine the retention time, peak height or peak area.
Quantitative.
4.2 Instrument
4.2.1 Glass fiber filter paper with a pore size of 0.8 μm and a diameter of 37 mm or 40 mm.
4.2.2 Impregnated filter paper. In the fume hood, spread the glass fiber filter paper on a clean flat carrier and add 0.50 mL to the center of the filter paper.
1-2PP solution A, the solution should be saturated with the entire filter paper. After being placed for 30 minutes, it should be stored in a sealed dark container and stored in an environment of 2 ° C to 8 ° C.
One month.
4.2.3 Sampling clamp, filter material diameter is 37 mm or 40 mm.
4.2.4 Air sampler, flow rate 0.1 L/min ~ 5.0 L/min.
4.2.5 Plug-in test tube, 5 mL or 10 mL.
4.2.6 Microinjector, 10 μL or 100 μL.
4.2.7 Organic phase needle filter with a pore size of 0.45 μm.
4.2.8 Analytical balance with an accuracy of 0.00001 g and 0.001 g.
4.2.9 High performance liquid chromatograph equipped with UV detector or diode array detector, instrument operation reference conditions.
a) Column. C18 column, 250 mm × 4.6 mm × 5 μm, or other LC column with similar separation performance;
b) mobile phase. acetonitrile-ammonium acetate solution;
c) Measurement wavelength. 254 nm;
d) Flow rate. 1.0 mL/min;
e) Column temperature. 30 °C;
f) Injection volume. 20 μL.
4.3 Reagent materials
4.3.1 Unless otherwise specified, the reagents used were of analytical grade. The water is the first grade water specified in GB/T 6682.
4.3.2 Acetonitrile. chromatographically pure.
4.3.3 Dichloromethane.
4.3.4 Dimethyl sulfoxide.
4.3.5 Ammonium acetate.
4.3.6 1-(2-Pyridyl)piperazine (1-2PP). purity ≥ 98%.
4.3.7 Eluent. Measure 10 mL of dimethyl sulfoxide and pour into 90 mL of acetonitrile and mix.
4.3.8 Ammonium acetate solution (0.02 mol/L). Weigh 1.540 g of ammonium acetate, dissolve in water, and dilute to 1000 mL, and mix.
4.3.9 Acetonitrile-ammonium acetate solution. Measure 500 mL of acetonitrile into 500 mL of 0.02 mol/L ammonium acetate solution and mix.
4.3.10 1-2PP solution A (2.0 mg/mL). Weigh 0.200 g of 1-2PP and dissolve it in 100 mL of dichloromethane.
4.3.11 1-2PP solution B (10.0 mg/mL). Weigh 0.100 g of 1-2PP and dissolve it in 10 mL of acetonitrile.
4.3.12 Diphenylmethane diisocyanate (MDI). purity ≥ 98%.
4.3.13 Standard solution. accurately weigh the appropriate amount of MDI into a brown volumetric flask, dissolve it with acetonitrile and formulate MDI at a concentration of about 2.0 mg/mL.
The standard stock solution can be stored for one week in the dark at 2 °C ~ 8 °C. Dilute to a standard solution of 100 μg/mL with acetonitrile before use. Or use
Prepared by a nationally recognized standard solution.
4.4 Sample collection, transportation and storage
4.4.1 On-site sampling shall be performed in accordance with GBZ 159.
4.4.2 Short-time sampling. At the sampling point, use the sampling clamp with the impregnated filter paper to collect the sample at a fixed point sampling rate of 1 L/min for 15 min.
Air sample.
4.4.3 Long-time sampling. At the sampling point, use the sampling clamp with the impregnated filter paper, and use the fixed point or individual sampling method, 1 L/min flow rate.
Set ≤ 1 h air sample.
4.4.4 After sampling, open the sampling clamp, take out the filter paper, fold the dust face inward and fold it twice, and put it into the stopper with 4 mL of eluent.
In a test tube, transport and store after sealing. The sample can be stored for 14 days in the dark at 2 ° C ~ 8 ° C.
4.4.5 Sample blank. At the sampling point, open the sampling clamp with the impregnated filter paper, immediately remove the filter paper, and pre-load the 4 mL eluent.
In a stoppered test tube, then transported, stored and measured with the sample. Not less than 2 sample blanks per batch.
4.5 Analysis steps
4.5.1 Sample processing. The sample in the plugged test tube is vortexed and eluted for 10 min at room temperature, filtered through a needle filter, and the filtrate is tested.
set.
4.5.2 Preparation and determination of the standard series. Take at least 6 volumetric flasks, add 0.10 mL each of 1-2PP solution B, add with a micro syringe
Into 0 μL ~ 100 μL standard solution, shake for 30 s, then dilute to 5 mL with eluent, and prepare 0.00 μg/mL ~ 2.00 μg/mL MDI
Standard series. According to the operating conditions of the instrument, the high-performance liquid chromatograph is adjusted to the optimal measurement state, and each concentration of the standard series is determined separately.
Peak height or peak area. Draw a standard curve or calculate a regression equation for the corresponding MDI concentration (μg/mL) from the measured peak height or peak area.
Its correlation coefficient should be ≥0.999.
4.5.3 Sample determination. The sample and sample blank filtrates are determined using the operating conditions of the assay standard series. The measured peak height or peak area value is determined by
The standard curve or regression equation gives the concentration of MDI in the sample filtrate (μg/mL). If the concentration of the analyte in the filtrate exceeds the measurement range, wash it.
Determined after deliquoring and diluted, multiplied by the dilution factor.
4.6 Calculation
4.6.1 Convert the sample volume to the standard sample volume according to the method and requirements of GBZ 159.
4.6.2 Calculate the concentration of MDI in air according to formula (1).
DV
04 (1)
In the formula.
C── the concentration of MDI in the air in milligrams per cubic meter (mg/m3);
C0──measured the concentration of MDI in the sample filtrate (minus the sample blank) in micrograms per milliliter (g/mL);
4—The volume of the eluent in milliliters (mL);
V0——standard sampling volume in liters (L);
D ─ elution efficiency, %.
4.6.3 The time-weighted average contact concentration (CTWA) of MDI in air is calculated in accordance with GBZ 159.
4.7 Description
4.7.1 The detection limit of MDI in this method is 0.0032 μg/mL, the lower limit of quantification is 0.011 μg/mL, and the quantitative measurement range is 0.011 μg/mL~
2.00 μg/mL; the minimum detectable concentration is 0.0009 mg/m3, and the lowest quantitative concentration is 0.0029 mg/m3, based on the sample of 15 L air.
The relative standard deviation is 3.10% to 8.03%.
4.7.2 This method has a high collection efficiency (>90%) for vapor state and particle size < 2 μm aerosol state MDI. In this case, it can be sampled for a long time.
1 h ~ 4 h; for particle size > 2 μm aerosol MDI in some cases, the collection efficiency is lower, such as particle size > 10 μm MDI aerosol and dip
The stained filter paper is trapped after impact, and the MDI wrapped in it may not fully react with 1-2PP, due to shedding or air when sampling for a long time.
The other substances in the reaction are lost, and the sampling time for long-term sampling in this case should be ≤1 h. If you ca......
|