Some standard content:
ICS87.060.10
National Standard of the People's Republic of China
GB/T9335—2001
Nitrobenzene
Nitrobehzene
Published on July 13, 2001
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
Implemented on February 1, 2002
GB/T9335—2001
This standard is equivalent to the Japanese Industrial Standard JIS K4108 1995 "Nitrobenzene", which is a revision of the mandatory national standard GB9335—1988 "Nitrobenzene". The main differences between this standard and JIS K4108—1995 are: the stationary liquid of the chromatography method of this standard is methyl silicone oil (I), while the stationary liquid of JIS K4108 is methyl siloxane. This standard has two grades: superior and first-class. JIS K4108 has no classification. The main differences between this standard and GB9335-1988 are: - The particle size of the carrier used in the chromatographic column of this standard is 177μm~250μm. The particle size of the chromatographic carrier of GB9335-1988 standard is 149μm~177μm.
The quantitative method of this standard uses the peak area normalization method, and the quantitative method of GB9335-1988 uses the peak height normalization method. This standard replaces GB9335-1988 from the date of publication. This standard is proposed by the State Bureau of Petroleum and Chemical Industry. This standard is under the jurisdiction of the National Dye Standardization Technical Committee. The drafting units of this standard are: Sinopec Nanjing Chemical Plant, Shenyang Chemical Research Institute. The main drafters of this standard are Liang Zhishun and Shen Rijiong. This standard was first issued as the mandatory national standard GB9335-1988 in 1988. This standard is interpreted by the National Dye Standardization Technical Committee. 1
1 Scope
National Standard of the People's Republic of China
Nitrobenzene
Nitrobenzene
GB/T9335—2001
Replaces GB9335—1988
This standard specifies the requirements, sampling, analysis procedures, inspection rules, marking, labeling, packaging, transportation and storage of nitrobenzene. This product is mainly used in the production of dyes, pesticides, rubber accelerators, medicines, spices and explosives. Structural formula:
Molecular formula: CHsNO2
Relative molecular mass: 123.11 (according to the 1997 international relative atomic mass) 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest version of the following standards. GB190—1990 Dangerous Goods Packaging Marking
GB/T1250—1989 Method for expressing and determining limit values GB/T2385—1992 General method for determination of crystallization point of dye intermediates GB/T6678—1986 General rules for sampling of chemical products GB/T9722—1988
General rules for gas chromatography of chemical reagents
GB/T13753—1992
3 Requirements
General method for determination of moisture content in dye intermediates
Karl Fischer method and modified Karl Fischer method Nitrobenzene shall comply with the requirements of Table 1.
Table 1 Quality requirements for nitrobenzene
Crystallization point of dry product, ℃
Purity, %
Low boiling matter, %
Total amount of nitrotoluene, %
High boiling matter, %
Water, %
Superior quality
Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on July 13, 2001
Light yellow liquid
Implemented on February 1, 2002
4 Sampling
GB/T9335—2001
Sampling is carried out in batches. The number of sampling units shall comply with the provisions of 6.6 in GB/T6678—1986. When sampling, a dry glass tube with a diameter of 15mm and a length of 1m is used to take samples including the upper, middle and lower parts. The total amount of the sampled sample shall not be less than 500g. After mixing the sample carefully and homogenizing, divide it into two clean and dry ground-mouth bottles and seal them. Paste labels on the bottles and indicate: product name, batch number, manufacturer name, sampling date. One bottle is for inspection and the other is kept for reference. 5 Analysis steps
Unless otherwise specified, the reagents used in this standard are analytically pure reagents. The test results are determined according to the rounded value comparison method specified in GB/T1250-1989.
5.1 Appearance
Evaluate by visual observation.
5.2 Determination of crystallization point of dry product
The determination of crystallization point of dry product is carried out according to the method specified in GB/T2385. Take 30mL of nitrobenzene sample in a 125mL wide-mouth bottle with a lid, dry it for 30min with 10g of 3A molecular sieve activated at 550℃ for 2h, and take the supernatant to determine the crystallization point. 5.3 Chromatographic determination of nitrobenzene purity and organic impurities 5.3.1 Method summary
After the nitrobenzene sample enters the chromatographic system, under appropriate chromatographic operating conditions, the components are separated, detected by hydrogen flame ionization detector, and quantified by peak area normalization method.
5.3.2 Instruments
a) Gas chromatograph: sensitivity and stability meet the requirements of GB/T9722. b) Chromatographic column: stainless steel column or glass column with an inner diameter of 3mm and a length of 2m. c) Detector: hydrogen flame ionization detector. d) Recorder: chromatographic data processor.
e) Injector: 1μL micro syringe.
5.3.3 Filler
a) Stationary liquid: methyl silicone oil (I) 1
b) Carrier: white 101 silanized carrier, particle size 149μm~177μm (100 mesh~80 mesh). c) Coating degree: stationary liquid/carrier = 25/100. 5.3.4 Coating of stationary liquid
Weigh 2.0g methyl silicone oil (I) into a 250mL beaker, add 25mL ether to dissolve it, slowly pour 8.0g dry carrier into the beaker to completely soak it, soak it for 30 minutes, heat it under an infrared lamp to evaporate the solvent, and make the coating uniform. After the solvent evaporates, dry it in an oven at 100℃ for about 30 minutes.
5.3.5 Filling method
Connect one end of the chromatographic column connected to the detector to the vacuum pump, and slowly load the freshly dried stationary phase into the other end to make the chromatographic column evenly and tightly filled (the column loading volume is about 5g), and plug the two ends of the filled chromatographic column with glass wool for aging. 5.3.6 Aging of the chromatographic column
Put the filled chromatographic column into the chromatographic column box and age it for about 8 hours at a nitrogen flow rate of about 10mL/min and a column box temperature of 200℃. During the aging process, the chromatographic column should be disconnected from the detector.
Instructions for use:
The Japanese Industrial Standard stationary liquid uses methylsiloxane. 2
5.3.7 Chromatographic operating conditionsbzxZ.net
Column box temperature: 165℃;
Detection temperature: 260℃;
Vaporization temperature: 260℃;
Carrier gas (nitrogen) flow rate: 25mL/min; Combustion gas (hydrogen) flow rate: 30mL/min; Auxiliary gas (air) flow rate: 400mL/min; Injection volume: 0.4μL;
Quantitative method: Peak area normalization method;
Paper speed: 300mm/h;
GB/T9335—2001
Resolution: 1.0 or more (based on nitrobenzene peak and o-nitrotoluene peak). Select appropriate chromatographic operating conditions according to the requirements of this standard. 5.3.8 Determination of relative correction factor
5.3.8.1 Preparation of calibration mixed solution
a) Reagents
Nitrobenzene: no impurities detected under the standard test conditions; o-nitrotoluene,
p-nitrotoluene:
m-dinitrobenzene.
b) Preparation of single calibration solution
Weigh various reagents (accurate to 0.0002g) according to the requirements of Table 2 into a clean and dry 25mL volumetric flask, dissolve with nitrobenzene and dilute to the scale. The shelf life of the single calibration solution is three months. Table 2 Preparation of single calibration solution
Name of single calibration solution
Name of reagent
Reagent mass/g
Volume after dilution/mL
c Preparation of calibration mixed solution
o-Nitrotoluene
p-Nitrotoluene
m-Dinitrobenzene
According to the requirements of Table 3, use a pipette to pipette the single calibration solution into a clean and dry 10mL volumetric flask of known mass, dilute to the mark with nitrobenzene, mix well, and weigh the mass of the solution (accurate to 0.001g). The service life of the calibration mixed solution is one month. Table 3 Preparation of calibration mixed solution
Name of single calibration solution
Volume after dilution
Amount of single calibration solution added
5.3.8.2 Determination of relative correction factor
GB/T9335—2001
Start the chromatograph. After the operating conditions are stable, take 0.4μL of calibration mixed solution for injection. After the peak is eluted, calculate the relative correction factor according to the peak area and corresponding mass of each component of the calibration mixed solution. The nitrobenzene peak is used as the reference peak. The relative correction factor is calculated as follows:
Where: f!——Relative correction factor of component i mi
Mass of component i, mg;
Ai——Peak area of component i, mm2;
-Mass of nitrobenzene, mg,
A. Peak area of nitrobenzene, mm2.
Note: The relative correction factor can be calculated by the chromatographic data processor. 5.3.9 Inspection steps
(1)
Start the instrument. After the operating conditions are stable, draw 0.4uL of nitrobenzene sample for injection. After the peak is eluted, the mass fraction (%) of each component is calculated as follows:
Where: X—mass fraction of component i, %r
—peak area attenuation multiple of component i;
f——relative correction factor of component i,
A—peak area of component i, mm\;
(rfiA)
—water mass fraction measured by 4.4, %. X(100
Among them, the components before the nitrobenzene peak are collectively referred to as low-boiling substances, and the relative correction factor is calculated in terms of benzene; the components after the nitrotoluene peak until the relative retention time of 4 with the nitrobenzene peak are collectively referred to as high-boiling substances, and the relative correction factor is calculated in terms of m-dinitrobenzene. The difference between the two parallel determination results of nitrobenzene should not be greater than 0.2%. The arithmetic mean of the two parallel determination results is taken as the determination result. 5.3.10 Chromatographic legend
Under the chromatographic operating conditions specified in this standard, the chromatographic peaks and relative retention times t of the main components of nitrobenzene are shown in Table 4. Table 4 Chromatographic peaks and relative retention times of main components Peak number||tt| |The legend of the chromatogram is shown in Figure 1:
5.4 Determination of moisture
Nitrotoluene
The moisture content shall be determined according to the method specified in GB/T13753. In arbitration, the Karl Fischer method shall be used.
6 Inspection rules
6.1 Inspection classification
All items specified in Table 1 are factory inspection items. 6.2 Factory inspection
O-nitrotoluene
P-nitrotoluene
Meta-dinitrobenzene
Nitrobenzene shall be inspected by the quality inspection department of the manufacturer. The manufacturer shall ensure that each batch of nitrobenzene shipped meets the requirements of this standard .
6.3 Re-test
GB/T9335—2001
If any of the test results do not meet the requirements of this standard, samples should be taken from twice the amount of packaging containers for re-testing. Even if only one of the test results does not meet the requirements of this standard, the entire batch of products cannot be accepted. 1
7 Marking, labeling, packaging, transportation and storage 7.1 Marking, labeling
Nitrobenzene chromatogram
Each packaging container of nitrobenzene should have a firm and clear mark indicating: product name, grade, registered trademark, net content, manufacturer name, address, standard The batch number, production date, and product quality inspection certificate shall be marked with warning signs in accordance with the provisions of GB190. The batch number, production date, and product quality inspection certificate can also be printed on the label. 7.2 Packaging
Nitrobenzene is packaged in clean and dry steel drums or shipped in tank trucks. When packaged in steel drums, the net content of each drum is 100kg or 200kg. Other packaging can be negotiated with the user.
7.3 Transportation
Nitrobenzene should be protected from sunlight and rain during transportation, and should be handled with care. 7.4 Storage
Nitrobenzene should be stored in a cool and dry place, away from fire sources. 5
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