Some standard content:
ICS 71.100.01
National Standard of the People's Republic of China
GB/T4840.1—1999
p-Nitroaniline
Issued on 1999-06-08
Implemented on 1999-12-01
State Administration of Quality and Technical Supervision
GB/T 4840.1—1999
This standard is equivalent to Japanese Industrial Standard JIS K4105:1995 "Nitroanilines" and uses gas chromatography to revise the original standard GB/T4840—1984 "p-Nitroaniline". The revised standard is equivalent to the Japanese Industrial Standard JIS K4105: 1995 in terms of technical content; in terms of writing format, it is written in accordance with GB/T 1.1-1993 "Guidelines for Standardization Work Unit 1: Rules for Drafting and Presentation of Standards Part 1 Basic Regulations for Standard Writing" and GB/T 1.3-1997 "Guidelines for Standardization Work Unit 1: Rules for Drafting and Presentation of Standards Part 3 Regulations for Writing Product Standards". The inspection items and technical indicators are determined according to the needs of domestic and foreign users and the actual situation of domestic production.
The main difference between this standard and the Japanese Industrial Standard JIS K4105: 1995 "Nitroanilines" is that the carrier used in the Japanese Industrial Standard is Chromosorb W-HP with a diameter of 177~250μm, while the carrier used in this standard is Chromosorb G-AWDMCS with a coating degree of 4/100.
The main difference between this standard and the original standard GB/T4840-1984 "p-Nitroaniline" is that the three levels in the technical indicators of the original standard are changed to two specifications of dry product and damp product, and the sampling inspection item of hydrochloric acid insoluble matter in the original standard is cancelled. The inspection items are determined to be appearance, initial melting point of dry product, purity (total amino value is measured for damp product), p-nitrochlorobenzene content, low boiling point content, o- and m-nitroaniline content, high boiling point content, and moisture content (damp product is not measured).
This standard will replace GB/T48401984 from the date of entry into force. This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is technically managed by the National Dye Standardization Technical Committee. This standard was jointly drafted by Shenyang Chemical Research Institute and Zhenjiang Fine Chemical Co., Ltd. The main drafters of this standard are: Li Chunmei, Ren Kui, and Wang Maofan. This standard was first published in 1984.
1 Scope
National Standard of the People's Republic of China
p-Nitroaniline
GB/T4840.1—1999
Replaces GB/T4840—1984
This standard specifies the requirements, sampling, test methods, inspection rules, as well as marking, labeling, packaging, transportation and storage of p-nitroaniline. This standard applies to p-nitroaniline obtained by high-pressure ammonolysis, separation and filtration of p-nitrochlorobenzene. This product is mainly used in dye, pigment and pharmaceutical industries.
Structural formula:
Molecular formula: CH6N202
Relative molecular mass: 138.13 (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 was published, the versions shown were all valid. All standards will be revised. All parties using this standard should explore the possibility of using the latest version of the following standards. GB190—1990 Dangerous Goods Packaging Marking
GB191—1990 Pictorial Marking of Packaging Storage and Transportation
GB/T601—1988 Preparation of Standard Solutions for Titration Analysis (Volume Analysis) of Chemical Reagents GB/T603—1988
3 Preparation of Preparations and Products Used in Chemical Reagent Test Methods GB/T1250—1989
Method for Representing and Determining Limit Values General Method for Determination of Melting Point Range of Dye Intermediates GB/T2 384—1992
GB/T6682—1992
GB/T9722—1988
GB/T13753—1992
3 Requirements
Specifications and test methods for water used in analytical laboratories (negISo3696:1987) General rules for gas chromatography of chemical reagents
General method for determination of water content in dye intermediates Karl Fischer method and modified Karl Fischer method The quality of p-nitroaniline shall conform to the requirements of Table 1. Approved by the State Administration of Quality and Technical Supervision on June 8, 1999, and implemented on December 1, 1999
Initial melting point of dry product, ℃
Total amino value, %
Purity of p-nitroaniline, %
Content of p-nitrochlorobenzene, %
Low boiling matter content, %
Total amount of m- and o-nitroaniline, %
High boiling matter content, %
Moisture content, %
4 Sampling
GB/T4840.1—1999
Table 1 Quality requirements for p-nitroaniline
Yellow to yellow-brown crystals
From each batch of products (a batch of uniform products), sample 30% of the number of packaging barrels. In case of small batches, not less than 3 barrels. When sampling, use a probe to take samples from the upper, middle and lower parts. The total amount of samples shall not be less than 200g. After grinding and mixing the samples, divide them into two clean and dry wide-mouth bottles with ground stoppers. Paste labels on the bottles, indicating: manufacturer name, product name, grade, batch number and sampling date. One bottle is for inspection, and the other bottle is sealed with paraffin and kept for future reference. 5 Test method
Unless otherwise specified, the reagents used in this standard refer to analytical pure reagents; water should meet the third-grade water specifications in GB/T6682. The test results are determined according to the rounded value comparison method in GB/T1250. 5.1 Appearance
The appearance is determined visually.
5.2 Determination of total amino value
5.2.1 Reagents and materials
Hydrochloric acid;
Sodium nitrite: c(NaNO2)=0.5mol/L standard titration solution, prepared and calibrated according to GB/T601 and GB/T603, but starch potassium iodide test paper is used for endpoint judgment;
Starch potassium iodide test paper.
5.2.2 Determination steps
Weigh about 2g (accurate to 0.0002g) of the damp product sample and place it in a 400mL clean and dry beaker, add 30mL hydrochloric acid and 100mL distilled water, heat to dissolve, dilute to 300mL with distilled water, and cool to 010℃. Then insert the tip of the burette into the solution, add 0.5mol/L sodium nitrite standard titration solution (accounting for about 95% of the total required amount) at one time while stirring continuously, then lift the tip of the burette away from the liquid surface, and add 0.5mol/L sodium nitrite standard titration solution drop by drop until the starch potassium iodide test paper turns slightly blue. After 5 minutes, if it still turns slightly blue using the same method, it is the end point. Record the volume V1 of the sodium nitrite standard titration solution consumed, and do a blank test under the same conditions.
5.2.3 Expression and calculation of results
The mass percentage of the total amino value is represented by X1 and calculated according to formula (1): X1 = 0.1381×C(V/-V)×100
·（1）)
GB/T4840.1—1999
Wherein: C——concentration of sodium nitrite standard titration solution, mol/L; Vi——volume of sodium nitrite standard titration solution consumed by the titrated sample, mL; V. —volume of sodium nitrite standard titration solution consumed by the blank test, mL; m——mass of p-nitroaniline sample, g; 0.1381——mass of p-nitroaniline in grams equivalent to 1.00mL sodium nitrite standard titration solution [c(NaNO2)]=1.000mol/L.
The difference between the two determination results is not greater than 0.3%, and the arithmetic mean is taken as the determination result. 5.3 Determination of initial melting point of dry product
Perform according to GB/T2384. The drying temperature is 100-105℃, and the difference between the two parallel determination results is not greater than 0.2℃, and the arithmetic mean is taken as the determination result.
5.4 Determination of the purity of p-nitroaniline and its organic impurity content 5.4.1 Method summary
Use gas chromatography to separate p-nitroaniline and organic impurity components on a packed gas chromatographic column, detect with a hydrogen flame ionization detector (FID), and quantify by peak area normalization method. 5.4.2 Instruments and Devices
Gas chromatograph: The sensitivity and stability of the instrument shall comply with the provisions of GB/T9722. Detector: Hydrogen flame ionization detector FID; Data processor: Recorder with full scale of 10mV and response time of 1s or a data processor with this function; Chromatographic column: Inner diameter 3.2~3.5mm, 2m long glass column or stainless steel column; micro syringe: 10μL.
5.4.3 Preparation of chromatographic column
5.4.3.1 Filler
Carrier: Chromosorb G-AWDMCS177~250μm (80~60 mesh) Stationary liquid: phenylsiloxane OV-17 (maximum operating temperature 300℃); solvent: chloroform;
Coating degree: stationary liquid/carrier = 4/100
5.4.3.2 Stationary liquid coating
Weigh 0.8g 0V-17 in a 100mL beaker, then add chloroform equivalent to the volume of 20g carrier, wait until it is completely dissolved, and slowly pour in 20g carrier to make it completely soaked (about 10min). Place the beaker in a fume hood and allow the solvent to evaporate slowly under an infrared lamp until it is dry (the beaker should be tapped frequently to ensure that it is evenly coated). Then move to a 90-100℃ oven and dry for about 30 minutes, then take it out for later use. 5.4.3.3 Filling of stationary phase
Plug glass wool into one end of the chromatographic column connected to the detector, wrap it with gauze, connect it to a vacuum pump, and connect a funnel to the other end. Slowly pour the dried stationary phase into the column under vacuum, tap the column to make the filling even and tight. After filling, continue tapping for 5 to 10 minutes, plug the filled column with glass wool, and prepare for aging.
5.4.3.4 Aging of chromatographic column
Put the filled column into the column box of the chromatograph, do not connect the detector after the column, pass nitrogen at a flow rate of 5 to 10 mL/min, and age at 270℃ for 8 to 10 hours.
5.4.4 Chromatographic conditions (optimal operating conditions can be selected according to different instruments) Column temperature: 220℃;
Vaporization temperature: 250℃;
Detection temperature: 250℃;
Carrier gas flow rate (N): 50mL/min;
Combustion gas flow rate (H2): 50mL/min; 3
Auxiliary gas flow rate (O2): 500mL/min; Paper speed: 3mm/min;
Injection volume: 2~3μL;
Quantitative method: Peak area normalization method;
Resolution: ≥ 1.0
GB/T4840.1—1999
5.4.5 Preparation of standard stock solution and determination of correction factor 5.4.5.1 Reagents
Ethyl acetate;
p-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); o-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); m-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); p-Nitrochlorobenzene: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions). 5.4.5.2 Preparation of standard stock solution
According to the requirements of Table 2, weigh various reagents (accurate to 0.0002g) accurately into a clean and dry volumetric flask, dissolve with ethyl acetate, and dilute to the scale. The shelf life of the standard stock solution is three months. Table 2 Preparation of standard stock solution
Reagent name
Weighing amount, 8
Volume after dilution, mL
p-Nitrochlorobenzene
5.4.5.3 Preparation of standard mixed solution
Nitroaniline
m-Nitroaniline
p-Nitroaniline
In five numbered 10mL brown volumetric flasks, prepare according to Table 3 to obtain mixed solutions No. 1, 2, 3, 4, and 5. The shelf life of the standard mixed solution is one month.
Single calibration solution
Solution A (p-nitrochlorobenzene), mL
Solution B (o-nitroaniline), mL
Solution C (m-nitroaniline), mL
Solution D (p-nitroaniline), mL
Total volume after dilution with ethyl acetate, mL
5.4.5.4 Determination and calculation of correction factor
Table 3 Preparation of standard mixed solution
Under the selected chromatographic conditions, add 2μL of the standard mixed solution respectively. After the peaks of each component have been eluted, calculate the correction factor of each component according to formula (2). The peak before p-nitrochlorobenzene is a low-boiling substance, and the correction factor is calculated according to p-nitrochlorobenzene; the peak after p-nitroaniline is a high-boiling substance, and the correction factor is calculated according to p-nitroaniline. The correction factor of each component is calculated according to formula (2): f
W| ...
GB/T4840.1—1999
1-Solvent, 2-Low boiling substances, 3-Nitrochlorobenzene, 4-Nitroaniline, 5-Nitroaniline, 6-Figure 1 Gas chromatogram of p-nitroaniline
5.4.6 Analysis steps
-P-nitroaniline; 7-High boiling substances
Weigh 0.5g (accurate to 0.01g) of p-nitroaniline (accurate to 0.01g) in a 10mL brown volumetric flask and dilute to the mark with ethyl acetate. Inject the sample under the selected conditions, and after the peaks of each component have been completely eluted, calculate the percentage of each component according to the peak area and relative correction factor of each component according to formula (3) and (4). See Figure 1 for the chromatogram. 5.4.7 Expression and calculation of results
The mass percentage of p-nitroaniline in dry product is calculated according to formula (3): fA.
W——the percentage of p-nitroaniline in dry product; correction factor of a component;
the peak area of a component, mm2;
W——the moisture content of p-nitroaniline in dry product. X(100-W)
The percentage of organic impurities in p-nitroaniline in dry product and damp product is calculated according to formula (4): x,=
W——the percentage of a component; f.—the correction factor of component i;
A——the peak area of component i, mm2.
·（3）
...........(4)
The difference between the two parallel determination results of purity shall not exceed 0.2%, and the difference between the two parallel determination results of each organic impurity content shall not exceed 0.05%. The arithmetic mean value shall be taken as the determination result. 5.5 Determination of moisture content
The moisture content of dry p-nitroaniline shall be carried out in accordance with the provisions of GB/T13753. Using chloroform + methanol = (3+1) as solvent, the difference between the two parallel 5
GB/T4840.1-1999
determination results shall not exceed 0.02%. The arithmetic mean value shall be taken as the determination result. Sample weight 0.5~1g. 6 Inspection rules
6.1 Inspection classification
All items specified in Table 1 are factory inspection items. 6.2 Inspection by the manufacturer
Para-nitroaniline shall be inspected by the quality inspection department of the manufacturer in accordance with the requirements of this standard. The manufacturer shall ensure that all products shipped out of the factory meet the requirements of this standard. Each batch of products shipped out of the factory shall be accompanied by a quality certificate in a certain format. 6.3 User acceptance
The user unit has the right to inspect the received para-nitroaniline products in accordance with the provisions of this standard to check whether they meet the requirements of this standard.
6.4 Re-inspection
If one of the indicators in the inspection results does not meet the requirements of this standard, samples shall be taken from twice the amount of packaging for re-inspection. If only one index does not meet the requirements of this standard in the re-inspection results, the entire batch of products cannot be accepted. 7 Marking, labeling, packaging, transportation and storage 7.1 Marking
The p-nitroaniline packaging barrel should have clear markings, indicating the manufacturer's name, address, product name, trademark, batch number, grade, gross weight, net weight and production date, and the word "toxic" and diagram according to the requirements of GB190 and GB191. 7.2 Labeling
Each batch of packaged products should be accompanied by a label of a certain format, which includes: manufacturer's name, address, product name, batch number, grade, net weight, production date, proof that the product quality meets the requirements of this standard and the number of this standard. 7.3 Packaging
Para-nitroaniline is packaged in woven bags or iron drums lined with plastic bags (plastic bags must be tied), with a net weight of 25kg per bag (barrel). If the user requires other packaging, it can be negotiated and determined.
7.4 Transportation
Prevent exposure to sunlight, collision and rain during transportation. 7.5 Storage
The product should be stored in a cool, dry and ventilated warehouse.1 Filler
Carrier: Chromosorb G-AWDMCS177~250μm (80~60 mesh) Fixative: Phenylsiloxane OV-17 (maximum operating temperature 300℃); Solvent: Chloroform;
Coating degree: Fixative/carrier = 4/100
5.4.3.2 Coating of fixative
Weigh 0.8g 0V-17 in a 100mL beaker, then add chloroform equivalent to the volume of 20g carrier, and after it is completely dissolved, slowly pour in 20g carrier to make it completely soaked (about 10min). Place the beaker in a fume hood and under an infrared lamp, let the solvent evaporate slowly until dry (the beaker should be tapped frequently to ensure uniform coating). Then move to a 90100℃ oven to dry for about 30min, and take it out for use. 5.4.3.3 Filling of stationary phase
Plug glass wool into one end of the chromatographic column connected to the detector, wrap it with gauze, connect it to a vacuum pump, and connect a funnel to the other end. Slowly pour in the dried stationary phase under vacuum, tap the chromatographic column gently to make the filling even and tight. After filling, continue tapping for 5 to 10 minutes, plug the filled chromatographic column with glass wool, and prepare for aging.
5.4.3.4 Aging of chromatographic column
Install the filled chromatographic column into the column box of the chromatograph, do not connect the detector after the column, pass nitrogen at a flow rate of 5 to 10 mL/min, and age at 270°C for 8 to 10 hours.
5.4.4 Chromatographic conditions (optimal operating conditions can be selected according to different instruments) Column temperature: 220℃;
Vaporization temperature: 250℃;
Detection temperature: 250℃;
Carrier gas flow rate (N): 50mL/min;
Combustion gas flow rate (H2): 50mL/min; 3
Auxiliary gas flow rate (O2): 500mL/min; Paper speed: 3mm/min;
Injection volume: 2~3μL;
Quantitative method: Peak area normalization method;
Resolution: ≥ 1.0
GB/T4840.1—1999
5.4.5 Preparation of standard stock solution and determination of correction factor 5.4.5.1 Reagents
Ethyl acetate;
p-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); o-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); m-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); p-Nitrochlorobenzene: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions). 5.4.5.2 Preparation of standard stock solution
According to the requirements of Table 2, weigh various reagents (accurate to 0.0002g) accurately into a clean and dry volumetric flask, dissolve with ethyl acetate, and dilute to the scale. The shelf life of the standard stock solution is three months. Table 2 Preparation of standard stock solution
Reagent name
Weighing amount, 8
Volume after dilution, mL
p-Nitrochlorobenzene
5.4.5.3 Preparation of standard mixed solution
Nitroaniline
m-Nitroaniline
p-Nitroaniline
In five numbered 10mL brown volumetric flasks, prepare according to Table 3 to obtain mixed solutions No. 1, 2, 3, 4, and 5. The shelf life of the standard mixed solution is one month.
Single calibration solution
Solution A (p-nitrochlorobenzene), mL
Solution B (o-nitroaniline), mL
Solution C (m-nitroaniline), mL
Solution D (p-nitroaniline), mL
Total volume after dilution with ethyl acetate, mL
5.4.5.4 Determination and calculation of correction factor
Table 3 Preparation of standard mixed solution
Under the selected chromatographic conditions, add 2μL of the standard mixed solution respectively. After the peaks of each component have been eluted, calculate the correction factor of each component according to formula (2). The peak before p-nitrochlorobenzene is a low-boiling substance, and the correction factor is calculated according to p-nitrochlorobenzene; the peak after p-nitroaniline is a high-boiling substance, and the correction factor is calculated according to p-nitroaniline. The correction factor of each component is calculated according to formula (2): f
W| ...
GB/T4840.1—1999
1-Solvent, 2-Low boiling substances, 3-Nitrochlorobenzene, 4-Nitroaniline, 5-Nitroaniline, 6-Figure 1 Gas chromatogram of p-nitroaniline
5.4.6 Analysis steps
-P-nitroaniline; 7-High boiling substances
Weigh 0.5g (accurate to 0.01g) of p-nitroaniline (accurate to 0.01g) in a 10mL brown volumetric flask and dilute to the mark with ethyl acetate. Inject the sample under the selected conditions, and after the peaks of each component have been completely eluted, calculate the percentage of each component according to the peak area and relative correction factor of each component according to formula (3) and (4). See Figure 1 for the chromatogram. 5.4.7 Expression and calculation of results
The mass percentage of p-nitroaniline in dry product is calculated according to formula (3): fA.
W——the percentage of p-nitroaniline in dry product; correction factor of a component;
the peak area of a component, mm2;
W——the moisture content of p-nitroaniline in dry product. X(100-W)
The percentage of organic impurities in p-nitroaniline in dry product and damp product is calculated according to formula (4): x,=
W——the percentage of a component; f.—the correction factor of component i;
A——the peak area of component i, mm2.
·（3）
...........(4)
The difference between the two parallel determination results of purity shall not exceed 0.2%, and the difference between the two parallel determination results of each organic impurity content shall not exceed 0.05%. The arithmetic mean value shall be taken as the determination result. 5.5 Determination of moisture content
The moisture content of dry p-nitroaniline shall be carried out in accordance with the provisions of GB/T13753. Using chloroform + methanol = (3+1) as solvent, the difference between the two parallel 5
GB/T4840.1-1999
determination results shall not exceed 0.02%. The arithmetic mean value shall be taken as the determination result. Sample weight 0.5~1g. 6 Inspection rules
6.1 Inspection classification
All items specified in Table 1 are factory inspection items. 6.2 Inspection by the manufacturer
Para-nitroaniline shall be inspected by the quality inspection department of the manufacturer in accordance with the requirements of this standard. The manufacturer shall ensure that all products shipped out of the factory meet the requirements of this standard. Each batch of products shipped out of the factory shall be accompanied by a quality certificate in a certain format. 6.3 User acceptance
The user unit has the right to inspect the received para-nitroaniline products in accordance with the provisions of this standard to check whether they meet the requirements of this standard.
6.4 Re-inspection
If one of the indicators in the inspection results does not meet the requirements of this standard, samples shall be taken from twice the amount of packaging for re-inspection. If only one index does not meet the requirements of this standard in the re-inspection results, the entire batch of products cannot be accepted. 7 Marking, labeling, packaging, transportation and storage 7.1 Marking
The p-nitroaniline packaging barrel should have clear markings, indicating the manufacturer's name, address, product name, trademark, batch number, grade, gross weight, net weight and production date, and the word "toxic" and diagram according to the requirements of GB190 and GB191. 7.2 Labeling
Each batch of packaged products should be accompanied by a label of a certain format, which includes: manufacturer's name, address, product name, batch number, grade, net weight, production date, proof that the product quality meets the requirements of this standard and the number of this standard. 7.3 Packaging
Para-nitroaniline is packaged in woven bags or iron drums lined with plastic bags (plastic bags must be tied), with a net weight of 25kg per bag (barrel). If the user requires other packaging, it can be negotiated and determined.
7.4 Transportation
Prevent exposure to sunlight, collision and rain during transportation. 7.5 Storage
The product should be stored in a cool, dry and ventilated warehouse.1 Filler
Carrier: Chromosorb G-AWDMCS177~250μm (80~60 mesh) Fixative: Phenylsiloxane OV-17 (maximum operating temperature 300℃); Solvent: Chloroform;
Coating degree: Fixative/carrier = 4/100
5.4.3.2 Coating of fixative
Weigh 0.8g 0V-17 in a 100mL beaker, then add chloroform equivalent to the volume of 20g carrier, and after it is completely dissolved, slowly pour in 20g carrier to make it completely soaked (about 10min). Place the beaker in a fume hood and under an infrared lamp, let the solvent evaporate slowly until dry (the beaker should be tapped frequently to ensure uniform coating). Then move to a 90100℃ oven to dry for about 30min, and take it out for use. 5.4.3.3 Filling of stationary phase
Plug glass wool into one end of the chromatographic column connected to the detector, wrap it with gauze, connect it to a vacuum pump, and connect a funnel to the other end. Slowly pour in the dried stationary phase under vacuum, tap the chromatographic column gently to make the filling even and tight. After filling, continue tapping for 5 to 10 minutes, plug the filled chromatographic column with glass wool, and prepare for aging.
5.4.3.4 Aging of chromatographic column
Install the filled chromatographic column into the column box of the chromatograph, do not connect the detector after the column, pass nitrogen at a flow rate of 5 to 10 mL/min, and age at 270°C for 8 to 10 hours.
5.4.4 Chromatographic conditions (optimal operating conditions can be selected according to different instruments) Column temperature: 220℃;
Vaporization temperature: 250℃;
Detection temperature: 250℃;
Carrier gas flow rate (N): 50mL/min;
Combustion gas flow rate (H2): 50mL/min; 3
Auxiliary gas flow rate (O2): 500mL/min; Paper speed: 3mm/min;
Injection volume: 2~3μL;
Quantitative method: Peak area normalization method;
Resolution: ≥ 1.0
GB/T4840.1—1999
5.4.5 Preparation of standard stock solution and determination of correction factor 5.4.5.1 Reagents
Ethyl acetate;
p-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); o-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); m-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); p-Nitrochlorobenzene: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions). 5.4.5.2 Preparation of standard stock solution
According to the requirements of Table 2, weigh various reagents (accurate to 0.0002g) accurately into a clean and dry volumetric flask, dissolve with ethyl acetate, and dilute to the scale. The shelf life of the standard stock solution is three months. Table 2 Preparation of standard stock solution
Reagent name
Weighing amount, 8
Volume after dilution, mL
p-Nitrochlorobenzene
5.4.5.3 Preparation of standard mixed solution
Nitroaniline
m-Nitroaniline
p-Nitroaniline
In five numbered 10mL brown volumetric flasks, prepare according to Table 3 to obtain mixed solutions No. 1, 2, 3, 4, and 5. The shelf life of the standard mixed solution is one month.
Single calibration solution
Solution A (p-nitrochlorobenzene), mL
Solution B (o-nitroaniline), mL
Solution C (m-nitroaniline), mL
Solution D (p-nitroaniline), mL
Total volume after dilution with ethyl acetate, mL
5.4.5.4 Determination and calculation of correction factor
Table 3 Preparation of standard mixed solution
Under the selected chromatographic conditions, add 2μL of the standard mixed solution respectively. After the peaks of each component have been eluted, calculate the correction factor of each component according to formula (2). The peak before p-nitrochlorobenzene is a low-boiling substance, and the correction factor is calculated according to p-nitrochlorobenzene; the peak after p-nitroaniline is a high-boiling substance, and the correction factor is calculated according to p-nitroaniline. The correction factor of each component is calculated according to formula (2): f
W| ...
GB/T4840.1—1999
1-Solvent, 2-Low boiling substances, 3-Nitrochlorobenzene, 4-Nitroaniline, 5-Nitroaniline, 6-Figure 1 Gas chromatogram of p-nitroaniline
5.4.6 Analysis steps
-P-nitroaniline; 7-High boiling substances
Weigh 0.5g (accurate to 0.01g) of p-nitroaniline (accurate to 0.01g) in a 10mL brown volumetric flask and dilute to the mark with ethyl acetate. Inject the sample under the selected conditions, and after the peaks of each component have been completely eluted, calculate the percentage of each component according to the peak area and relative correction factor of each component according to formula (3) and (4). See Figure 1 for the chromatogram. 5.4.7 Expression and calculation of results
The mass percentage of p-nitroaniline in dry product is calculated according to formula (3): fA.
W——the percentage of p-nitroaniline in dry product; correction factor of a component;
the peak area of a component, mm2;
W——the moisture content of p-nitroaniline in dry product. X(100-W)
The percentage of organic impurities in p-nitroaniline in dry product and damp product is calculated according to formula (4): x,=
W——the percentage of a component; f.—the correction factor of component i;
A——the peak area of component i, mm2.
·（3）
...........(4)
The difference between the two parallel determination results of purity shall not exceed 0.2%, and the difference between the two parallel determination results of each organic impurity content shall not exceed 0.05%. The arithmetic mean value shall be taken as the determination result. 5.5 Determination of moisture content
The moisture content of dry p-nitroaniline shall be carried out in accordance with the provisions of GB/T13753. Using chloroform + methanol = (3+1) as solvent, the difference between the two parallel 5
GB/T4840.1-1999
determination results shall not exceed 0.02%. The arithmetic mean value shall be taken as the determination result. Sample weight 0.5~1g. 6 Inspection rules
6.1 Inspection classification
All items specified in Table 1 are factory inspection items. 6.2 Inspection by the manufacturer
Para-nitroaniline shall be inspected by the quality inspection department of the manufacturer in accordance with the requirements of this standard. The manufacturer shall ensure that all products shipped out of the factory meet the requirements of this standard. Each batch of products shipped out of the factory shall be accompanied by a quality certificate in a certain format. 6.3 User acceptance
The user unit has the right to inspect the received para-nitroaniline products in accordance with the provisions of this standard to check whether they meet the requirements of this standard.
6.4 Re-inspection
If one of the indicators in the inspection results does not meet the requirements of this standard, samples shall be taken from twice the amount of packaging for re-inspection. If only one index does not meet the requirements of this standard in the re-inspection results, the entire batch of products cannot be accepted. 7 Marking, labeling, packaging, transportation and storage 7.1 Marking
The p-nitroaniline packaging barrel should have clear markings, indicating the manufacturer's name, address, product name, trademark, batch number, grade, gross weight, net weight and production date, and the word "toxic" and diagram according to the requirements of GB190 and GB191. 7.2 Labeling
Each batch of packaged products should be accompanied by a label of a certain format, which includes: manufacturer's name, address, product name, batch number, grade, net weight, production date, proof that the product quality meets the requirements of this standard and the number of this standard. 7.3 Packaging
Para-nitroaniline is packaged in woven bags or iron drums lined with plastic bags (plastic bags must be tied), with a net weight of 25kg per bag (barrel). If the user requires other packaging, it can be negotiated and determined.
7.4 Transportation
Prevent exposure to sunlight, collision and rain during transportation. 7.5 Storage
The product should be stored in a cool, dry and ventilated warehouse.8g0V-17 in a 100mL beaker, then add chloroform equivalent to the volume of 20g carrier. After it is completely dissolved, slowly pour in 20g carrier to make it completely soaked (about 10 minutes). Place the beaker in a fume hood and slowly evaporate the solvent under an infrared lamp until it is dry (the beaker should be tapped frequently to ensure that it is evenly coated). Then move it to a 90100℃ oven and dry it for about 30 minutes, then take it out for use. 5.4.3.3 Filling of the stationary phase
Plug the end of the chromatographic column connected to the detector with glass wool, wrap it with gauze, connect it to a vacuum pump, and connect the other end to a funnel. Slowly pour in the dried stationary phase under vacuum, tap the chromatographic column gently to make the filling even and tight. After filling, continue tapping for 5 to 10 minutes, plug the filled chromatographic column with glass wool, and prepare for aging.
5.4.3.4 Aging of chromatographic column
Install the filled chromatographic column into the column box of the chromatograph, without connecting a detector behind the column, and pass nitrogen at a flow rate of 5-10mL/min, and age at 270℃ for 8-10h.
5.4.4 Chromatographic conditions (optimal operating conditions can be selected according to different instruments) Column temperature: 220℃;
Vaporization temperature: 250℃;
Detection temperature: 250℃;
Carrier gas flow rate (N): 50mL/min;
Combustion gas flow rate (H2): 50mL/min;3
Auxiliary gas flow rate (O2): 500mL/min; Paper speed: 3mm/min;
Injection volume: 2~3μL;
Quantitative method: Peak area normalization method;
Resolution: ≥ 1.0
GB/T4840.1—1999
5.4.5 Preparation of standard stock solution and determination of correction factor 5.4.5.1 Reagents
Ethyl acetate;
p-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); o-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); m-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); p-Nitrochlorobenzene: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions). 5.4.5.2 Preparation of standard stock solution
According to the requirements of Table 2, weigh various reagents (accurate to 0.0002g) accurately into a clean and dry volumetric flask, dissolve with ethyl acetate, and dilute to the scale. The shelf life of the standard stock solution is three months. Table 2 Preparation of standard stock solution
Reagent name
Weighing amount, 8
Volume after dilution, mL
p-Nitrochlorobenzene
5.4.5.3 Preparation of standard mixed solution
Nitroaniline
m-Nitroaniline
p-Nitroaniline
In five numbered 10mL brown volumetric flasks, prepare according to Table 3 to obtain mixed solutions No. 1, 2, 3, 4, and 5. The shelf life of the standard mixed solution is one month.
Single calibration solution
Solution A (p-nitrochlorobenzene), mL
Solution B (o-nitroaniline), mL
Solution C (m-nitroaniline), mL
Solution D (p-nitroaniline), mL
Total volume after dilution with ethyl acetate, mL
5.4.5.4 Determination and calculation of correction factor
Table 3 Preparation of standard mixed solution
Under the selected chromatographic conditions, add 2μL of the standard mixed solution respectively. After the peaks of each component have been eluted, calculate the correction factor of each component according to formula (2). The peak before p-nitrochlorobenzene is a low-boiling substance, and the correction factor is calculated according to p-nitrochlorobenzene; the peak after p-nitroaniline is a high-boiling substance, and the correction factor is calculated according to p-nitroaniline. The correction factor of each component is calculated according to formula (2): f
W| ...
GB/T4840.1—1999
1-Solvent, 2-Low boiling substances, 3-Nitrochlorobenzene, 4-Nitroaniline, 5-Nitroaniline, 6-Figure 1 Gas chromatogram of p-nitroaniline
5.4.6 Analysis steps
-P-nitroaniline; 7-High boiling substances
Weigh 0.5g (accurate to 0.01g) of p-nitroaniline (accurate to 0.01g) in a 10mL brown volumetric flask and dilute to the mark with ethyl acetate. Inject the sample under the selected conditions, and after the peaks of each component have been completely eluted, calculate the percentage of each component according to the peak area and relative correction factor of each component according to formula (3) and (4). See Figure 1 for the chromatogram. 5.4.7 Expression and calculation of results
The mass percentage of p-nitroaniline in dry product is calculated according to formula (3): fA.
W——the percentage of p-nitroaniline in dry product; correction factor of a component;
the peak area of a component, mm2;
W——the moisture content of p-nitroaniline in dry product. X(100-W)
The percentage of organic impurities in p-nitroaniline in dry product and damp product is calculated according to formula (4): x,=
W——the percentage of a component; f.—the correction factor of component i;
A——the peak area of component i, mm2.
·（3）
...........(4)
The difference between the two parallel determination results of purity shall not exceed 0.2%, and the difference between the two parallel determination results of each organic impurity content shall not exceed 0.05%. The arithmetic mean value shall be taken as the determination result. 5.5 Determination of moisture content
The moisture content of dry p-nitroaniline shall be carried out in accordance with the provisions of GB/T13753. Using chloroform + methanol = (3+1) as solvent, the difference between the two parallel 5
GB/T4840.1-1999
determination results shall not exceed 0.02%. The arithmetic mean value shall be taken as the determination result. Sample weight 0.5~1g. 6 Inspection rules
6.1 Inspection classification
All items specified in Table 1 are factory inspection items. 6.2 Inspection by the manufacturer
Para-nitroaniline shall be inspected by the quality inspection department of the manufacturer in accordance with the requirements of this standard. The manufacturer shall ensure that all products shipped out of the factory meet the requirements of this standard. Each batch of products shipped out of the factory shall be accompanied by a quality certificate in a certain format. 6.3 User acceptance
The user unit has the right to inspect the received para-nitroaniline products in accordance with the provisions of this standard to check whether they meet the requirements of this standard.
6.4 Re-inspection
If one of the indicators in the inspection results does not meet the requirements of this standard, samples shall be taken from twice the amount of packaging for re-inspection. If only one index does not meet the requirements of this standard in the re-inspection results, the entire batch of products cannot be accepted. 7 Marking, labeling, packaging, transportation and storage 7.1 Marking
The p-nitroaniline packaging barrel should have clear markings, indicating the manufacturer's name, address, product name, trademark, batch number, grade, gross weight, net weight and production date, and the word "toxic" and diagram according to the requirements of GB190 and GB191. 7.2 Labeling
Each batch of packaged products should be accompanied by a label of a certain format, which includes: manufacturer's name, address, product name, batch number, grade, net weight, production date, proof that the product quality meets the requirements of this standard and the number of this standard. 7.3 Packaging
Para-nitroaniline is packaged in woven bags or iron drums lined with plastic bags (plastic bags must be tied), with a net weight of 25kg per bag (barrel). If the user requires other packaging, it can be negotiated and determined.
7.4 Transportation
Prevent exposure to sunlight, collision and rain during transportation. 7.5 Storage
The product should be stored in a cool, dry and ventilated warehouse.8g0V-17 in a 100mL beaker, then add chloroform equivalent to the volume of 20g carrier. After it is completely dissolved, slowly pour in 20g carrier to make it completely soaked (about 10 minutes). Place the beaker in a fume hood and slowly evaporate the solvent under an infrared lamp until it is dry (the beaker should be tapped frequently to ensure that it is evenly coated). Then move it to a 90100℃ oven and dry it for about 30 minutes, then take it out for use. 5.4.3.3 Filling of the stationary phase
Plug the end of the chromatographic column connected to the detector with glass wool, wrap it with gauze, connect it to a vacuum pump, and connect the other end to a funnel. Slowly pour in the dried stationary phase under vacuum, tap the chromatographic column gently to make the filling even and tight. After filling, continue tapping for 5 to 10 minutes, plug the filled chromatographic column with glass wool, and prepare for aging.
5.4.3.4 Aging of chromatographic column
Install the filled chromatographic column into the column box of the chromatograph, without connecting a detector behind the column, and pass nitrogen at a flow rate of 5-10mL/min, and age at 270℃ for 8-10h.
5.4.4 Chromatographic conditions (optimal operating conditions can be selected according to different instruments) Column temperature: 220℃;
Vaporization temperature: 250℃;
Detection temperature: 250℃;
Carrier gas flow rate (N): 50mL/min;
Combustion gas flow rate (H2): 50mL/min;3
Auxiliary gas flow rate (O2): 500mL/min; Paper speed: 3mm/min;
Injection volume: 2~3μL;
Quantitative method: Peak area normalization method;
Resolution: ≥ 1.0
GB/T4840.1—1999
5.4.5 Preparation of standard stock solution and determination of correction factor 5.4.5.1 Reagents
Ethyl acetate;
p-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); o-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); m-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); p-Nitrochlorobenzene: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions). 5.4.5.2 Preparation of standard stock solution
According to the requirements of Table 2, weigh various reagents (accurate to 0.0002g) accurately into a clean and dry volumetric flask, dissolve with ethyl acetate, and dilute to the scale. The shelf life of the standard stock solution is three months. Table 2 Preparation of standard stock solution
Reagent name
Weighing amount, 8
Volume after dilution, mL
p-Nitrochlorobenzene
5.4.5.3 Preparation of standard mixed solution
Nitroaniline
m-Nitroaniline
p-Nitroaniline
In five numbered 10mL brown volumetric flasks, prepare according to Table 3 to obtain mixed solutions No. 1, 2, 3, 4, and 5. The shelf life of the standard mixed solution is one month.
Single calibration solution
Solution A (p-nitrochlorobenzene), mL
Solution B (o-nitroaniline), mL
Solution C (m-nitroaniline), mL
Solution D (p-nitroaniline), mL
Total volume after dilution with ethyl acetate, mL
5.4.5.4 Determination and calculation of correction factor
Table 3 Preparation of standard mixed solution
Under the selected chromatographic conditions, add 2μL of the standard mixed solution respectively. After the peaks of each component have been eluted, calculate the correction factor of each component according to formula (2). The peak before p-nitrochlorobenzene is a low-boiling substance, and the correction factor is calculated according to p-nitrochlorobenzene; the peak after p-nitroaniline is a high-boiling substance, and the correction factor is calculated according to p-nitroaniline. The correction factor of each component is calculated according to formula (2): f
W| ...
GB/T4840.1—1999
1-Solvent, 2-Low boiling substances, 3-Nitrochlorobenzene, 4-Nitroaniline, 5-Nitroaniline, 6-Figure 1 Gas chromatogram of p-nitroaniline
5.4.6 Analysis steps
-P-nitroaniline; 7-High boiling substances
Weigh 0.5g (accurate to 0.01g) of p-nitroaniline (accurate to 0.01g) in a 10mL brown volumetric flask and dilute to the mark with ethyl acetate. Inject the sample under the selected conditions, and after the peaks of each component have been completely eluted, calculate the percentage of each component according to the peak area and relative correction factor of each component according to formula (3) and (4). See Figure 1 for the chromatogram. 5.4.7 Expression and calculation of results
The mass percentage of p-nitroaniline in dry product is calculated according to formula (3): fA.
W——the percentage of p-nitroaniline in dry product; correction factor of a component;
the peak area of a component, mm2;
W——the moisture content of p-nitroaniline in dry product. X(100-W)
The percentage of organic impurities in p-nitroaniline in dry product and damp product is calculated according to formula (4): x,=
W——the percentage of a component; f.—the correction factor of component i;
A——the peak area of component i, mm2.
·（3）
...........(4)
The difference between the two parallel determination results of purity shall not exceed 0.2%, and the difference between the two parallel determination results of each organic impurity content shall not exceed 0.05%. The arithmetic mean value shall be taken as the determination result. 5.5 Determination of moisture content
The moisture content of dry p-nitroaniline shall be carried out in accordance with the provisions of GB/T13753. Using chloroform + methanol = (3+1) as solvent, the difference between the two parallel 5
GB/T4840.1-1999
determination results shall not exceed 0.02%. The arithmetic mean value shall be taken as the determination result. Sample weight 0.5~1g. 6 Inspection rules
6.1 Inspection classification
All items specified in Table 1 are factory inspection items. 6.2 Inspection by the manufacturer
Para-nitroaniline shall be inspected by the quality inspection department of the manufacturer in accordance with the requirements of this standard. The manufacturer shall ensure that all products shipped out of the factory meet the requirements of this standard. Each batch of products shipped out of the factory shall be accompanied by a quality certificate in a certain format. 6.3 User acceptance
The user unit has the right to inspect the received para-nitroaniline products in accordance with the provisions of this standard to check whether they meet the requirements of this standard.
6.4 Re-inspection
If one of the indicators in the inspection results does not meet the requirements of this standard, samples shall be taken from twice the amount of packaging for re-inspection. If only one index does not meet the requirements of this standard in the re-inspection results, the entire batch of products cannot be accepted. 7 Marking, labeling, packaging, transportation and storage 7.1 Marking
The p-nitroaniline packaging barrel should have clear markings, indicating the manufacturer's name, address, product name, trademark, batch number, grade, gross weight, net weight and production date, and the word "toxic" and diagram according to the requirements of GB190 and GB191. 7.2 Labeling
Each batch of packaged products should be accompanied by a label of a certain format, which includes: manufacturer's name, address, product name, batch number, grade, net weight, production date, proof that the product quality meets the requirements of this standard and the number of this standard. 7.3 Packaging
Para-nitroaniline is packaged in woven bags or iron drums lined with plastic bags (plastic bags must be tied), with a net weight of 25kg per bag (barrel). If the user requires other packaging, it can be negotiated and determined.
7.4 Transportation
Prevent exposure to sunlight, collision and rain during transportation. 7.5 Storage
The product should be stored in a cool, dry and ventilated warehouse.4 Chromatographic conditions (the best operating conditions can be selected according to different instruments) Column temperature: 220℃;
Vaporization temperature: 250℃;
Detection temperature: 250℃;
Carrier gas flow rate (N): 50mL/min;
Combustion gas flow rate (H2): 50mL/min;3
Auxiliary gas flow rate (O2): 500mL/min; Paper speed: 3mm/min;
Injection volume: 2~3μL;
Quantitative method: Peak area normalization method;
Resolution: ≥1.0|| tt||GB/T4840.1—1999
5.4.5 Preparation of standard stock solution and determination of correction factor 5.4.5.1 Reagents
Ethyl acetate;
p-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); o-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); m-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); p-Nitrochlorobenzene: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions). 5.4.5.2 Preparation of standard stock solution
According to the requirements of Table 2, accurately weigh various reagents (accurate to 0.0002g) in a clean and dry volumetric flask, dissolve with ethyl acetate, and dilute to the scale. The shelf life of the standard stock solution is three months. Table 2 Preparation of standard stock solution
Reagent name
Weighing amount, 8
Volume after dilution, mL
p-Nitrochlorobenzene
5.4.5.3 Preparation of standard mixed solution
Nitroaniline
m-Nitroaniline
p-Nitroaniline
In five numbered 10mL brown volumetric flasks, prepare according to Table 3 to obtain mixed solutions No. 1, 2, 3, 4, and 5. The shelf life of the standard mixed solution is one month.
Single calibration solution
Solution A (p-nitrochlorobenzene), mL
Solution B (o-nitroaniline), mL
Solution C (m-nitroaniline), mL
Solution D (p-nitroaniline), mL
Total volume after dilution with ethyl acetate, mL
5.4.5.4 Determination and calculation of correction factor
Table 3 Preparation of standard mixed solution
Under the selected chromatographic conditions, add 2μL of the standard mixed solution respectively. After the peaks of each component have been eluted, calculate the correction factor of each component according to formula (2). The peak before p-nitrochlorobenzene is a low-boiling substance, and the correction factor is calculated according to p-nitrochlorobenzene; the peak after p-nitroaniline is a high-boiling substance, and the correction factor is calculated according to p-nitroaniline. The correction factor of each component is calculated according to formula (2): f
W| ...
GB/T4840.1—1999
1-Solvent, 2-Low boiling substances, 3-Nitrochlorobenzene, 4-Nitroaniline, 5-Nitroaniline, 6-Figure 1 Gas chromatogram of p-nitroaniline
5.4.6 Analysis steps
-P-nitroaniline; 7-High boiling substances
Weigh 0.5g (accurate to 0.01g) of p-nitroaniline (accurate to 0.01g) in a 10mL brown volumetric flask and dilute to the mark with ethyl acetate. Inject the sample under the selected conditions, and after the peaks of each component have been completely eluted, calculate the percentage of each component according to the peak area and relative correction factor of each component according to formula (3) and (4). See Figure 1 for the chromatogram. 5.4.7 Expression and calculation of results
The mass percentage of p-nitroaniline in dry product is calculated according to formula (3): fA.
W——the percentage of p-nitroaniline in dry product; correction factor of a component;
the peak area of a component, mm2;
W——the moisture content of p-nitroaniline in dry product. X(100-W)
The percentage of organic impurities in p-nitroaniline in dry product and damp product is calculated according to formula (4): x,=
W——the percentage of a component; f.—the correction factor of component i;
A——the peak area of component i, mm2.
·（3）
...........(4)
The difference between the two parallel determination results of purity shall not exceed 0.2%, and the difference between the two parallel determination results of each organic impurity content shall not exceed 0.05%. The arithmetic mean value shall be taken as the determination result. 5.5 Determination of moisture content
The moisture content of dry p-nitroaniline shall be carried out in accordance with the provisions of GB/T13753. Using chloroform + methanol = (3+1) as solvent, the difference between the two parallel 5
GB/T4840.1-1999
determination results shall not exceed 0.02%. The arithmetic mean value shall be taken as the determination result. Sample weight 0.5~1g. 6 Inspection rules
6.1 Inspection classification
All items specified in Table 1 are factory inspection items. 6.2 Inspection by the manufacturer
Para-nitroaniline shall be inspected by the quality inspection department of the manufacturer in accordance with the requirements of this standard. The manufacturer shall ensure that all products shipped out of the factory meet the requirements of this standard. Each batch of products shipped out of the factory shall be accompanied by a quality certificate in a certain format. 6.3 User acceptance
The user unit has the right to inspect the received para-nitroaniline products in accordance with the provisions of this standard to check whether they meet the requirements of this standard.
6.4 Re-inspection
If one of the indicators in the inspection results does not meet the requirements of this standard, samples shall be taken from twice the amount of packaging for re-inspection. If only one index does not meet the requirements of this standard in the re-inspection results, the entire batch of products cannot be accepted. 7 Marking, labeling, packaging, transportation and storage 7.1 Marking
The p-nitroaniline packaging barrel should have clear markings, indicating the manufacturer's name, address, product name, trademark, batch number, grade, gross weight, net weight and production date, and the word "toxic" and diagram according to the requirements of GB190 and GB191. 7.2 Labeling
Each batch of packaged products should be accompanied by a label of a certain format, which includes: manufacturer's name, address, product name, batch number, grade, net weight, production date, proof that the product quality meets the requirements of this standard and the number of this standard. 7.3 Packaging
Para-nitroaniline is packaged in woven bags or iron drums lined with plastic bags (plastic bags must be tied), with a net weight of 25kg per bag (barrel). If the user requires other packaging, it can be negotiated and determined.
7.4 Transportation
Prevent exposure to sunlight, collision and rain during transportation. 7.5 Storage
The product should be stored in a cool, dry and ventilated warehouse.4 Chromatographic conditions (the best operating conditions can be selected according to different instruments) Column temperature: 220℃;
Vaporization temperature: 250℃;
Detection temperature: 250℃;
Carrier gas flow rate (N): 50mL/min;
Combustion gas flow rate (H2): 50mL/min;3
Auxiliary gas flow rate (O2): 500mL/min; Paper speed: 3mm/min;
Injection volume: 2~3μL;
Quantitative method: Peak area normalization method;
Resolution: ≥1.0|| tt||GB/T4840.1—1999
5.4.5 Preparation of standard stock solution and determination of correction factor 5.4.5.1 Reagents
Ethyl acetate;
p-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); o-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); m-Nitroaniline: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions); p-Nitrochlorobenzene: refined product (recrystallized from ethanol three times until no impurities are detected under the test conditions). 5.4.5.2 Preparation of standard stock solution
According to the requirements of Table 2, accurately weigh various reagents (accurate to 0.0002g) in a clean and dry volumetric flask, dissolve with ethyl acetate, and dilute to the scale. The shelf life of the standard stock solution is three months. Table 2 Preparation of standard stock solution
Reagent name
Weighing amount, 8
Volume after dilution, mL
p-Nitrochlorobenzene
5.4.5.3 Preparation of standard mixed solution
Nitroaniline
m-Nitroaniline
p-Nitroaniline
In five numbered 10mL brown volumetric flasks, prepare according to Table 3 to obtain mixed solutions No. 1, 2, 3, 4, and 5. The shelf life of the standard mixed solution is one month.
Single calibration solution
Solution A (p-nitrochlorobenzene), mL
Solution B (o-nitroaniline), mL
Solution C (m-nitroaniline), mL
Solution D (p-nitroaniline), mL
Total volume after dilution with ethyl acetate, mL
5.4.5.4 Determination and calculation of correction factor
Table 3 Preparation of standard mixed solution
Under the selected chromatographic conditions, add 2μL of the standard mixed solution respectively. After the peaks of each component have been eluted, calculate the correction factor of each component according to formula (2). The peak before p-nitrochlorobenzene is a low-boiling substance, and the correction factor is calculated according to p-nitrochlorobenzene; the peak after p-nitroaniline is a high-boiling substance, and the correction factor is calculated according to p-nitroaniline. The correction factor of each component is calculated according to formula (2): f
W| ...
GB/T4840.1—1999
1-Solvent, 2-Low boiling substances, 3-Nitrochlorobenzene, 4-Nitroaniline, 5-Nitroaniline, 6-Figure 1 Gas chromatogram of p-nitroaniline
5.4.6 Analysis steps
-P-nitroaniline; 7-High boiling substances
Weigh 0.5g (accurate to 0.01g) of p-nitroaniline (accurate to 0.01g) in a 10mL brown volumetric flask and dilute to the mark with ethyl acetate. Inject the sample under the selected conditions, and after the peaks of each component have been completely eluted, calculate the percentage of each component according to the peak area and relative correction factor of each component according to formula (3) and (4). See Figure 1 for the chromatogram. 5.4.7 Expression and calculation of results
The mass percentage of p-nitroaniline in dry product is calculated according to formula (3): fA.
W——the percentage of p-nitroaniline in dry product; correction factor of a component;
the peak area of a component, mm2;
W——the moisture content of p-nitroaniline in dry product. X(100-W)
The percentage of organic impurities in p-nitroaniline in dry product and damp product is calculated according to formula (4): x,=bZxz.net
W——the percentage of a component; f.—the correction factor of component i;
A——the peak area of component i, mm2.
·（3）
...........(4)
The difference between the two parallel determination results of purity shall not exceed 0.2%, and the difference between the two parallel determination results of each organic impurity content shall not exceed 0.05%. The arithmetic mean value shall be taken as the determination result. 5.5 Determination of moisture content
The moisture content of dry p-nitroaniline shall be carried out in accordance with the provisions of GB/T13753. Using chloroform + methanol = (3+1) as solvent, the difference between the two parallel 5
GB/T4840.1-1999
determination results shall not exceed 0.02%. The arithmetic mean value shall be taken as the determination result. Sample weight 0.5~1g. 6 Inspection rules
6.1 Inspection classification
All items specified in Table 1 are factory inspection items. 6.2 Inspection by the manufacturer
Para-nitroaniline shall be inspected by the quality inspection department of the manufacturer in accordance with the requirements of this standard. The manufacturer shall ensure that all products shipped out of the factory meet the requirements of this standard. Each batch of products shipped out of the factory shall be accompanied by a quality certificate in a certain format. 6.3 User acceptance
The user unit has the right to inspect the received para-nitroaniline products in accordance with the provisions of this standard to check whether they meet the requirements of this standard.
6.4 Re-inspection
If one of the indicators in the inspection results does not meet the requirements of this standard, samples shall be taken from twice the amount of packaging for re-inspection. If only one index does not meet the requirements of this standard in the re-inspection results, the entire batch of products cannot be accepted. 7 Marking, labeling, packaging, transportation and storage 7.1 Marking
The p-nitroaniline packaging barrel should have clear markings, indicating the manufacturer's name, address, product name, trademark, batch number, grade, gross weight, net weight and production date, and the word "toxic" and diagram according to the requirements of GB190 and GB191. 7.2 Labeling
Each batch of packaged products should be accompanied by a label of a certain format, which includes: manufacturer's name, address, product name, batch number, grade, net weight, production
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