Some standard content:
Chemical Industry Standard of the People's Republic of China
HG2026-91
O-Nitrotoluene
Published on June 27, 1991
Ministry of Chemical Industry of the People's Republic of China
Implemented on March 1, 1992
Chemical Industry Standard of the People's Republic of China
O-Nitrotoluene
Subject Content and Scope of Application
HG2026-91
This standard specifies the technical requirements, test methods, inspection rules, and marking, packaging, storage and transportation requirements for o-nitrotoluene. This standard applies to o-nitrotoluene obtained by fractionation of mixed nitrotoluene obtained by nitration of toluene. o-Nitrotoluene is mainly used in industries such as dyes, paints, plastics and medicines. Structural formula:
Empirical formula: CHNO2
Relative molecular mass: 137.14 (according to the international relative atomic mass in 1987)2
Cited standards
Dangerous goods packaging mark
General rules for gas chromatography of chemical reagents
GB9722
Technical requirements
O-nitrotoluene shall comply with the requirements of Table 1.
Indicator name
Melting point (thousand samples), ℃
O-nitrotoluene content, %(m/m）
M-nitrotoluene content, %(m/m）
Impurity content
Water content, %(m/m）
P-nitrotoluene content, %(m/m）
Low boiling matter content, %(m/m)
High boiling matter content, %(m/m)
Note: Water content and high boiling matter content are type inspection items. 4
Test method
Approved by the Ministry of Chemical Industry of the People's Republic of China on 1991-06-27>
Superior grade
Light yellow oily
Transparent liquid
First grade
Qualified grade
Transparent liquid from light yellow to light brown
Implemented on 1992-03-01
4.1 Determination of appearance
Determined by visual method.
4.2 Determination of Melting Point (Dry Product)
4.2.1 Apparatus
Melting point tester (Figure 1);
HG2026-91
Thermometer: a calibrated short-rod partial immersion or full immersion thermometer with a graduation value of 0.1℃, about 300mm long, and a temperature range of -10～10℃;
Test tube: inner diameter 14~15mm, about 120mm long; Cooling bath: 2L wide-mouth thermos or corresponding cooling bath; Stirrer: homemade stainless steel spiral stirrer. Figure 1 Melting point tester
1-Thermometer, 2-Stirrer, 3-Test tube, 4-Refrigerant, 5-Cooling bath 4.2.2 Reagents
4A or 5A spherical molecular sieve, roasted at 550℃ for 3h, placed in a desiccator for use; Refrigerant: ice + salt = 2+1 and appropriate amount of water. 4.2.3 Determination steps
4.2.3.1 Preparation of seed crystals
Take a dry test tube with an inner diameter of about 14mm and a length of about 120mm, add the dried o-nitrotoluene sample to 1/2 of the test tube volume, and insert the thermometer vertically into the sample. Place the test tube in an ice-salt cooling bath, and use a stirrer to continuously and rapidly stir the sample in the test tube until the sample is completely solidified (form crystallized) and the temperature rises immediately. When the temperature rises to the highest point and stays at this temperature for a period of time without rising, use this sample as a seed crystal (this seed crystal should be stored in a refrigerator or cooling bath for future use). 4.2.3.2 Determination of Samples
Put about 50mL of o-nitrotoluene sample in a dry 250mL wide-mouth bottle with a ground stopper, add 25g of 4A or 5A molecular sieve, cover the bottle cap and dry for 40 minutes (shake the sample bottle every 10 minutes), then pour the upper solution into the test tube to 1/2 of its volume, and insert the thermometer vertically into the test tube. Place the test tube in an ice-salt cooling bath, stir the sample rapidly with a stirrer, and when the sample cools to -6°C, use a glass rod to dip a small amount of seed crystals into the test tube, and then continue to stir the sample rapidly (at this time, the thermometer should keep the mercury ball 15mm away from the bottom of the test tube) until the sample is completely solidified (β-type crystal). When the temperature begins to rise, take out the test tube and continue to stir the sample. The temperature gradually rises and the sample begins to melt. When the temperature rises to a certain point and remains unchanged for a certain period of time, and the temperature at which the turbidity of the sample disappears is the melting point of o-nitrotoluene. 2
HG2026—91
If a full immersion thermometer is used, the melting point t is corrected according to formula (1): t-ti+At
At=0.00016h(ti-t2)
Where: △t is the correction value of the mercury column exposed outside the Great Wall, ℃; t is the observed melting point, ℃;
t is the ambient air temperature at the middle of the mercury column outside the Great Wall (measured by an auxiliary thermometer, the mercury ball of the auxiliary thermometer is located in the middle of the mercury column outside the Great Wall), ℃;
h is the height of the mercury column outside the Great Wall (expressed in thermometer scale); 0.00016 is the expansion coefficient of mercury in glass. The difference between the two measurement results should not be greater than 0.1℃, and the arithmetic mean is taken as the melting point of the sample. 4.3 Determination of o-nitrotoluene, m-nitrotoluene, p-nitrotoluene, low-boiling substances and high-boiling substances 4.3.1 Instruments
Gas chromatograph: should comply with the provisions of GB9722; Detector: hydrogen flame ionization detector; Recorder: full scale 10mV, response time 1s or data processor with this function; Chromatographic column: one stainless steel spiral column with diameter (g) 4mm, length (L) 2m and one stainless steel spiral column with diameter (g) 4mm, length (L) 0.5m; Micro syringe: 10uL.
4.3.2 Preparation of chromatographic column
4.3.2.1 Filler
Stationary liquid: polyethylene glycol adipate (PEGA); Carrier: 101 white carrier 0.180.25um (60~80 mesh); Liquid phase loading: 3/100.
4.3.2.2 Stationary liquid coating
Weigh 0.42g of stationary liquid (PEGA) into a 250mL beaker, add chloroform reagent equivalent to 14g of support volume, dissolve the stationary liquid under infrared lamp, slowly pour 14g of dried support into the beaker, place the beaker in a desiccator, keep it at a vacuum degree of about 7.99×10°Pa for 5-10min, take it out and place it in a fume hood, slowly evaporate the solvent until dry under infrared lamp (pat the beaker frequently) to make it evenly coated. 4.3.2.3 Filling method
Plug the detector end of the chromatographic column with a copper mesh, connect it to a vacuum pump, and connect the other end to a funnel. Slowly pour the stationary phase under a vacuum degree of about 7.99×10°Pa, and tap the chromatographic column until the stationary phase is no longer drawn into the column. Remove the chromatographic column and take out the copper mesh, add some stationary phase, plug the two ends of the chromatographic column with glass wool, and prepare for aging.
4.3.2.4 Chromatographic column aging
Put the filled chromatographic column into the chromatographic column box, pass nitrogen (flow rate is 5-20mL/min) and age it at 145℃ for 8h. 4.3.3 Chromatographic instrument operating conditions
Select the chromatographic operating conditions according to different instruments. Taking SP2305E gas chromatograph as an example, the operating conditions are as follows: 4.3.3.1 Chromatographic operating conditions for low boiling points, o-nitrotoluene, m-nitrotoluene and p-nitrotoluene: Column box temperature: 105±2°C (indicated on the meter); detector temperature: 200~220°C;
vaporization chamber temperature: 280~300°C;
carrier gas (N2) flow rate: 30mL/min;
fuel gas (H2) flow rate: 30mL/min;
air flow rate: 300~400mL/min,
amplifier sensitivity: 2×1;
injection volume: 0.4uL.
4.3.3.2 Chromatographic operating conditions for high boiling points
Column box temperature: 140℃ (indicated on the meter);
Injection volume: 1μL;
Other chromatographic operating conditions are the same as those specified in 4.3.3.1. HG2026—91
4.3.4 Preparation of calibration solutions and determination of relative correction factors 4.3.4.1
Toluene (GB684)
Nitrobenzene (HG3—963);
o-nitrotoluene: refined product;
m-nitrotoluene: chemically pure;
p-nitrotoluene: chemically pure;
2,4-dinitrotoluene: chemically pure;
4.3.4.2 Preparation of calibration solutions of low-boiling substances, o-nitrotoluene, m-nitrotoluene and p-nitrotoluene Weigh approximately 2 g (accurate to 0.0002g) in three 25mL volumetric flasks, dilute to scale with o-nitrotoluene (4.3.4.1c). Weigh about 1g (accurate to 0.0002g) of toluene (4.3.4.1a) in a 25mL volumetric flask, dilute to scale with o-nitrotoluene. In five numbered 10mL volumetric flasks, mix the above solutions according to Table 2 to obtain calibration solutions No. 1, No. 2, No. 3, No. 4, No. 5, respectively.
Table 2 Preparation of calibration mixed solution
Volume flask number
Amount of solution added, mL
Single standard solution
p-Nitrotoluene
m-Nitrotoluene
Nitrobenzene
Total volume after dilution with o-nitrotoluene
Note: o-nitrotoluene should be a pure product obtained through multiple distillations, or o-nitrotoluene after the impurity component content is accurately quantified using the external standard method, and its impurity content is calculated into the standard solution.
4.3.4.3 Determination of relative correction factor
After the operating conditions of the instrument are stable, take 0.4uL of calibration mixed solution No. 1, 2, 3, 4, and 5 respectively, inject it into the gasification chamber of the chromatograph, and wait until the peak is completed, and accurately measure the peak height of each component. Relative correction factor f of each component: Calculate according to formula (2): m,.ho
h,·mo
Where: m; mass of a component, g,bzxZ.net
h peak height of a component, mm;
mass of o-nitrotoluene, g;
peak height of o-nitrotoluene, mm.
Note: The relative correction factor of each component is recalibrated once a week, and the validity period of the standard solution is 1 month. 4.3.4.4 Preparation of high boiling point standard solution
Weigh about 0.5g (accurate to 0.0002g) of 2,4-dinitrotoluene (4.3.4.1f) in a 25mL volumetric flask and dilute to the scale with o-nitrotoluene (4.3.4.4
1c).
HG2026—-91
Pipette 0.2, 0.5, 1.0mL of the above solution into three 10mL volumetric flasks respectively, and dilute to the mark with o-nitrotoluene (4.3.4.1c). Then calculate the percentage concentration of 2,4-dinitrotoluene in the standard solution according to the mass of 2,4-dinitrotoluene. 4.3.5 Determination steps
4.3.5.1 Determination of o-nitrotoluene, m-nitrotoluene, p-nitrotoluene and low-boiling substances After all the operating conditions of the instrument are stable, pipette 0.4uL of the sample and inject it into the vaporization chamber of the chromatograph. After the peaks are completely discharged, accurately measure the peak height of each component (see Figure 2 for the chromatogram).
The percentage content X of each component is calculated according to formula (3): P,.f,.h,
X-(·f.·h)
X(100-X1-X2).
Where.—signal attenuation of a component;
f relative correction factor of a component;
h. peak height of a component, mm;
X1——water content, %;
—high boiling matter content, %;
The difference between the two parallel determination results of o-nitrotoluene content should not be greater than 0.2%. The difference between the two parallel determination results of m-nitrotoluene, p-nitrotoluene and low boiling matter should not be greater than 0.07%. 3
Figure 2 Spectrum of o-nitrotoluene
1-Toluene; 2-Nitrobenzene; 3-O-Nitrotoluene; 4-M-Nitrotoluene; 5-P-Nitrotoluene 4.3.5.2 Determination of high boiling point content
(3)
The determination of high boiling points is carried out on a 0.5m short column. After the operating conditions of the instrument are stable, 1uL of a standard solution with a dinitro content equivalent to that of the sample is injected into the vaporization chamber of the chromatograph, and the peak height is accurately measured after the peak is completely discharged. Then 1uL of o-nitrotoluene sample is injected into the vaporization chamber of the chromatograph, and the peak height is accurately measured after the peak is completely discharged, and the external standard method is used for quantification (see Figure 3 for the chromatogram). The percentage of high boiling matter X is calculated according to formula (4): C,·ho
Wherein: C——2,4-dinitrotoluene content in standard sample, %ho——2,4-dinitrotoluene peak height in sample, mm;-2,4-dinitrotoluene peak height in standard sample, mm. hs
4.4 Determination of moisture
4.4.1 Instrument
HG2026-91
Figure 3 Spectrum of dinitrotoluene in nitrotoluene
1-Nitrotoluene;2-2,4-dinitrotoluene KF-1 micro-water analyzer (equipped with 5mL micro-burette) or other micro-water analyzers with equivalent functions; Micro-syringe: 10uL.
4.4.2 Reagents
Methanol (GB683);
Pyridine (GB689);
Iodine (GB675);
Anhydrous sodium sulfite (HG3-1078): chemically pure; d.
Sulfuric acid (GB625): chemically pure;
Anhydrous sodium acetate (GB694);
Anhydrous sodium iodide: dry the sodium iodide at 120℃ and store it in a sealed bottle; Sulfur dioxide: sulfur dioxide in a steel cylinder or obtained by decomposing sodium sulfite with concentrated sulfuric acid. 4.4.3 Preparation and calibration of Karl Fischer reagent (or improved reagent) 4.4.3.1 Preparation of Karl Fischer reagent
Put 85g iodine (4.4.2c) in a dry, 1L, stoppered brown narrow-necked bottle, add 670mL methanol (4.4.2a), plug the bottle, and shake until the iodine is completely dissolved. Then add 270mL pyridine (4.4.2b) and shake well. Connect according to Figure (4) and pass about 65g sulfur dioxide gas into this solution (a slight excess of sulfur dioxide will not be a problem). When passing sulfur dioxide, use an ice water bath to cool the solution to ensure that the solution temperature does not exceed 20℃. Place the solution in a dark place for at least 24h before use. 4.4.3.2 Preparation of Karl Fischer modified reagent Place 63g iodine (4.4.2c) in a dry, 1L brown narrow-necked bottle with a stopper, add 600mL methanol (4.4.2a), then add 25g anhydrous sodium iodide and 85g anhydrous sodium acetate (4.4.2f), plug the bottle, and shake until the iodine and other ingredients are completely dissolved (liquid A). According to Figure 4, pass sulfur dioxide (the solution temperature does not exceed 20℃) into a stoppered bottle containing no less than 90mL methanol and cooled in an ice-water bath, so that the sulfur dioxide concentration c(SO) = 4mol/L (256g/L) (liquid B). Add 90mL of solution B (containing sulfur dioxide 23) to solution A, or directly pass about 23g dry sulfur dioxide gas into solution A cooled in an ice bath (the solution temperature does not exceed 20℃), then dilute to 1L with methanol, mix well, and place in a dark place for later use. 6
HG2026-91
4.4.3.3 Calibration of the titer of Karl Fischer reagent (or improved reagent) Use a 10uL microsyringe to draw up 5uL of water, weigh its mass (accurate to 0.0002g), repeat twice, and take the arithmetic mean as the mass of 5uL of water.
Add 25mL of chloroform-methanol (3+1) mixed solvent into the reactor, cover the bottle stopper, connect the power supply, start the electromagnetic stirrer, and titrate the water in the solvent with Karl Fischer reagent (or improved reagent) until the ammeter pointer produces a large deflection and remains unchanged for 1 minute as the end point (do not record the volume of the reagent consumed).
Use a 10uL microsyringe to inject 5uL of water into the reactor, cover the bottle stopper and continue to titrate with Karl Fischer reagent (or improved reagent) until the ammeter pointer stays at the same position as the blank titration, and remains unchanged for 1 minute as the end point. The titer T of Karl Fischer reagent (or improved reagent) is calculated according to formula (5): Tmi
Where: m1——the mass of water, mg;
Vi——the volume of Karl Fischer reagent (or improved reagent) consumed, mL. Note: The titer should be calibrated every day.
Figure 4 Karl Fischer reagent preparation device
1 Sulfur dioxide generator; 2-concentrated sulfuric acid filter; 3-separator; 4 Absorption bottle containing iodine pyridine solution; 5-ice bath 4.4.4 Determination steps
Put 25mL of chloroform-methanol (3+1) mixed solvent in the reactor and cover the bottle stopper. Connect the power supply, start the electromagnetic stirrer, and use Karl Fischer reagent (or improved reagent) to titrate the water in the solvent until the ammeter pointer has a large deflection and remains unchanged for 1min (the volume of the reagent consumed is not counted), add 2-5 (accurate to 0.1g) o-nitrotoluene sample to the reactor, cover the bottle stopper, wait until the sample is completely dissolved, and use Karl Fischer reagent (or improved reagent) to titrate until the ammeter pointer stays at the same position as the blank titration, and remain unchanged for 1min as the end point. The moisture content X1 is calculated according to formula (6): V.·T
X1-m2×1000
Where: V3-volume of Karl Fischer reagent (or improved reagent) consumed in titrating the sample, mL;-titration of Karl Fischer reagent (or improved reagent), mg/mL; T
m2mass of sample, g.
The difference between the results of two parallel determinations shall not exceed 0.03%, and the arithmetic mean shall be taken as the determination result. Note: Karl Fischer reagent is used for arbitration analysis. 5 Inspection rules
5.1 o-Nitrotoluene shall be inspected by the technical inspection department of the manufacturer, and the manufacturer shall ensure that all o-nitrotoluene shipped out of the factory meets the requirements of this standard. Each batch of o-nitrotoluene shipped out of the factory shall be accompanied by a quality certificate in a certain format. 5.2 The user has the right to verify the quality of the o-nitrotoluene received in accordance with the provisions of this standard to verify whether it meets the requirements of this standard.
HG2026—91
5.3 Sampling method: Select 10% of the barrels from each batch (a batch of uniform products) for sampling. The sampling of small batches of products shall not be less than 5 barrels. When sampling, use a glass tube with a diameter of 13mm and a length of 1m with a thinner end to take samples from the upper, middle and lower parts of the opened barrel. The total amount of the sample taken shall not be less than 500mL.
5.4 Mix the selected samples carefully and put them into a clean, dry glass bottle with a ground stopper. A label shall be attached to the bottle, indicating: manufacturer name, product name, batch number and sampling date. Inspection shall be carried out by the inspection department. 5.5 If one of the indicators in the inspection results does not meet the requirements of this standard, a sample of o-nitrotoluene shall be selected from twice the amount of packaging for re-inspection. If even one indicator of the re-inspection result does not meet the requirements of this standard, the entire batch of o-nitrotoluene cannot be accepted. 5.6 When the supply and demand parties have disputes over product quality and need arbitration, the arbitration institution may be determined by agreement between the two parties. During arbitration, arbitration analysis shall be conducted in accordance with the sampling method and inspection method specified in this standard. 6 Packaging, marking, storage and transportation
6.1 Ortho-nitrotoluene is packaged in 100 or 200L iron drums, and the thickness of the iron sheet shall not be less than 1.2mm. The net weight of each drum is 100 or 200kg. 6.2 Each batch of products shipped shall be accompanied by a quality certificate. The certificate shall include the manufacturer's name, product name, batch number, grade, production and delivery date, product net weight, proof that the product quality meets the requirements of this standard and the number of this standard. 6.3 The packaging container shall be painted with a firm mark, which includes: manufacturer's name, registered trademark, product name, grade, production date, batch number and net weight, and the "toxic" mark shall be marked in accordance with the provisions of GB190 "Dangerous Goods Packaging Marking". 6.4 It is not allowed to approach fire sources during transportation and storage. It should be placed in a cool place and handled with care. 6.5 Because the product is toxic, it should not come into contact with the skin during use and handling, and labor protection equipment should be worn to prevent poisoning. Additional notes:
This standard was proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the technical jurisdiction of the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. This standard was drafted by the Dye Factory of Jilin Chemical Industry Company of the Ministry of Chemical Industry. The main drafters of this standard are Li Shulan, Zhang Huiren and Lin Jun. This standard refers to the Japanese Industrial Standard JISK4108-81 "Nitrobenzene". 8
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.