Some standard content:
Chemical Industry Standard of the People's Republic of China
HG2610-94
2-Methyl-4-chlorosodium
Published on April 4, 1994
Ministry of Chemical Industry of the People's Republic of China
Implementation on October 1, 1994
Chemical Industry Standard of the People's Republic of China
Sodium 4-chloro-2-methyl-4-chloro
Other names, structural formulas and basic physicochemical parameters of sodium 4-chloro-2-methyl-4-chloro are as follows: ISO common name: MCPA-Na
Trade name: Sodium 4-chloro-2-methyl-4-chloro
CIPAC digital code: 2.1
Chemical name: Sodium 4-chloro-2-methylphenoxyacetic acid Structural formula:
Empirical formula: C.HO:CINa
OCH2COONa
Relative molecular mass: 222.6 (according to the international relative atomic mass in 1989) Biological properties: Hormone herbicide.
Melting point (2-methyl-4-chlorophenoxyacetic acid): 118~119℃. Solubility: easily soluble in water. The solubility of 2-methyl-4-chlorophenoxyacetic acid in water (20℃) is 8.25mg/L. HG2610-94
Replaces HG2-1460-82
Stability: easy to absorb moisture, but the active ingredient 2-methyl-4-chlorophenoxyacetic acid does not degrade. This product has good storage stability. Subject content and scope of application
This standard specifies the technical requirements, test methods, inspection rules and markings, packaging, transportation and storage of 2-methyl-4-chloro sodium. This standard applies to 2-methyl-4-chloro sodium made from o-cresol and monochloroacetic acid. 2 Reference standards
GB/T601 Preparation of standard solution for titration analysis (volume analysis) of chemical reagents GB/T1604 Acceptance rules for pesticides
GB/T1605 Sampling methods for commercial pesticides
GB3796 General rules for pesticide packaging
3 Technical requirements
3.1 Appearance
2-Methyl-4-chlorosodium is reddish brown or dark brown powder. 3.22-Methyl-4-chlorosodium shall meet the following index requirements: Approved by the Ministry of Chemical Industry of the People's Republic of China on April 4, 1994, and implemented on October 1, 1994
2-Methyl-4-chlorosodium content (on dry basis),
Free phenol content (on 4-chloro-o-cresol), loss on drying:
Water insoluble matter\
Note: 1) At least once a month for inspection.
4 Test method
HG2610—94
%(m/m)
Unless otherwise specified, the reagents used in this test are all analytically pure, and the water should comply with the third-grade water in GB/T6682: if the solvent is not specified, the solution is an aqueous solution.
4.12 Determination of sodium 2-methyl-4-chlorophenoxyacetate
4.1.1 Identification test
4.1.1.1 Gas chromatography: This identification test can be carried out simultaneously with the determination of sodium 2-methyl-4-chlorophenoxyacetate content. The relative difference between the retention time of the main (chromatographic) peak of the sample solution and the retention time of methyl 2-methyl-4-chlorophenoxyacetate of the standard solution under the same conditions should be within 1.5%. 4.1.1.2 Infrared spectroscopy: Infrared scanning is performed in the range of 400 to 4000 cm-1. There should be no obvious difference between the infrared spectra of the sample and the standard.
4.1.22 Determination of 4-chloro-2-methyl-1-phenoxyacetic acid content
4.1.2.1 Summary of method
The sample was derivatized with diazomethane, and dimethyl phthalate was used as the internal standard. A stainless steel column filled with 5% Apizone L/101 white silanized carrier (180-250um) was used as the filler and a hydrogen flame detector was used to chromatographically separate and determine 4-chloro-2-methyl-1-phenoxyacetic acid. 4.1.2.2 Reagents and solutions
Ether (GB12591-90);
Potassium hydroxide (GB/T2306);
Hydrochloric acid (GB/T622);
Sulfuric acid (GB/T625);
Sodium nitrite (GB/T633);
Urea (GB/T696);
Methylamine hydrochloride;
Acetone (GB/T686);
Chloroform (GB/T682);
Anhydrous ethanol (GB/T678);
2-Methyl-4-chlorophenoxyacetic acid standard sample: known content ≥99. 0% (m/m); internal standard dimethyl phthalate, which should not contain impurities that interfere with the analysis; stationary liquid: Apizone L;
carrier: 101 white silanized carrier, 180~250um; saturated solution of diazomethane ether Take 10mL of 50% potassium hydroxide aqueous solution and 5mL of ether in a 20mL test tube, add 0.5~1g of α-nitroso-α-methylurea prepared according to Appendix A (Supplement) in a fume hood, and absorb the released diazomethane gas with a ground-mouth bottle containing 100mL of ether until the solution turns yellow and excess diazomethane bubbles escape, which means that saturation is achieved (the above tests are required to be carried out in an ice water bath). The prepared diazomethane should be sealed and stored at low temperature. 4.1.2.3 Instruments
Gas chromatograph: with hydrogen flame ionization detector; chromatographic processor (or recorder, full scale 5mV); chromatographic column: 2mX4mm (ID) stainless steel column; HG261094
Column filling: Apisone L coated on 101 white silanized carrier (180-250um). Solid liquid: carrier = 5:100 (m/m). 4.1.2.4 Preparation of chromatographic column
a. Coating of stationary liquid
Weigh 0.5g of Apisone L, put it in a beaker, add an appropriate amount of chloroform (just enough to immerse the carrier to be coated), and stir to completely dissolve it. Then weigh 10g of 101 white silanized carrier and pour it into the above solution, gently stir and mix evenly. Bake under an infrared lamp and shake from time to time until the solvent is completely evaporated, and store it in a stoppered container for later use. b. Filling of chromatographic column
Connect a small funnel to the outlet of the washed and dried chromatographic column, and fill the prepared filler into the column in batches, while constantly tapping the column wall until it is filled to 1.5 cm from the column outlet. Move the funnel to the inlet of the chromatographic column, plug a ball of silanized glass wool at the outlet, connect it to the vacuum pump through a rubber tube, turn on the vacuum pump, continue to slowly add the filler, and constantly tap the column wall to make it evenly and tightly filled. After filling, also plug a small ball of glass wool at the inlet end and press it appropriately to keep the column filler from moving. Aging of chromatographic column
Connect the inlet end of the chromatographic column to the vaporization chamber, do not connect the detector at the outlet end, pass the carrier gas (N2) at a flow rate of 20 mL/min, and heat it to 220°C in stages. At this temperature, age for at least 48 hours. 4.1.2.5 Gas chromatography operating conditions
Temperature: column chamber 180±10℃; vaporization chamber 240℃; detector chamber 250℃. Gas flow rate: carrier gas (Nz) 30mL/min; hydrogen 30mL/min, air 300mL/min. Injection volume: 0.5~1uL
Relative retention value (see the table below):
2-methyl-4-chlorophenoxyacetic acid methyl ester
dimethyl phthalate
2-methylbenzeneoxyacetic acid methyl ester
6-chloro-2-methylbenzeneoxyacetic acid methyl ester
4,6-dichloro-2-methylbenzeneoxyacetic acid methyl ester
The above operating conditions are typical operating parameters; according to the characteristics of different instruments, the given operating parameters can be appropriately adjusted to obtain the best effect.
4.1.2.6 Determination steps
a. Preparation of standard solution
Weigh 0.1g of 2-methyl-4-chlorobenzene standard (accurate to 0.0002g) and place it in a 25mL beaker; weigh 0.06g of internal standard (accurate to 0.0002g), dissolve it in 10mL of ether and mix well. Take 2mL of this solution in a measuring cylinder, add excess diazomethane ether solution (about 6mL) for esterification, transfer it to a stoppered small glass bottle, and concentrate it to about 0.5mL. b. Preparation of sample solution
Weigh 0.2g of 2-methyl-4-chlorobenzene sodium sample (accurate to 0.0002g), placed in a 100mL beaker, add 10mL distilled water to dissolve it completely, shake and drop 1+1 hydrochloric acid solution to convert 2-methyl-4-chloro-sodium into 2-methyl-4-chloro-acid and precipitate. Transfer all the contents of the beaker into a separatory funnel, rinse the beaker with 20mL ether 2-3 times, and add the washing liquid into the separatory funnel. Fully shake the separatory funnel and let it stand for 5-10 minutes to separate. Separate the lower water layer into the second separatory funnel, add 15mL ether and repeat the above operation for the second extraction. After standing and separating, separate the water layer into the third separatory funnel and extract it for the third time with 10mL ether. After discarding the water layer, combine the ether layers in the second and third separatory funnels into the first separatory funnel, rinse the second and third separatory funnels with 5mL ether, and the washing liquid is also combined in the first funnel.
HG2610—94
Weigh 0.06g of internal standard (accurate to 0.0002g), add it to the first separatory funnel, shake well, take 4mL of test solution into a 20mL test tube, shake in a fume hood, and drop 6-8mL of saturated diazomethane ether solution to completely esterify the sample. Use the same treatment method as the standard sample to concentrate the sample solution to 0.5mL. c. Determination
Under the operating conditions of 4.1.2.5, after the instrument is basically stable, continuously inject several needles of standard solution, calculate the repeatability of the relative response value of each needle, and when the relative response value of two adjacent needles is less than 1.5%, perform gas chromatography analysis in the following order: standard solution, sample solution, sample solution, standard solution. Gas chromatogram of 2-methyl-4-chloro-1-methyl-2-yloxy-1-methyl-3-nitropropene
1 ether; 2-—2-methyl-2-chloro-1-methyl-2-nitropropeneoxy-acetic acid methyl ester; 3-dimethyl phthalate; 4-6-chloro-2-methyl-2-methyl-2-nitropropeneoxy-acetic acid methyl ester; 5-2-methyl-4-chloro-1-methyl-2-methyl-2-nitropropeneoxy-acetic acid methyl ester; 6-4,6-dichloro-2-methyl-2-methyl-2-nitropropeneoxy-acetic acid methyl ester 4
4.1.2.7 Calculation
HG2610—94
Average the ratios of the peak areas (peak heights) of 2-methyl-4-chloro-1-methyl-2-yloxy-1-methyl-2-nitropropene to the internal standard in the two sample solutions and the two standard solutions before and after the sample. The mass percentage content of sodium 2-methyl-4-chloride X1 (dry basis conversion) is calculated according to formula (1): X
T2mimy2
1. ma m2 . (1 -X) X 1.11
Wherein: - the average value of the peak area (peak height) ratio of 2-methyl-4-chloride to the internal standard in a standard solution; - the average value of the peak area (peak height) ratio of 2-methyl-4-chloride to the internal standard in a sample solution; r2
-the mass of the 2-methyl-4-chloride standard, g;
-the mass of the internal standard in the 2-methyl-4-chloride standard, g; m2
ma——the mass of the 2-methyl-4-chloride sample, g;
m4——the mass of the internal standard in the 2-methyl-4-chloride sample, g; p—the percentage content of the 2-methyl-4-chloride standard (m/m); X. ——Loss on drying, % (m/m);
1.11—Ratio of relative molecular mass of 2-methyl-4-chlorosodium to 2-methyl-4-chloroacid. 4.1.2.8 Allowable difference
The difference between two parallel determination results shall not exceed 1.2% (m/m). 4.2 Determination of free phenol content
4.2.1 Summary of method
Dissolve the sample in alcohol-ammonia solution, add 4-aminophenazone and potassium hexacyanoferrate solution, and then determine the absorbance of the sample in the ethanol-ammonia solution.
4.2.2 Reagents and solutions
Ammonia solution: 0.05mol/L;
Ethanol (GB/T678);
Solution A: Dissolve 100mg 4-chloro-o-cresol in 10mL acetone, dilute to 1000mL with water (1mL=0.1mg free phenol); Solution B: Dissolve 0.5g 2-methyl-4-chlorosodium in 50mL ethanol, add 90mL 0.05mol/L ammonia solution, dilute to 1000mL with water,
4-aminophenazone: 2g aqueous solution, prepared from 20g/L stock solution. The stock solution can be stored in a dark place for less than three months. Potassium hexacyanoferrate: 4g aqueous solution, prepared when used. 4.2.3 Instruments
Spectrophotometer: 520nm,
Microburette: 2mL;
Pipette: 5mL, 10mL;
Colorimetric tube: 25mL, 7 pcs,
Volume flask: 1000mL, 3 pcs.
4.2.4 Operation steps
a. Calibration
Use a microburette to transfer 0.2, 0.4, 0.5, 0.6, 0.8, 1.0 and 1.2mL of solution A to seven colorimetric tubes respectively, dilute to 10mL with solution B respectively, add 5mL of ammonia solution and 5mL of 4-aminophenazone solution, mix, then add 5mL of potassium hexacyanoferrate solution, shake vigorously for 1min, let stand for 5-10min, and then use a 1cm colorimetric cell and water as reference to measure the absorbance. For blank reagent determination, take 10mL of solution B, treat it with ammonia solution, 4-aminophenazone solution and potassium hexacyanoferrate solution according to the above requirements and then determine it. Subtract the blank from the reading obtained from the phenol solution, and draw a calibration curve of the volume (mL) of solution A against the absorbance. b. Determination of free phenol in the sample
Weigh 0.2g of 2-methyl-4-chlorosodium sample (accurate to 0.0002g), place it in a 1000mL volumetric flask, add 50mL of ethanol to dissolve it, then add 5
HG2610—94
90mL of ammonia solution, and dilute it to 1000mL with water. Use a pipette to transfer 10mL of the solution to a colorimetric tube, and add 5mL of ammonia solution, 5mL of 4-aminophenazone and 5mL of potassium hexacyanoferrate solution in turn. Each solution should be shaken. Continue shaking for about 1min, and after standing for 5-10min, determine its absorbance. Prepare and measure the absorbance of the blank solution, and deduct it from the absorbance of the sample solution. Find the volume of solution A with the corresponding absorbance value from the curve.
4.2.5 Calculate
The mass percentage of free phenol X2 is calculated according to formula (2): Xz
Where: V—volume of solution A found from the curve, mL (1 mL = 0.1 mg free phenol); sample mass, g.
4.3 Determination of loss on drying
4.3.1 Apparatus
Weighing bottle: flat, 70×20 mm;
Oven;
Dryer.
4.3.2 Operation steps
（2）
Weigh 5g of 2-methyl-4-chlorosodium sample (accurate to 0.001g), place it in a weighing bottle that has been dried to constant weight, dry it at 105±2℃ for 1h, take it out and place it in a desiccator, cool it to room temperature, and weigh it. 4.3.3 Calculate
The drying loss mass percentage X3 is calculated according to formula (3): ml-mz×100
Where: m1——the mass of the weighing bottle and sample before putting it into the oven,; m2——the mass of the weighing bottle and sample after drying for 1h, g; one mass of the sample,.
4.4 Determination of water-insoluble matter
4.4.1 Apparatus
G3 acid-resistant filter funnel: 40mL;bzxZ.net
oven;
desiccator.
4.4.2 Operation steps
Weigh 5g (accurate to 0.001g) of 2-methyl-4-chlorosodium sample and place it in a 250mL beaker. Add 200mL of distilled water to dissolve it. Heat it to boiling in an electric furnace while stirring continuously to completely dissolve the water-soluble substances. Then filter it while hot using a G3 acid-resistant filter funnel that has been dried to constant weight. Transfer all insoluble substances into the funnel. Wash the precipitate three times with distilled water (about 20mL each time) and filter it until it is almost dry. Place the funnel in an oven at 105±2℃ and dry it for 2h. After taking it out, place it in a desiccator, cool it to room temperature, and weigh it. 4.4.3 Calculate the mass percentage X of water-insoluble matter according to formula (4): X = m1 = m2 × 100
Wherein: m1 - the mass of G3 acid-resistant filter funnel and water-insoluble matter after drying for 2 hours, g; m2 - the mass of G3 acid-resistant filter funnel, g; m
- the mass of the sample.
5 Inspection rules
5.1 Sampling method
HG2610-94
Sampling shall be carried out according to the "Technical Drug Sampling Method" in GB/T1605. The number of packages to be sampled shall be determined by random method; the final sampling volume shall not be less than 250g.
5.2 Acceptance rules
Acceptance shall be conducted in accordance with GB/T1604
Marking, packaging, transportation and purchase and storage
6.12 The packaging and marking of sodium 4-chloromethyl chloride shall comply with the relevant provisions of GB3796 and shall be marked with trademarks. 6.22 Sodium 4-chloromethyl chloride is packaged in 1kg and 0.5kg plastic bags, and is packaged in cartons or calcium plastic boxes. The net weight of each box is 20kg, and the product manual is attached to the box. The manufacturer name, product name, product standard number, batch number, net weight, pesticide registration number, production license number, trademark, etc. shall be indicated on the box. 6.3 According to the user's requirements or the agreement reached between the supply and demand parties, other forms of packaging can be used, but they must comply with the relevant provisions of GB3796. 6.4 During storage and transportation, strictly prevent moisture and sunlight, do not mix with food, seeds and feed, avoid contact with skin and eyes, and prevent inhalation through the mouth and nose. 6.5 The package should be stored in a ventilated and dry warehouse. 6.6 Safety: In addition to the corresponding toxicity mark, there should also be toxicity instructions, precautions for use, detoxification methods and rescue measures on the instruction manual or packaging container.
This product is irritating to the eyes. After splashing, rinse with plenty of water and use medication. It is toxic if swallowed or inhaled. Protective equipment should be worn when using this product. When spraying, avoid sprinkling on sensitive crops such as grapes, tomatoes, cotton, etc. 6.7 Warranty period: Under the specified storage and transportation conditions, the warranty period of 2-methyl-4-chloro-sodium is at least two years from the date of production. During the warranty period, the content of active ingredients still meets the standard requirements. 7
HG2610—94
Appendix A
Preparation of α-nitroso-α-methylurea
(Supplement)
Weigh 106.6 g (1.5 mol) of methylamine hydrochloride (95%) and place it in a 1000 mL round-bottom flask. Add water to make the total amount 500 g, then add 300 g of urea (5 mol). Under reflux, react the solution gently for 2 h 45 min, then reflux vigorously for 15 min. After the solution is cooled to room temperature, add 110 g (1.5 mol) of sodium nitrite, and cool the entire solution to 0°C. Put 600g water and 100g concentrated sulfuric acid in a 3000mL beaker, cool the beaker with ice-salt water mixture, and slowly add the cooled α-nitroso-α-methyl thiazide solution to the sulfuric acid with a separatory funnel while stirring continuously. During the addition, the temperature should not exceed zero degrees.
α-nitroso-α-methyl thiazide forms crystalline foam (light orange) suspended on it, which is filtered with a Buchner funnel and washed twice with 50mL of water. The orange crystals are placed in a desiccator and then put in a refrigerator for later use. Additional remarks:
This standard was proposed by the Technical Supervision Department of the Ministry of Chemical Industry. This standard is under the technical jurisdiction of the Shenyang Chemical Research Institute of the Ministry of Chemical Industry. This standard was drafted by Fushun Pesticide Factory, and Shijiazhuang Chemical Factory participated in the drafting. The main drafters of this standard are Wang Wenyu, Lu Li, Hou Yukai, Yu Junsheng, Wang Yi, and Wang Shuhui.
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