Some standard content:
HG3627—1999
Cypermethrin is a synthetic pyrethroid insecticide with contact and stomach poisoning effects, a wide insecticide spectrum, and is widely used in agriculture and health.
The technical requirements of this standard refer to the United Nations Food and Agriculture Organization (FAO) pesticide specifications [FAOSpecification332/TC/S/F (1993)], and stipulate the appearance, total content, moisture, and acidity of cypermethrin technical materials, with indicators close to them; at the same time, the cis-isomer content indicator in the FAO pesticide specifications is changed to the ratio of high-efficiency and low-efficiency isomers; and the warranty period is increased. The determination method of the total content of cypermethrin in this standard refers to the International Pesticide Analysis Cooperation Council CIPAC332/TC/(M)/3.2, and the mobile phase is changed from sub-(isooctane: ethyl acetate) = 99.5:0.5 to sub-(n-hexane: ethyl acetate) 99:1. This standard replaces the chemical industry standard HG/T2987-1988 "Analysis Method for Cypermethrin Content" from the date of implementation. Appendix A of this standard is the appendix of the standard. This standard is proposed by the Policy and Regulations Department of the State Administration of Petroleum and Chemical Industry. This standard is under the technical jurisdiction of Shenyang Chemical Research Institute. The main drafting unit of this standard: Shenyang Chemical Research Institute. The participating drafting units of this standard: Tianjin Longdeng Chemical Co., Ltd., Nanjing No. 1 Pesticide Factory, Jiangsu Yangnong Chemical Group Co., Ltd. The main drafters of this standard: Xu Laiwei, Zhang Xuebing, Lou Shaowei, Zou Lidong, Fan Wenzhong, Wang Quanzhong. 1238
Chemical Industry Standard of the People's Republic of China
Cypermethrin Technical
Cypermethrin technical
Other names, structural formulas and basic physical and chemical parameters of cypermethrin are as follows:ISO common name: Cypermethrin
CIPAC digital code: 332
HG3627—1999
Replace HG/T 2987—1988
Chemical name: (RS)-α-cyano-3-phenoxybenzyl (1RS)-cis-trans-3-2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate
Structural formula:
CI,C—CH—CH—CH-
Empirical formula: C22H1.Cl,NO
Relative molecular mass: 416.31 (according to the 1993 international relative atomic mass) Biological activity: insecticide|| tt||Vapor pressure (20℃): 190nPa
Solubility (g/L, 20℃): 1×10-5～2×10-4 in water, 103 in hexane; 337 in ethanol, greater than 450 in acetone, chloroform, cyclohexanone, and xylene
Stability: Stable at 220℃, neutral or acidic conditions, best at pH-4, degradation range of 1 in soil
This standard specifies the requirements, test methods, and marking, labeling, packaging, storage and transportation of cypermethrin technical. This standard applies to cypermethrin technical composed of azomethrin and impurities generated during its production. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard by being referenced in this standard. When this standard is published, the versions shown are all valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T601-1988 Preparation of standard solutions for titration analysis (volume analysis) of chemical reagents GB/T1600—1979 (1989) Method for determination of moisture content in pesticides GB/T1604--1995 Acceptance rules for commercial pesticides GB/T1605--1979 (1989) Method for sampling commercial pesticides GB3796--1983 General rules for pesticide packaging
GB4838—1984 Packaging of emulsifiable pesticides
GB/T9008—1988 Terminology for liquid chromatography Column liquid chromatography and planar chromatography
Approved by the State Administration of Petroleum and Chemical Industry on June 16, 1999 Implemented on June 1, 2000
3 Requirements
HG 3627—1999
3.1 Appearance: Yellow to brown viscous liquid or semi-solid with crystals, no visible foreign impurities. 3.2 Cypermethrin technical shall meet the requirements of Table 1. Table 1 Control Items of Cypermethrin Technical
Total content of cypermethrin, %
Acidity (in H2SO,), %
High-efficiency and low-efficiency isomer ratio
Superior product
Note: The high-efficiency and low-efficiency isomer ratio is a reference item and is not used as a basis for judging qualification. 4 Test Method
4.1 Sampling
First-class product
Qualified product
The sampling method of "sampling of emulsion and liquid state" in GB/T1605--1979 (1989) shall be followed. Before sampling, the cypermethrin technical shall be heated to 55~60℃ to melt and mix it. The sampled packages are determined by the random number table method, and the final sample volume should be no less than 250 mL. 4.2 Identification test
4.2.1 High performance liquid chromatography: This identification test can be carried out simultaneously with the determination of the total content of flumethrin. Under the same chromatographic operating conditions, the retention time of the four chromatographic peaks of the test solution and the retention time of the four chromatographic peaks corresponding to the cypermethrin in the standard solution should have a relative difference within 1.5%.
4.2.2 Infrared spectroscopy: There should be no obvious difference in the infrared spectra of the test sample and the standard sample in the wave number range of 4000 to 400 cm-1 (see Figure 1).
4.3 Determination of Cypermethrin Content
4.3.1 Method Summary
Figure 1 Infrared spectrum of cypermethrin standard The sample was dissolved in ethyl acetate/n-hexane mixed solvent containing methyl benzoate (internal standard). The ethyl acetate/n-hexane mixed solvent was used as the mobile phase. Normal phase liquid spectroscopy separation was carried out on a chromatographic column filled with Hypersil SiO2, 5 μm. The cypermethrin content was quantified by the internal standard method. 1240
4.3.2 Instruments and Equipment
HG 3627--1999
Liquid chromatograph: with ultraviolet variable wavelength detector. Chromatographic data processor.
Chromatographic column: 4.6 mm (id) × 200 mm stainless steel column, filled with Hypersil SiO, 5μm. Filter: The pore size of the filter membrane is about 0.45μm. bzxZ.net
Micro-injector: 50μL.
4.3.3 Reagents and solutions
N-hexane: Chromatographic grade.
Ethyl acetate: Chromatographic grade.
Mobile phase: sub (n-hexane: ethyl acetate) = 99:1. Use a pipette to transfer 10mL of ethyl acetate into 990mL of n-hexane, shake well, filter through a 0.45um filter membrane, and ultrasonicate for 15min. Methyl benzoate: It should not contain impurities that interfere with the analysis. Internal standard solution: Weigh 3.8g of methyl benzoate, put it in a 1000mL volumetric flask, dissolve it with mobile phase and make up to volume, shake it. Cypermethrin standard: known content, greater than or equal to 98.0%. 4.3.4 Liquid chromatography operating conditions
Column temperature: room temperature (temperature difference should not exceed 2℃). Mobile phase flow rate: 1.0mL/min.
Detection wavelength: 278nm.
Injection volume: 10μL.
Retention time: methyl benzoate 4.5min; low efficiency cis [(R)-α, (1R)-cis + (S)-α, (1S)-cis] 7.8min; high efficiency cis [(S)-α, (1R)-cis + (R)-α, (1S)-cis] 9.2min, low efficiency trans [(R)-α, (1R)-trans + (S)-α, (1S)-trans] 710.3min; high efficiency trans [(S)-α, (1R)-trans + (R)-α, (1S)-trans] 11.9min (see Figure 2). 1 Internal standard (methyl benzoate)
a—low efficiency cis [(R)-α, (1R)-cis + (S)-α, (1S)~cis], b—high efficiency Gu [(S)-α, (1R)-cis + (R)-α, (1S)-]; c—low efficiency trans [(R)-α, (1R)-trans + (S)-α, (1S)-trans]; d—high efficiency trans [(S)-α, (1R)-trans + (R)-α, (1S)-trans] Figure 2 Liquid phase chromatogram of cypermethrin original drug
The above liquid chromatography 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.
4.3.5 Determination steps
a) Preparation of standard solution
Weigh 0.05 g (accurate to 0.0002 g) of cypermethrin standard into a 15 mL stoppered glass bottle, and add 10 mL of internal standard solution using a pipette.Dissolve and shake well.
b) Preparation of sample solution
HG 3627-1999
Weigh 0.05g of sample containing cypermethrin (accurate to 0.0002g), put it into a 15mL stoppered glass bottle, add 10mL of internal standard solution using the same pipette as in a), dissolve and shake well. Then filter with a 0.45μm filter membrane. c) Determination
Under the above operating conditions, after the instrument is stable, continuously inject several injections of standard solution until the relative change of the ratio of the total peak area of chlorpermethrin to the peak area of methyl benzoate between two adjacent injections is less than 1.0%, and then analyze and determine in the order of standard solution, sample solution, sample solution, and standard solution.
4.3.6 Calculation
The total content of cypermethrin expressed as mass percentage (X1) is calculated according to formula (1): Xi = remiP
Wherein: 1—the average value of the ratio of the total peak area of cypermethrin in the standard solution to the peak area of the internal standard; F2—the average value of the ratio of the total peak area of cypermethrin in the sample solution to the peak area of the internal standard; m1—the mass of the standard, g,
—the mass of the sample, g;
P—the total content of cypermethrin in the standard,%. 4.3.7 Allowable difference
Take the arithmetic mean as the determination result. The difference between two parallel determination results shall not exceed 1.5%. 4.4 Determination of moisture
4.4.1 Determination method
It shall be carried out according to the Karl Fischer method in GB/T1600. It is allowed to use a moisture analyzer with equivalent accuracy for determination. 4.4.2 Allowable difference
Take the arithmetic mean as the determination result. The difference between two parallel determination results should not exceed 30%. 4.5 Determination of acidity
4.5.1 Reagents and solutions
Sodium hydroxide standard titration solution: c(NaOH)=0.02mol/L, prepared according to the method specified in GB/T601. Mixed indicator solution: 2mL of 1g/L methyl red ethanol solution and 10mL of 1g/L bromocresol green ethanol solution are mixed evenly. 95% ethanol.
4.5.2 Determination steps
Weigh 2g of the sample (accurate to 0.0002g), place it in a 250mL conical flask, add 50mL of 95% ethanol, shake to dissolve the sample evenly, add 4~~6 drops of mixed indicator solution, and titrate with sodium hydroxide standard titration solution until the color changes from light red to dark green as the end point. At the same time, make a blank determination.
4.5.3 Calculation
The acidity (X) of the sample expressed as mass percentage (in terms of H2SO4) is calculated according to formula (2): X = c(Vi-V) × 0.049 × 100m
Wherein: c——actual concentration of sodium hydroxide standard titration solution, mol/L; V
—volume of sodium hydroxide standard titration solution consumed in titrating the sample solution, mL; V
volume of sodium hydroxide standard titration solution consumed in titrating the blank solution, mL, mass of the sample, g;
(2)
mass of sulfuric acid in grams equivalent to 1.00 mL sodium hydroxide standard titration solution [c(NaOH)=1.000 mol/L].
4.5.4 Allowable difference
HG 3627—1999
Take the arithmetic mean as the determination result. The relative difference between the results of two parallel determinations shall not exceed 30%. 4.6 Determination of the ratio of high-efficiency and low-efficiency isomers
4.6.1 Determination steps
The determination of the ratio R of high-efficiency and low-efficiency isomers can be carried out simultaneously with 4.3. The ratio R of high-efficiency and low-efficiency isomers can be calculated according to formula (3): R=
Wherein: Aa—
-peak area of peak α;
peak area of peak 6;
peak area of peak c;
peak area of peak α.
4.6.2 Allowable difference
A, + Ad
Take the arithmetic mean as the determination result. The difference between the results of two parallel determinations shall not exceed 0.05. 4.7 Inspection and acceptance of products
Inspection and acceptance of products shall comply with the provisions of GB/T1604. The rounding value comparison method is used for the processing of limit values. 5 Marking, labeling, packaging, storage and transportation
(3)
5.1 The marking, labeling and packaging of cypermethrin technical shall comply with the relevant provisions of GB3796 and GB4838. Flucythrin technical in circulation as a commodity shall have a production license number and trademark. 5.2 Cypermethrin technical shall be packaged in clean, dry iron drums lined with polyvinyl chloride (PVC), with a net content of 200 kg per drum. 5.3 Other forms of packaging may be used according to user requirements or order agreements, but they must comply with the relevant provisions of GB4838. 5.4 Cypermethrin technical packaging shall be stored in a ventilated and dry warehouse. 5.5 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. 5.6 Safety: This product is a moderately toxic insecticide of the pyrethroid class and can penetrate through the skin. When using this product, you should wear protective gloves, masks, and clean protective clothing. After use, wash with soap and water immediately. If poisoning is found, go to the hospital for examination and treatment in time. Warranty period: Under the specified storage and transportation conditions, the warranty period of cypermethrin technical is 2 years from the date of production. 5.7
A1 Method Summary
HG 3627--1999
Appendix A
(Appendix of the standard)
Determination of cypermethrin content
The sample is dissolved in n-hexane, and n-hexane-anhydrous ether is used as the mobile phase. A stainless steel column with SiO2 as the filler and an ultraviolet detector (230 nm) are used to separate and determine the cypermethrin in the sample by normal phase high performance liquid chromatography. A2 Reagents and solutions
N-hexane: chromatographic grade.
Anhydrous ether: chromatographic grade.
Mobile phase: (n-hexane: anhydrous ether) = 98:2, filtered through a 0.45μm filter membrane, and ultrasonicated in an ultrasonic bath for 10 minutes. Cypermethrin standard: known content, greater than or equal to 98.0%. A3 Instruments and equipment
High performance liquid chromatograph: with variable wavelength UV detector. Chromatographic column: 150mmX3.9mm (id) stainless steel column, filled with Nova-PakSiO filler, particle size 5μm. Chromatographic data processor.
Filter: The pore size of the filter membrane is about 0.5μm. Micro-injector: greater than or equal to 50μL.
A4 High performance liquid chromatography operating conditions
Flow rate: 1.0mL/min.
Column temperature: room temperature (temperature difference is not greater than 2℃). Detection wavelength: 230nm.
Injection volume: 10μL.
Retention time:
Low efficiency cis [(R)-α, (1R)-cis + (S)-α, (1S)-cis] 8.4 min; high efficiency cis [(S)-α, (1R)-cis + (R)-α, (1S)-cis] 9.6 min; low efficiency trans [(R)-α, (1R)-trans + (S)-α, (1S)-trans] 10.8 min; high efficiency trans [(S)-α, (1R)-trans + (R)-α, (1S)-trans] 12.3 min (see Figure A1). 1244
HG 3627—1999
a-Low efficiency cis [(R)-α, (1R)-cis + (S)-α, (1S)-cis]; b-High efficiency cis [(S)-α, (1R)-cis + (R)-α, (1S)-cis], c-Low efficiency trans [(R)-α, (1R)-trans + (S)-α, (1S)-trans]; d-High efficiency trans [(S)-α, (1R)-trans + (R)-α, (1S)-trans] Figure A1 Liquid chromatogram of cypermethrin technical drug
The above operating parameters are typical. According to the characteristics of different instruments, the given operating parameters can be appropriately adjusted to obtain the best effect (see Figure A1).
A5 Determination steps
a) Preparation of standard solution
Weigh 0.025g (accurate to 0.0002g) of cypermethrin standard, place it in a 25mL volumetric flask, dissolve it with n-hexane and dilute it to the scale, and shake it well.
b) Preparation of sample solution
Weigh 0.025g (accurate to 0.0002g) of cypermethrin sample, place it in a 25mL volumetric flask, dissolve it with n-hexane and dilute it to the scale, and shake it well.
c) Determination
Under the above operating conditions, after the instrument baseline is stable, continuously inject several needles of standard solution until the change in the cypermethrin peak area between two adjacent needles is less than 1.5%, the determination is carried out in the order of standard solution, sample solution, sample solution, and standard solution. A6 Calculation
Average the peak areas of cypermethrin in the two sample solutions and the peak areas of cypermethrin in the two standard solutions before and after the sample.
The cypermethrin content (X1) expressed as mass percentage is calculated according to formula (A1): Xi
-the average value of the peak area of cypermethrin in the standard solution, where: A,—
A7 Allowable difference
The average value of the peak area of cypermethrin in the sample solution, the mass name of the cypermethrin standard:
The mass of the sample, g,
The mass percentage of cypermethrin in the standard sample, %. Take the arithmetic mean as the determination result. The difference between the results of two parallel determinations should not be greater than 1.0%. .(A1)
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