Some standard content:
HG3620—1999
This standard is compiled based on the actual production situation of fenbucarb emulsifiable concentrate by various manufacturers in my country. The test method for the active ingredient content in this standard is the reverse phase high performance liquid chromatography method, which is equivalent to the normal phase high performance liquid chromatography method adopted by the Council for International Pesticide Analysis Cooperation (CIPAC).
Appendix A of this standard is the appendix of the standard.
This standard was proposed by the Technical Supervision Department of the former Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. The main drafting unit of this standard: Hunan Chemical Industry Research Institute. The participating drafting units of this standard: Hunan Haili Chemical Co., Ltd. Test Plant, Hunan Linxiang Amino Chemicals Factory, Wuxi Huishan Pesticide Factory.
The main drafters of this standard: Fu Deling, Huang Lu, Yu Yanfeng, Liu Zhijuan, Zheng Jingyu. 1188
Chemical Industry Standard of the People's Republic of China
Fenobucarb emuisifiable concentrate
Fenobucarb emuisifiable concentratesOther names, structures and basic physicochemical parameters of Fenobucarb are as follows:ISO common name: Fenobucarb
CIPAC digital code: 390
Chemical name: 2-sec-butylphenyl methylcarbamate 2-(1-methylpropylphenyl) methylcarbamateStructural formula:
O--CO--NHCH:
CH—C,H,
Empirical formula: C12HmNOz
Relative molecular mass: 207.3 (according to the international relative atomic mass in 1993)Biological activity: Insecticidal
Melting point: 31~32℃
Vapor pressure (20℃).1.6mPa
HG 3620—1999
Solubility: 610 mg/L (30°C) in water; greater than 1 kg/kg at room temperature for acetone, benzene, toluene and xylene. Stability: unstable to alkali and concentrated acid, easily decomposed by heat. 1 Scope
This standard specifies the requirements, test methods, marking, labeling, packaging, storage and transportation of Fenbucarb emulsifiable concentrate. This standard applies to Fenbucarb emulsifiable concentrate prepared by dissolving Fenbucarb technical and emulsifier that meet the standards in a suitable solvent. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard by reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, 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/T603—1988 Preparation of preparations and products used in test methods for chemical reagents GB/T1250—1989 Methods for expressing and determining limit values GB/T1600—1979 (1989) Method for determining moisture content in pesticides GB/T1603—1979 (1989) Method for determining stability of pesticide emulsions GB/T1604-—1995
Rules for acceptance of commercial pesticides
GB/T 1605—1989
Methods for sampling commercial pesticides
GB3796—1983 General rules for pesticide packaging
GB 4838—1984
ECP pesticide packaging
Approved by the State Administration of Petroleum and Chemical Industry on 1999-06-16 and implemented on 2000-06-01
3 Requirements
3620—1999
3.1 Appearance: Stable light yellow or brownish red homogeneous liquid, without visible suspended matter and precipitation. 3.2 Fenbuterol EC shall meet the requirements of Table 1. Table 1 Control item indicators of Fenbuterol emulsifiable concentrate
80% emulsifiable concentrate
Fenbuterol content, %
O-sec-butyl content, %
Water, %
Acidity or alkalinity
Acidity (in H2SO,), %
Alkalinity (in NaOH), %
Emulsion stability (diluted 200 times)
Low temperature stability
Hot storage stability
Note: In normal production, low temperature stability and hot storage stability are measured once every quarter. 4 Test method
4.1 Sampling
50% emulsifiable concentrate
20% emulsifiable concentrate
The sampling was carried out in accordance with the "sampling method for emulsions and liquids" in GB/T1605-1989. The sampling packages were determined by the random number table method, and the final sampling volume should be no less than 250 mL.
4.2 Identification test
This identification test can be carried out simultaneously with the determination of the content of fenbucarb. Under the same chromatographic operating conditions, the relative difference between the retention time of a chromatographic peak of the sample solution and the retention time of the chromatographic peak of fenbucarb in the standard solution should be within 1.5%. 4.3 Determination of fenbucarb content
4.3.1 Summary of the method
The sample was dissolved in methanol, methanol-10 water was used as the mobile phase, a stainless steel column with C1s as the filler and an ultraviolet detector were used to quantify the sample. The fenbucarb in the solution was separated and determined by liquid chromatography, and the external standard method was used for quantification. 4.3.2 Reagents and solutions
Methanol: high-grade purity.
Water: distilled twice.
Fenbucarb standard sample: greater than or equal to 99.5%. bzxz.net
4.3.3 Instruments and equipment
High performance liquid chromatograph: with adjustable wavelength ultraviolet detector. Chromatographic data processor.
Chromatographic column: 150mm×4.6mm(id) stainless steel column, filled with C (5μm) filler. Injector: 50L.
Volume flask: 25mL, calibrated and qualified.
Injection quantitative loop: 20μL.
4.3.4 Chromatographic operating conditions
Mobile phase: methanol + water = 67+33 (volume ratio). 1190
Flow rate: 1. 2 mL/min.
Detection wavelength: 270nm.
Temperature: room temperature.
Quantitative method: external standard method.
HG 3620—1999
Retention time (min): sec-butylcarb 5.24; o-sec-butylphenol 7.36. The above operating parameters are typical (see Figure 1). The given operating parameters can be appropriately adjusted according to the characteristics of the instrument in order to obtain the best effect. 1 sec-butylcarb; 2—Solvent; 3—O-butylphenol
Figure 1 Liquid chromatography separation diagram of sec-butylcarb emulsion
4.3.5 Determination steps
4.3.5.1 Preparation of standard solution
Weigh 0.1g of sec-butylcarb standard (accurate to 0.000 2g), place it in a 25mL volumetric flask, add 15mL of methanol, and vibrate under ultrasonic for 1 min, then dilute with methanol, shake well and filter (0.45 μm) for later use. 4.3.5.2 Preparation of sample solution
Weigh the emulsifiable concentrate sample containing 0.1 g of fenbucarb (accurate to 0.000 2 g), place it in a 25 mL volumetric flask, dilute with methanol, shake well and filter for later use.
4.3.5.3 Determination
Under the above operating conditions, after the instrument is stable, continuously inject several needles of standard solution, calculate the change of the response value of two adjacent needles, and when the change of the response value of two adjacent needles is less than 1.5%, determine in the order of standard solution, sample solution, sample solution, and standard solution. 4.3.6 Calculation
Average the peak areas of fenbucarb in the two needles of sample solution and the two needles of standard solution before and after the sample solution. The content of famoxadicarb expressed as mass percentage (X,) is calculated according to formula (1): r2m,P
wherein: ri—
the average value of the area of famoxadicarb in the standard solution, r2—the average value of the area of the famoxadicarb peak in the sample solution, mass of the famoxadicarb standard sample, name,
the mass of the sample, g,
—the mass percentage of famoxadicarb in the standard sample. 4.3.7 Allowable difference
The difference between the results of two parallel determinations shall not be greater than 1.5%, 1.0% and 0.5% for 80%, 50% and 20% emulsifiable concentrates, respectively. 4.4 Determination of o-sec-butylphenol (free phenol) content (1)
4.4.1 Summary of the method
HG 3620—1999
The sample was dissolved in methanol, methanol-10 water was used as the mobile phase, a stainless steel column filled with C18 (5 μum) and a UV detector were used, and the o-sec-butylphenol in the sample was separated and determined by high performance liquid chromatography using the external standard method. 4.4.2 Reagents and solutions
Methanol: high purity.
Water: distilled twice.
Standard sample: o-sec-butylphenol, known content greater than or equal to 99.0%. 4.4.3 Instruments and equipment
Volume flask: 25mL, 100mL, calibrated and qualified. Pipette: 1mL, calibrated and qualified.
Others are the same as 4.3.3.
4.4.4 HPLC operating conditions
Same as 4.3.4.
4.4.5 Determination steps
4.4.5.1 Preparation of standard solution
Weigh 0.05g (accurate to 0.0002g) of o-sec-butylphenol standard, place it in a 100mL volumetric flask, dissolve it with methanol and make up to volume, shake it well, take 1.00mL and place it in a 25mL volumetric flask, make up to volume with mobile phase, shake it well and filter it (0.45μm) for later use. Note: If the standard solution changes color, it cannot be used and needs to be re-prepared. 4.4.5.2 Preparation of sample solution
Same as 4.3.5.2.
4.4.5.3 Determination
Same as 4.3.5.3.
4.4.6 Calculation
Average the peak areas of o-sec-butylphenol in the two sample solutions and the two standard solutions before and after the sample solution. The o-sec-butylphenol content (X,) expressed as mass percentage is calculated according to formula (2): X
wherein: r-
0. 01 rzm,P
-average value of the peak area of o-sec-butylphenol in the standard solution; average value of the peak area of o-sec-butylphenol in the sample solution; -mass of o-sec-butylphenol standard sample, g;
mz--mass of the sample, g;
P-mass percentage of o-sec-butylphenol standard sample; 0.01-dilution conversion factor.
4.4.7 Allowable difference
The relative deviation of the two determination results shall not exceed 20%. 4.5 Determination of moisture content
Carry out according to the Karl Fischer method in GB/T1600-1989 Method for determination of moisture content in pesticides. 4.6 Determination of acidity (or alkalinity)
4.6.1 Reagents and solutions
Acetone: analytical grade.
Sodium hydroxide standard titration solution c(NaOH)=0.02mol/L, prepared and calibrated according to the method specified in GB/T601. Hydrochloric acid standard titration solution: c(HC1)=0.02mol/L, prepared and calibrated according to the method specified in GB/T601. Methyl red ethanol solution indicator solution: 1g/L, prepared according to the method specified in GB/T603. 1192
(2)
4.6.2 Instruments and equipment
Erlenmeyer flask: 250mL.
Burette: 5mL.
Graduating cylinder: 50mL.
4.6.3 Determination steps
HG 3620—1999
Weigh 10g of the sample (accurate to 0.01g), place it in a 250mL conical flask, add 30mL of acetone, shake well, add 30mL of water and shake, add 3-4 drops of indicator solution, shake, and titrate with sodium hydroxide standard titration solution (or hydrochloric acid standard titration solution) until the color changes from red to yellow (or from yellow to red).
At the same time, make a blank determination.
4.6.4 Calculation
The acidity of the sample expressed in mass percentage (X,) (in terms of H,SO4) is calculated according to formula (3): X, - cV-Ve) × 0. 049 × 100
The alkalinity of the sample expressed in mass percentage (X.) (in terms of NaOH) is calculated according to formula (4): X - 2V-V × 0. 040 × 100
Where: c
actual concentration of sodium hydroxide (or hydrochloric acid) standard titration solution, mol/L; Vi—volume of sodium hydroxide (or hydrochloric acid) standard solution consumed in titrating the sample solution, mL; V. —Blank solution is titrated, the volume of sodium hydroxide (or hydrochloric acid) standard solution consumed, mL mass of sample, g;
(3)
(4)
The mass of sulfuric acid in grams equivalent to 1.00 mL sodium hydroxide standard titration solution [c(NaOH)=1.000 mol/LJ,
0.040——The mass of sodium hydroxide in grams equivalent to 1.00 mL hydrochloric acid standard titration solution Lc(HC1)=1.000 mol/L]. 4.6.5 Allowable difference
The relative deviation of two parallel determination results shall not exceed 20%. 4.7 Emulsion stability test
The emulsifiable concentrate is diluted 200 times with standard hard water and tested according to GB/T1603. It is qualified if there is no floating oil on the surface and no precipitation on the bottom. 4.8 Low temperature stability test
4.8.1 Method summary
The sample is kept at 0℃ for 1h, and the presence of solid and oily substances is recorded. 4.8.2 Instruments and equipment
Refrigerator: maintain (0±1)℃.
Centrifuge tube: 100mL, with scale accurate to 0.05mL at the bottom of the tube. 4.8.3 Determination steps
Take 100mL±1.0mL of sample and add it to the centrifuge tube, cool it to (0±1)℃ in the refrigeration tube, and keep the centrifuge tube and its contents at (0±1)℃ for 1h. Stir once every 15min for 15s each time, and check and record whether there is solid or oily substances precipitated. No floating oil on the top and no precipitation on the bottom are qualified.
4.9 Hot storage stability test
4.9.1 Instruments and equipment
Thermostatic box: maintain (54±2)℃.
An: 50mL.
Medical syringe: 50mL.
4.9.2 Determination steps
HG3620—1999
Use a syringe to inject about 30mL of the emulsifiable concentrate sample into clean an, place the an in an ice-salt bath to cool, and quickly seal it with a high-temperature flame. Seal at least 3 bottles and weigh them separately. Place the sealed ones in a metal container, and then put the metal container in a (54±2)℃ constant temperature box for 14 days. Take it out and cool it to room temperature, wipe the outside of the an and weigh it separately. For samples that have not changed in mass, test the specified items within 24 hours, and the decomposition rate of the active ingredients should not be greater than 5%. 4.10 Inspection and acceptance of products
It should comply with the relevant provisions of GB/T1604. The rounded value comparison method is used for the processing of limit values. 5.1 The signs, labels, packaging, storage and transportation of Zhongdingwei EC shall comply with the relevant provisions of GB3796 and GB4838, and shall have the production license number and trademark.
5.280% and 50% Zhongdingwei EC shall be packaged in 200L galvanized iron barrels, with a net content of (200±1)kg per barrel, and the barrel cover must be sealed without leakage. 20% Zhongdingwei EC shall be packaged in 500mL glass bottles or plastic bottles with inner and outer covers, and the outer packaging shall be in calcium plastic boxes, with 20 bottles per box. 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 Packages shall be stored in ventilated and dry warehouses. 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 low-toxic insecticide and general protective measures can be taken when used. In case of poisoning, atropine sulfate can be used for detoxification and treatment can be carried out according to the doctor's advice when necessary.
5.7 Warranty period: The product should meet the indicators in Table 1 in 3.2 when it leaves the factory. Under the specified storage and transportation conditions, the warranty period of F-butylcarb EC is two years from the date of production. During the warranty period, the content of 80%, 50% and 20% F-butylcarb EC shall not be less than 77%, 48% and 19% respectively; the content of o-sec-butylphenol shall not be more than 0.8%, 0.6% and 0.6% respectively. 1194
HG 3620—1999
Appendix A
(Appendix to the standard)
Determination of F-butylcarb content by gas chromatography and determination of sec-butylphenol (free phenol) content by colorimetry A1 F-butylcarb content by gas chromatography This method can be used for production control analysis.
A1.1 Method Summary
The sample was dissolved in trifluoromethane, diethyl bis(2-ethylhexanoate) was used as the internal standard, and a 1m glass column filled with 5% OV-101/ChromsorbG-AW.DMCS (200~～250μm) and a hydrogen flame detector were used to separate and determine the fenbucarb by gas chromatography. A1.2 Instruments and Equipment
Gas chromatograph: with hydrogen flame ionization detector and glass column head injector. Chromatographic data processor.
Chromatographic column: 1000mmX3.4mm(id) glass column. Column filling: 5% OV-101/ChromsorbG-AW.DMCS (200~250 μm). Injector: 1μL.
Volume flask: 10mL.
Pipette: 1 mL.
A1.3 Reagents and solutions
Chloroform: analytical grade.
Standard sample of fenbucarb: greater than or equal to 99.5%.
Internal standard: diethyl azelaate, which should not contain impurities that interfere with analysis. Carrier: Chromsorb G-AW.DMCS (200~250μm). Internal standard solution: 100g/L,The trifluoromethane solution of diethyl oxadiazine should be stored in a refrigerator and can be used only after returning to room temperature. Stationary liquid: OV-101.
A1.4 Preparation of chromatographic columns
A1.4.1 Coating of stationary liquid
Weigh about 0.5g of OV-101 in a 200mL beaker, add a little trifluoromethane, stir with a glass rod to completely dissolve OV-101, then add an appropriate amount of trifluoromethane (the solvent should just cover the carrier), and stir. Pour the weighed 10g of the carrier into the above beaker at a time, dry the beaker plate under an infrared lamp, and gently shake the beaker from time to time to keep it in a uniform state. When the solvent evaporates, place the beaker in a 100℃ oven and dry for 1h.
A1.4.2 Filling of chromatographic column
Connect the inlet end of the clean and dry chromatographic column with a funnel, wrap the outlet end with a clean gauze, and connect it to the vacuum pump with a clean rubber tube. Turn on the vacuum pump and pour the filler in from the funnel in batches. At the same time, tap the column wall continuously to make the filler fill the chromatographic column tightly and evenly. Then plug a small ball of silanized glass wool at both ends of the column and press it properly to prevent the filler from moving. A1.4.3 Aging of chromatographic column
Connect the inlet end of the chromatographic column to the vaporization chamber, and do not connect the outlet end to the detector for the time being. Raise the temperature to 250℃ in stages at a carrier gas flow rate of about 20mL/min, and age at this temperature for 24h. After cooling down, connect the outlet end of the column to the detector. A1.5 Gas chromatography operating conditions
Temperature (℃): vaporization chamber 180;
column temperature 155;
detection chamber 180.
Gas flow rate (mL/min): carrier gas (Nz) 60; hydrogen 50;
air 500.
Retention time (min): famoxadicarb 5.45; internal standard 7.86.
Injection volume: 0.3μL.
Determination method: internal standard method.
HG 3620—1999
The above operating parameters are typical. According to the characteristics of the instrument, the given parameters can be appropriately adjusted to obtain the best effect (see Figure A1). 2
1-Solvent; 2-Impurity; 3-Fenbucarb; 4-Internal Standard Figure A1 Gas Chromatographic Separation Diagram of Fenbucarb
A1.6 Determination Steps
A1.6.1 Preparation of Standard Solution
Weigh 0.1g of Fenbucarb Standard Sample (accurate to 0.0002g), place in a 10mL volumetric flask, add 1.0mL of internal standard solution, then add 4mL of trifluoromethane, shake well and set aside.
A1.6.2 Preparation of Sample Solution
Weigh about 0.1g of pure Fenbucarb Sample (accurate to 0.0002g), place in a 10mL volumetric flask, add 1.0mL of internal standard solution, then add 4mL of trifluoromethane, shake well and set aside.
A1.6.3 Determination
Under the above operating conditions, after the instrument is stable, use a microsyringe to inject the standard solution for several needles. When the relative peak height ratio of two adjacent needles changes less than 1.5%, the determination is carried out in the order of standard solution, sample solution, sample solution, and standard solution. A1.7 Calculation
The measured peak height ratios of the two needles of sample solution and the two needles of standard solution before and after the sample solution are averaged respectively. The content of the second but carbamide expressed as a mass percentage (X,) is calculated according to formula (A1):tamP
In the formula: r-
the average value of the peak height ratio of the second but carbamide to the internal standard in the standard solution; the average value of the peak height ratio of the second but carbamide to the internal standard in the sample solution; the mass of the second but carbamide standard sample, g;
m2-the mass of the second but carbamide sample, g;
P——the mass percentage of the second but carbamide in the standard sample. A2 Colorimetric determination method of o-sec-butylphenol (free phenol) This method can be used for production control analysis.
A2.1 Method summary
(A1)
O-sec-butylphenol reacts with sodium nitrite under acidic conditions to generate nitroso-o-sec-butylphenol. After adding methylamine solution, a yellow wake-type compound is formed. The spectrophotometric determination is carried out at a wavelength of 410nm. A2.2 Reagents and solutions
Methanol: analytical grade.
Sodium carbonate: analytical grade.
Sodium nitrite: analytical grade.
30% methylamine solution: analytical grade.
HG 3620—1999
O-sec-butylphenol standard: content greater than or equal to 99%, hydrochloric acid solution: c(HCI)=0.1 mol/L. Prepared according to the method specified in GB/T 601. Sodium nitrite solution: c(NaNO2)=1mol/L. Weigh 1.7g sodium nitrite, place in a 25mL volumetric flask, dissolve and dilute with water, shake well for use (prepare on the same day only). Standard solution of o-sec-butylphenol: weigh 0.01g o-sec-butylphenol (accurate to 0.0002g), place in a 100mL volumetric flask, dissolve and dilute with acetone, shake well for use.
A2.3 Instruments and equipment
Spectrophotometer.
Water bath.
Volume flask: 25mL, 100mL.
Colorimetric tube with stopper: 25mL.
Pipette: 0.5mL; 2mL.
A2.4 Determination steps
Weigh a sample of sec-butylphenol emulsifiable concentrate containing 0.0025g of o-sec-butylphenol (accurate to 0.0002g), place it in a 25mL volumetric flask, dissolve it with acetone and make up to volume. Pipette 0.2mL of the test solution into a 25mL colorimetric tube, add 1.5mL of hydrochloric acid solution, add 2mL of sodium nitrite solution along the wall, shake for 1min, place it in a 30℃ water bath for 20min, then add 0.25mL of methylamine solution, dilute it with water to 10mL, and measure the absorbance at a wavelength of 410nm with water as the reference solution. Perform a blank test at the same time.
Take another 0.2mL of o-sec-butylphenol standard solution and measure the absorbance according to the determination procedure of the sample solution. A2.5 Calculation
The content of o-sec-butylphenol expressed as mass percentage (X.) is calculated according to formula (A2): 0. 25 E2mP
-the absorbance of the standard solution minus the absorbance after blank; where: E,—
the absorbance of the sample solution minus the absorbance after blank; the mass of the standard, g;
the mass of the sample·g
the mass percentage of the o-sec-butylphenol standard; conversion factor.
A2.6 Allowable difference
The relative deviation of the results of two parallel determinations should not be greater than 20%. (A2)0002g), place it in a 10mL volumetric flask, add 1.0mL of internal standard solution, then add 4mL of trifluoromethane, shake well and set aside.
A1.6.2 Preparation of sample solution
Weigh a sample containing about 0.1g of pure famoxadicarb (accurate to 0.0002g), place it in a 10mL volumetric flask, add 1.0mL of internal standard solution, then add 4mL of trifluoromethane, shake well and set aside.
A1.6.3 Determination
Under the above operating conditions, after the instrument is stable, use a microsyringe to inject a few needles of standard solution. When the relative peak height ratio of the two adjacent needles changes by less than 1.5%, measure in the order of standard solution, sample solution, sample solution, and standard solution. A1.7 Calculation
Average the ratio of the peak height of famoxadicarb to the internal standard substance in the two needles of sample solution and the two needles of standard solution before and after the sample solution. The content of sec-butylcarb expressed as mass percentage (X,) is calculated according to formula (A1): tamP
wherein: r-
the average value of the peak height ratio of sec-butylcarb to the internal standard in the standard solution; a-the average value of the peak height ratio of sec-butylcarb to the internal standard in the sample solution; the mass of the sec-butylcarb standard sample, g;
m2-the mass of the sec-butylcarb sample, g;
P——the mass percentage of sec-butylcarb in the standard sample. A2 Colorimetric determination method of o-sec-butylphenol (free phenol) This method can be used for production control analysis.
A2.1 Method Summary
(A1)
O-sec-butylphenol reacts with sodium nitrite under acidic conditions to generate nitroso-o-sec-butylphenol, which forms a yellow wake-type structure compound after adding methylamine solution, and is spectrophotometrically determined at a wavelength of 410nm. A2.2 Reagents and solutions
Methanol: analytical grade.
Sodium carbonate: analytical grade.
Sodium nitrite: analytical grade.
30% methylamine solution: analytical grade.
HG 3620—1999
O-sec-butylphenol standard: content greater than or equal to 99%, hydrochloric acid solution: c(HCI)=0.1 mol/L. Prepare according to the method specified in GB/T 601. Sodium nitrite solution: c(NaNO2)=1mol/L. Weigh 1.7g sodium nitrite, place in a 25mL volumetric flask, dissolve and dilute with water, shake well for use (prepared only on the same day). O-sec-butylphenol standard solution: Weigh 0.01g of o-sec-butylphenol (accurate to 0.0002g), place in a 100mL volumetric flask, add acetone to dissolve and dilute, shake well for use.
A2.3 Instruments and equipment
Spectrophotometer.
Water bath.
Volume flask: 25mL, 100mL.
Colorimetric tube with stopper: 25mL.
Pipette: 0.5mL; 2mL.
A2.4 Determination steps
Weigh the 2-butylene glycol emulsifiable concentrate sample containing 0.0025g of o-sec-butylphenol (accurate to 0.0002g), place it in a 25mL volumetric flask, dissolve it with acetone and make up to volume. Pipette 0.2mL of test solution into a 25mL colorimetric tube, add 1.5mL of hydrochloric acid solution, add 2mL of sodium nitrite solution along the wall, shake for 1min, place in a 30℃ water bath for 20min, then add 0.25mL of methylamine solution, dilute to 10mL with water, and measure the absorbance at a wavelength of 410nm with water as the reference solution. Perform a blank test at the same time.
Take another 0.2mL of o-sec-butylphenol standard solution and measure the absorbance according to the measurement procedure of the sample solution. A2.5 Calculation
The content of o-sec-butylphenol expressed as mass percentage (X.) is calculated according to formula (A2): 0. 25 E2mP
-the absorbance of the standard solution minus the absorbance after blank; where: E,—
the absorbance of the sample solution minus the absorbance after blank; the mass of the standard, g;
the mass of the sample·g
the mass percentage of the o-sec-butylphenol standard; conversion factor.
A2.6 Allowable difference
The relative deviation of the results of two parallel determinations should not be greater than 20%. (A2)0002g), place it in a 10mL volumetric flask, add 1.0mL of internal standard solution, then add 4mL of trifluoromethane, shake well and set aside.
A1.6.2 Preparation of sample solution
Weigh a sample containing about 0.1g of pure famoxadicarb (accurate to 0.0002g), place it in a 10mL volumetric flask, add 1.0mL of internal standard solution, then add 4mL of trifluoromethane, shake well and set aside.
A1.6.3 Determination
Under the above operating conditions, after the instrument is stable, use a microsyringe to first inject a few needles of standard solution. When the relative peak height ratio of the two adjacent needles changes by less than 1.5%, perform the determination in the order of standard solution, sample solution, sample solution, and standard solution. A1.7 Calculation
Average the ratio of the peak height of famoxadicarb to the internal standard substance in the two needles of sample solution and the two needles of standard solution before and after the sample solution. The content of sec-butylcarb expressed as mass percentage (X,) is calculated according to formula (A1): tamP
wherein: r-
the average value of the peak height ratio of sec-butylcarb to the internal standard in the standard solution; - the average value of the peak height ratio of sec-butylcarb to the internal standard in the sample solution; the mass of the sec-butylcarb standard sample, g;
m2-the mass of the sec-butylcarb sample, g;
P——the mass percentage of sec-butylcarb in the standard sample. A2 Colorimetric determination method of o-sec-butylphenol (free phenol) This method can be used for production control analysis.
A2.1 Method Summary
(A1)
O-sec-butylphenol reacts with sodium nitrite under acidic conditions to generate nitroso-o-sec-butylphenol, which forms a yellow wake-type structure compound after adding methylamine solution, and is spectrophotometrically determined at a wavelength of 410nm. A2.2 Reagents and solutions
Methanol: analytical grade.
Sodium carbonate: analytical grade.
Sodium nitrite: analytical grade.
30% methylamine solution: analytical grade.
HG 3620—1999
O-sec-butylphenol standard: content greater than or equal to 99%, hydrochloric acid solution: c(HCI)=0.1 mol/L. Prepare according to the method specified in GB/T 601. Sodium nitrite solution: c(NaNO2)=1mol/L. Weigh 1.7g sodium nitrite, place in a 25mL volumetric flask, dissolve and dilute with water, shake well for use (prepared only on the same day). O-sec-butylphenol standard solution: Weigh 0.01g of o-sec-butylphenol (accurate to 0.0002g), place in a 100mL volumetric flask, add acetone to dissolve and dilute, shake well for use.
A2.3 Instruments and equipment
Spectrophotometer.
Water bath.
Volume flask: 25mL, 100mL.
Colorimetric tube with stopper: 25mL.
Pipette: 0.5mL; 2mL.
A2.4 Determination steps
Weigh the 2-butylene glycol emulsifiable concentrate sample containing 0.0025g of o-sec-butylphenol (accurate to 0.0002g), place it in a 25mL volumetric flask, dissolve it with acetone and make up to volume. Pipette 0.2mL of test solution into a 25mL colorimetric tube, add 1.5mL of hydrochloric acid solution, add 2mL of sodium nitrite solution along the wall, shake for 1min, place in a 30℃ water bath for 20min, then add 0.25mL of methylamine solution, dilute to 10mL with water, and measure the absorbance at a wavelength of 410nm with water as the reference solution. Perform a blank test at the same time.
Take another 0.2mL of o-sec-butylphenol standard solution and measure the absorbance according to the measurement procedure of the sample solution. A2.5 Calculation
The content of o-sec-butylphenol expressed as mass percentage (X.) is calculated according to formula (A2): 0. 25 E2mP
-the absorbance of the standard solution minus the absorbance after blank; where: E,—
the absorbance of the sample solution minus the absorbance after blank; the mass of the standard, g;
the mass of the sample·g
the mass percentage of the o-sec-butylphenol standard; conversion factor.
A2.6 Allowable difference
The relative deviation of the results of two parallel determinations should not be greater than 20%. (A2)
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