Some standard content:
Chemical Industry Standard of the People's Republic of China
HG2614-94
15% Paclobutrazol Wettable Powder
Published on April 4, 1994
Ministry of Chemical Industry of the People's Republic of China
Implemented on October 1, 1994
Chemical Industry Standard of the People's Republic of China
15% Paclobutrazol Wettable Powder
Subject Content and Scope of Application
HG2614-94
This standard specifies the technical requirements, test methods, inspection rules, and marking, packaging, transportation and storage of Paclobutrazol Wettable Powder. This standard applies to wettable powders made from Paclobutrazol technical, suitable adjuvants and fillers. 2 Reference standards
GB/T1601
GB/T1604
GB/T1605
Method for determination of pH value of pesticides
Pesticide acceptance rules
Commercial pesticide sampling method
GB3796 General rules for pesticide packaging
GB/T5451
GB/T14825
HG/T2-896
3 Technical requirements
Method for determination of wettability of pesticide wettable powdersMethod for determination of suspension rate of pesticide wettable powdersMethod for determination of fineness of pesticide powders
Appearance: Loose fine powder with uniform composition, no lumps. 3.2
Paclobutrazol wettable powder should meet the following index requirements. Item
Paclobutrazol content, %(m/m)
Suspension rate, %(m/m)
Wetting time, s
pH range
Fineness (through 44um sieve), %(m/m)
Test method
4.1 Determination of paclobutrazol
4.1.1 Identification test
Same as original drug.
4.1.2 Determination of paclobutrazol content
4.1.2.1 High performance liquid chromatography internal standard method (arbitration method) 4.1.2.1.1 Method summary
15.0±:
The sample is dissolved in anhydrous ethanol, diethyl fumarate (diethyl maleate) is used as the internal standard, and a mixture of methanol, acetonitrile and water is used as the mobile phase. Use a Nova-pakC1 column and a variable wavelength ultraviolet detector to separate and determine paclobutrazol by high performance liquid chromatography. 4.1.2.1.2 Reagents and solutions
Approved by the Ministry of Chemical Industry of the People's Republic of China on April 4, 1994 and implemented on October 1, 1994
HG2614-94
Paclobutrazol standard sample: known content, ≥99.0% (m/m); internal standard: diethyl fumarate, shall not contain impurities that interfere with analysis; methanol (GB/T683): analytical grade, redistilled; acetonitrile (GB/T3329): analytical grade, redistilled or HPLC grade; anhydrous ethanol (GB/T678): analytical grade;
Water: double distilled water;
Internal standard solution: weigh 0.200g (accurate to 0.0002g) of diethyl fumarate in a 500mL volumetric flask, dilute to the mark with anhydrous ethanol, and shake well.
4.1.2.1.3 Instruments
High performance liquid chromatograph: with variable wavelength UV detector; Chromatographic column: stainless steel column, filled with Nova-pak C1a 4μm, 150×4.6mm (ID); Data processor;
Ultrasonic degassing device;
Micro syringe: 25uL.
4.1.2.1.4 Chromatographic conditions
Mobile phase: methanol + acetonitrile + water = 46+18+36 (V/V); Flow rate: 1.0mL/min;
Column temperature: room temperature;
Measurement wavelength 225nm;
Injection volume: 20uL;
Retention time: internal standard, about 3.4min; paclobutrazol I, about 4.2min;
paclobutrazol, about 5min.
1H-Chlorazine, about 5.8min.
The above operating conditions are typical operating parameters. According to different instruments and chromatographic columns, the given parameters can be appropriately adjusted to obtain the best separation effect.
4.1.2.1.5 Operation steps
a. Preparation of standard solution
Weigh about 0.100g (accurate to 0.0002g) of paclobutrazol standard into a 100mL volumetric flask, dissolve it with anhydrous ethanol, dilute to the scale, and shake well. Then use a pipette to transfer 5mL of standard solution and 5mL of internal standard solution into the same 25mL volumetric flask, dilute to the scale with anhydrous ethanol, and shake well.
b. Preparation of sample solution
Weigh a sample containing about 0.100g (accurate to 0.0002g) of paclobutrazol into a 100mL volumetric flask, dissolve it with anhydrous ethanol, dilute to the mark, and shake well. Use a pipette to accurately transfer 5mL of sample solution and 5mL of internal standard solution into the same 25mL volumetric flask, dilute to the mark with anhydrous ethanol, and shake well.
c. Determination
Under the above operating conditions, after the instrument is stable, continuously inject several needles of standard solution until the relative response value of two adjacent needles changes by less than 1.5%, and then analyze in the following order: a. Standard solution;
b. Sample solution;
c. Sample solution;
Standard solution.
HG2614—94
Figure 1 High performance liquid chromatogram of paclobutrazol wettable powder (internal standard method) 1—auxiliary agent; 2—4H-paclobutrazol; 3—internal standard; 4—paclobutrazol 1; 5—paclobutrazol; 6—1H-chlorazolone
4.1.2.1.6 Calculate the average value of the peak area ratio of paclobutrazol to the internal standard in the two sample solutions and the two standard solutions before and after the sample, respectively. The mass percentage X of paclobutrazol in the sample is calculated according to formula (1): X-2miP
Wherein:
the average value of the peak area ratio of paclobutrazol to the internal standard in the standard solution; the average value of the peak area ratio of paclobutrazol to the internal standard in the sample solution; the mass of the standard,;
m2——the mass of the sample, g;
P——the percentage content of the standard, (m/m). 4.1.2.1.7 Allowable difference
The difference between two parallel determination results shall not exceed 0.5%. 4.1.2.2 High performance liquid chromatography external standard method
4.1.2.2.1 Method summary
(1)
The sample is dissolved in methanol, and a mixture of methanol, acetonitrile and water is used as the mobile phase. The paclobutrazol is separated and determined by high performance liquid chromatography using a Nova-pak C18 column and a variable wavelength ultraviolet detector. 4.1.2.2.2 Reagents
Paclobutrazol standard sample: known content, ≥99.0% (m/m); methanol (GB/T623): analytical grade, redistilled; acetonitrile (GB/T3329): analytical grade;
Water: double distilled water.
4.1.2.2.3 Apparatus
High performance liquid chromatograph: with variable wavelength UV detector; 3
HG2614-94
Chromatographic column: stainless steel column, filled with Nova-pak C184um, 150X4.6mm (ID); data processor;
Ultrasonic degassing device;
Micro syringe: 25uL.
4.1.2.2.4 Chromatographic operating conditions
Mobile phase: methanol + acetonitrile + water = 46 + 18 + 36 (V/V); flow rate: 1.0mL/min;
Column temperature: room temperature;
Measurement wavelength: 230nm;
Injection volume: 20uL.
The above operating conditions are typical operating parameters. According to different instruments and chromatographic columns, the given parameters can be appropriately adjusted to obtain the best separation effect.
4.1.2.2.5 Operation steps
a. Preparation of standard solution
Weigh about 0.100g (accurate to 0.0002g) of paclobutrazol standard sample in a 100mL volumetric flask, dissolve it with methanol, dilute to the scale, and shake well. Use a 5mL pipette to accurately transfer 5mL and dissolve it in another 25mL volumetric flask, dilute it with mobile phase to the scale, and shake well. b. Preparation of sample solution
Weigh about 0.100g (accurate to 0.0002g) of paclobutrazol sample in a 100mL volumetric flask, dissolve it with methanol, dilute to the scale, and shake well. Centrifuge and separate. Use a pipette to accurately transfer 5 mL of the sample solution to another 25 mL volumetric flask, dilute to the mark with the mobile phase, and shake well.
Under the above operating conditions, after the instrument is stable, continuously inject several needles of the standard solution. After the response value of two adjacent needles changes by less than 1.5%, perform the injection analysis in the following order:
Standard solution;
Sample solution;
c.Sample solution;
Standard solution.
4.1.2.2.6 Calculation
HG2614-94
Figure 2 High performance liquid chromatogram of paclobutrazol wettable powder 8
1-Auxiliary agent; 2-4H-paclobutrazol; 3-paclobutrazol 1; 4-paclobutrazol Calculate the average value of the paclobutrazol peak area in the two standard solution and the two sample solutions, and the mass percentage of paclobutrazol in the sample X2, according to formula (2):
Where: A1, A2---are the average values of the paclobutrazol peak area in the two standard solution and the sample solution, respectively; m3.m.-
P--the percentage of the standard, (m/m). 4.1.2.2.7 Allowable difference
The difference between the results of two parallel determinations should not be greater than 0.5%. 4.2 Determination of suspension rate
4.2.1 Method summary: Use standard hard water to prepare the sample to be tested into a suspension of appropriate concentration, the concentration of which should be the highest spraying concentration recommended for the wettable powder. Under the specified conditions, let it stand in the measuring cylinder for 30 minutes, determine the content of the effective ingredient in the bottom tenth of the suspension, and calculate its suspension rate.
4.2.2 Reagents
Magnesium oxide (GB/T9857): Dry at 150℃ for 2h before use; Calcium carbonate (HG/T3-1066): Dry at 400℃ for 2h before use; Hydrochloric acid (GB/T622) solution: 0.1mol/L, 1mol/L; Sodium hydroxide (GB/T629) solution: 0.1mol/L; Ammonia water (GB/T631) 1mol/L;||tt| |Methyl red (HG/T3-958) indicator solution: 1g/L, prepared according to 4.5.6 of GB603; stock solution: A, B preparation method is as follows:
Solution A: (Ca2+) = 0.04mol/L
HG2614-94
Accurately weigh 4.000g of calcium carbonate in an 800mL beaker, add a small amount of water to moisten, slowly add 82mL of 1mol/L hydrochloric acid solution, and stir well. After the calcium carbonate is completely dissolved, add 400mL of water, boil, remove carbon dioxide, cool to room temperature, add 2 drops of methyl red indicator solution, neutralize with ammonia water to orange, quantitatively transfer this solution to a 1000mL volumetric flask, dilute with water to the scale, and mix well. Store in a polyethylene bottle for later use.
Solution B: c(Mg2+)=0.04mol/L
Accurately weigh 1.613g of magnesium oxide and place it in an 800mL beaker, add a small amount of water to moisten it, slowly add 82mL of 1mol/L hydrochloric acid solution, stir thoroughly and slowly heat it. After the magnesium oxide is completely dissolved, add 400mL of water and boil it to remove carbon dioxide. Cool to room temperature, add 2 drops of methyl red indicator solution, neutralize it with ammonia water until it turns orange, transfer this solution to a 1000mL volumetric flask, dilute it with water to the scale, and mix it well. Store it in a polyethylene bottle for later use.
Standard hard water: 342mL in terms of calcium carbonate content. The preparation method is as follows: Transfer 68.5mL of A solution and 17.0mL of B solution to a 1000mL beaker, add 800mL of water, drop 0.1mol/L sodium hydroxide solution or 0.1mol/L hydrochloric acid solution, and adjust the pH to 6.0-7.0 (measured with a pH meter). Transfer the solution to a 1000mL volumetric flask, dilute to the mark with water, and mix well.
4.2.3 Apparatus
Graduating cylinder: 250mL, with ground glass stopper, 0~250mL scale is 20.0~21.5cm apart, the distance between the 250mL scale line and the bottom of the stopper should be 4~6cm,
Glass pipette: about 40cm long, about 5mm in inner diameter, with a hole of about 2~3mm at one end, and the other end of the pipette is connected to the corresponding vacuum source.
Constant temperature water bath, 30±1℃;
Stopwatch. bzxz.net
4.2.4 Determination steps
Weigh 1g of sample (accurate to 0.0002g) and place it in a 200mL beaker containing 50mL of standard hard water (30±1℃). Shake it in a circular motion by hand at 120 times per minute for 2min. Place the suspension in a water bath at the same temperature for 13min. Then wash it all into a 250mL measuring cylinder with 30±1℃ standard hard water and dilute to the scale. Cover the stopper and turn the measuring cylinder upside down 30 times within 1min with the bottom of the measuring cylinder as the axis (turning the measuring cylinder upside down and returning it to its original position is one time, about 2s). Open the stopper and place it vertically in a constant temperature water bath without vibration for 30min. Use a pipette to remove 9/10 (i.e. 225mL) of the suspension in 10-12s. Do not shake or stir up the sediment in the measuring cylinder. Make sure that the top of the pipette is always a few millimeters below the liquid surface. Add 10mL of internal standard solution to the remaining 1/10 suspension and dilute to 100mL with methanol. Shake well and centrifuge. Take the supernatant under given chromatographic conditions for analysis. Calculate the mass of the effective component in the 25mL suspension at the bottom of the measuring cylinder according to 4.1.2.1.6. 4.2.5 Calculate the suspension rate of the sample X: [% (m/m)) Calculate according to formula (3): 10×m1=m2×100=111.1×mm2
Xs-g×-
Where: m1—the mass of the effective component in the sample taken to prepare the suspension, g; m2——the mass of the effective component in the 25mL suspension at the bottom of the measuring cylinder, 8. 4.3 Determination of wetting time
According to the method in GB/T5451.
4.4 Determination of pH
According to the pH meter method in GB/T1601.
4.5 Determination of fineness
According to the wet sieving method in HG/T2-896. 5 Inspection rules
5.1 Sampling method
HG2614-94
According to the "Sampling method for powders and wettable powders" in GB/T1605, sampling is carried out. The sampling packages are determined by random method, and the final sampling volume should be not less than 150g.
5.2 Acceptance rules
Acceptance is carried out in accordance with GB/T1604 standards.
6 Marking, packaging, transportation and purchase and storage
6.1 The packaging and marking of paclobutrazol wettable powder shall comply with the relevant provisions in GB3796 and be marked. 6.2 Paclobutrazol wettable powder is packaged in aluminum-plastic composite bags, with a net weight of 20g, 50g, and 100g per bag; the outer packaging is in calcium plastic boxes or cardboard boxes, with a net weight of 10kg per box.
6.3 Other forms of packaging may be used according to user requirements or agreements reached between the supply and demand parties, but they must meet the packaging quality requirements. 6.4 During storage and transportation, strictly prevent moisture and sunlight, and maintain good ventilation; do not mix with food, seeds, and feed, avoid contact with skin and eyes, and prevent inhalation through the mouth and nose.
6.5 Warranty period: Under the specified storage and transportation conditions, the warranty period of Paclobutrazol wettable powder is at least two years from the date of production. 7
A1 Determination of paclobutrazol content
A1.1 Method summary
HG2614—94
Appendix A
Gas chromatography determination of paclobutrazol
(Supplement)
The sample was extracted with chloroform, dicyclohexyl phthalate was used as the internal standard, and paclobutrazol was separated and determined by gas chromatography using a stainless steel column filled with ChromosorbWAW-DMCs treated with FFAP composite cross-linking and a hydrogen flame ionization detector.
A1.2 Reagents and solutions
Paclobutrazol standard: known content, >99.0% (m/m); internal standard: dicyclohexyl phthalate, must not contain impurities that interfere with the analysis; stationary phase: ChromosorbWAW-DMCS treated with FFAP composite cross-linking bonding, particle size 150~180um; chloroform (GB/T682): analytical grade; hydrogen: deoxygenated;
Internal standard solution: weigh 11g of dicyclohexyl phthalate in a 1000mL volumetric flask, dissolve it in chloroform, dilute to the scale, and shake well.
A1.3 Instruments
Gas chromatograph: with hydrogen flame ionization detector; Chromatographic column: 1000X2mm (ID) stainless steel column, filled with ChromosorbWAW-DMCS stationary phase treated with FFAP composite cross-linking bonding;
Data processor;
Micro-injector: 10uL.
A1.4 Preparation of chromatographic column
a Filling of chromatographic column
Connect a glass funnel to the inlet of the clean and dry chromatographic column, connect the outlet with a joint with a screen, connect it to the vacuum pump with a rubber tube, turn on the vacuum pump, slowly and evenly add the prepared filler from the funnel end, and constantly tap the column wall up and down with a rubber stick to make it tightly and evenly filled (about 1g can be loaded). Remove the chromatographic column, plug a small ball of silanized glass wool at both ends of the column, and bend it into a disc. b. Aging of chromatographic column
Connect the inlet of the chromatographic column to the vaporization chamber, and do not connect the outlet to the detector for the time being. Replace the air in the column with 80mL/min of nitrogen. After 1 hour, increase the temperature to 210℃ at 20mL/min nitrogen and 3℃/min heating rate, and keep it for 24 hours. After cooling, connect the outlet of the column to the detector. A1.5 Gas chromatography operating conditions
Temperature: 200℃ for column chamber, vaporization chamber and detection chamber; Gas flow: carrier gas (high-purity H2), 42mL/min; Tail gas: nitrogen, 28mL/min;
Air, 500mL/min;
Injection volume: about 0.6uL;
Retention time: paclobutrazol, about 10min;
paclobutrazol I, about 12.3min;
dicyclohexyl phthalate, about 14.5min. The above operating conditions can be adjusted appropriately according to different instruments and chromatographic columns to obtain the best effect. A1.6 Determination steps
a. Preparation of standard solution
HG2614-94
Weigh 0.090g (accurate to 0.0002g) of paclobutrazol standard sample into a stoppered glass bottle, accurately add 10mL of internal standard solution with a pipette, and shake well.
Preparation of sample solution
Weigh a sample containing about 0.090g (accurate to 0.0002g) of paclobutrazol into a stoppered glass bottle, accurately add 10mL of internal standard solution with a pipette, shake vigorously for 5min, then pour the solution into a centrifuge test tube, centrifuge for 5min (3500r.pm), take part of the clear liquid into a clean and dry glass bottle for testing.
c. Sample determination
Under the above operating conditions, after the instrument is stable, continuously inject several needles of standard solution. After the relative response value of two adjacent needles changes less than 1.5%, inject and analyze in the following order: a. Standard solution;
b Sample solution;
c. Sample solution;
Standard solution.
Figure 3 Gas chromatogram of paclobutrazol wettable powder 1-solvent, 2-chlorpyrifos; 3-paclobutrazol: 4-paclobutrazol 1; 5-dicyclohexyl phthalate A1.7 Calculation
Calculate the average value of the peak area ratio of paclobutrazol to internal standard in the two sample solutions and the two standard solutions before and after the sample, respectively, and the mass percentage X of paclobutrazol in the sample, according to formula (A1): Tamip
-average value of the peak area ratio of paclobutrazol to internal standard in the standard solution; In the formula: -
average value of the peak area ratio of paclobutrazol to internal standard in the sample solution; P2
-mass of standard sample, 8;
m2-mass of sample, g;
p-percentage content of standard sample, (m/m).
A1.8 Allowable error
The difference between two parallel determination results should not exceed 0.5%. A2 Determination of suspension rate
HG2614—94
A2.1 Method summary: Use standard hard water to prepare the sample to be tested into a suspension of appropriate concentration, the concentration of which should be the highest spraying concentration recommended for the wettable powder. Under the specified conditions, let it stand in the measuring cylinder for 30 minutes, determine the content of the active ingredient in the bottom tenth of the suspension, and calculate its suspension rate.
A2.2 Reagents
Magnesium oxide (GB/T9857): Dry at 150℃ for 2h before use; Calcium carbonate (HG/T3-1066): Dry at 400℃ for 2h before use; Hydrochloric acid (GB/T622) solution: 0.1mol/L, 1mol/L; Sodium hydroxide (GB/T629) solution: 0.1mol/L; Ammonia water (GB/T631) 1mol/L ;
Methyl red (HG/T3-958) indicator solution: 1g/L, prepared according to 4.5.6 of GB/T603; Stock solution: A, B preparation method is as follows:
A solution: (Ca+) = 0.04mol/L
Accurately weigh 4.000g of calcium carbonate in an 800mL beaker, add a small amount of water to moisten, slowly add 82mL of 1mol/L hydrochloric acid solution, and stir well. After the calcium carbonate is completely dissolved, add 400mL of water, boil, remove carbon dioxide, cool to room temperature, add 2 drops of methyl red indicator solution, neutralize with ammonia water to orange, quantitatively transfer this solution to a 1000mL volumetric flask, dilute with water to the scale, and mix. Store in a polyethylene bottle for later use.
Solution B: c(Mg2+)=0.04mol/L
Accurately weigh 1.613g of magnesium oxide and place it in an 800mL beaker, add a small amount of water to moisten it, slowly add 82mL of 1mol/L hydrochloric acid solution, stir thoroughly and slowly heat. After the magnesium oxide is completely dissolved, add 400mL of water and boil it to remove carbon dioxide. Cool to room temperature and add 2 drops of methyl red indicator solution, neutralize it with ammonia water until it turns orange, transfer this solution to a 1000mL volumetric flask, dilute it with water to the scale, and mix it well. Store it in a polyethylene bottle for later use.
Standard hard water: 342mg in terms of calcium carbonate content. The preparation method is as follows: transfer 68.5mL of A solution and 17.0mL of B solution into a 1000mL beaker, add 800mL of water, drop 0.1mol/L sodium hydroxide solution or 0.1mol/L hydrochloric acid solution, and adjust the pH to 6.0~7.0 (measured with a pH meter). Transfer the solution to a 1000mL volumetric flask, dilute to the mark with water, and mix well.
A2.3 Apparatus
Graduating cylinder: 250mL, with ground glass stopper, 0~250mL scale is 20.0~21.5cm apart, the distance between the 250mL scale line and the bottom of the stopper should be 4~6cm;
Glass pipette: about 40cm long, with an inner diameter of about 5mm, with a hole of about 2~3mm at one end, and the other end of the tube is connected to the corresponding vacuum source.
Constant temperature water bath: 30±1℃;
Stopwatch.
A2.4 Determination steps
Weigh about 1g of sample (accurate to 0.0002g) and place it in a 200mL beaker filled with 50mL standard hard water (30±1℃). Shake it in a circular motion by hand, 120 times per minute, for 2min. Place the suspension in a water bath at the same temperature for 13min, then wash it all into a 250mL measuring cylinder with 30±1℃ standard hard water and dilute to the scale. Cover the stopper, and with the bottom of the measuring cylinder as the axis, turn the measuring cylinder upside down 30 times within 1min (turning the measuring cylinder upside down and returning it to its original position is one time, about 2s). Open the stopper, and then place it vertically in a vibration-free constant temperature water bath, place it for 30min, and use a pipette to remove 9/10 (i.e. 225mL) of the suspension in 1012s. Do not shake or stir up the sediment in the measuring cylinder, and ensure that the top of the pipette is always a few millimeters below the liquid surface. Use a pipette to accurately add 5 mL of internal standard solution to the 25 mL suspension at the bottom of the measuring cylinder, shake and extract thoroughly, let it stand, take the lower layer of organic solution for analysis, and determine the mass of the effective component in the suspension according to the prescribed method. A2.5 Calculation of the sample suspension rate Xs [% (m/m)) is calculated according to formula (A2): 10×ml-mz×100=111.1x
Xe-g×
Where: m1——the mass of the effective component in the sample taken to prepare the suspension,; m2——the mass of the effective component in the 25 mL suspension at the bottom of the measuring cylinder, g. Additional remarks:
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry. This standard is under the technical jurisdiction of the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. This standard is drafted by the Jiangsu Pesticide Research Institute. The main drafters of this standard are Yu Youfen, Yin Shangzheng, Liang Qinying, Xu Xiangsheng and Qiao Zhengfu. (A2)6uL;
Retention time: paclobutrazol, about 10min;
paclobutrazol I, about 12.3min;
dicyclohexyl phthalate, about 14.5min. The above operating conditions can be adjusted appropriately according to different instruments and chromatographic columns to obtain the best effect. A1.6 Determination steps
a. Preparation of standard solution
HG2614—94
Weigh 0.090g (accurate to 0.0002g) of paclobutrazol standard sample into a stoppered glass bottle, use a pipette to accurately add 10mL of internal standard solution, and shake well.
Preparation of sample solution
Weigh a sample containing about 0.090g (accurate to 0.0002g) of paclobutrazol into a stoppered glass bottle, accurately add 10mL of internal standard solution with a pipette, shake vigorously for 5 minutes, then pour the solution into a centrifuge test tube, centrifuge for 5 minutes (3500r.pm), take part of the clear liquid into a clean and dry glass bottle for testing.
c. Sample determination
Under the above operating conditions, after the instrument is stable, continuously inject several needles of standard solution, and after the relative response value of two adjacent needles changes by less than 1.5%, inject and analyze in the following order: a. Standard solution;
b Sample solution;
c. Sample solution;
Standard solution.
Figure 3 Gas chromatogram of paclobutrazol wettable powder 1-solvent, 2-chlorpyrifos; 3-paclobutrazol: 4-paclobutrazol 1; 5-dicyclohexyl phthalate A1.7 Calculation
Calculate the average value of the peak area ratio of paclobutrazol to internal standard in the two sample solutions and the two standard solutions before and after the sample, respectively, and the mass percentage X of paclobutrazol in the sample, according to formula (A1): Tamip
-average value of the peak area ratio of paclobutrazol to internal standard in the standard solution; In the formula: -
average value of the peak area ratio of paclobutrazol to internal standard in the sample solution; P2
-mass of standard sample, 8;
m2-mass of sample, g;
p-percentage content of standard sample, (m/m).
A1.8 Allowable error
The difference between two parallel determination results should not exceed 0.5%. A2 Determination of suspension rate
HG2614—94
A2.1 Method summary: Use standard hard water to prepare the sample to be tested into a suspension of appropriate concentration, the concentration of which should be the highest spraying concentration recommended for the wettable powder. Under the specified conditions, let it stand in the measuring cylinder for 30 minutes, determine the content of the active ingredient in the bottom tenth of the suspension, and calculate its suspension rate.
A2.2 Reagents
Magnesium oxide (GB/T9857): Dry at 150℃ for 2h before use; Calcium carbonate (HG/T3-1066): Dry at 400℃ for 2h before use; Hydrochloric acid (GB/T622) solution: 0.1mol/L, 1mol/L; Sodium hydroxide (GB/T629) solution: 0.1mol/L; Ammonia water (GB/T631) 1mol/L ;
Methyl red (HG/T3-958) indicator solution: 1g/L, prepared according to 4.5.6 of GB/T603; Stock solution: A, B preparation method is as follows:
A solution: (Ca+) = 0.04mol/L
Accurately weigh 4.000g of calcium carbonate in an 800mL beaker, add a small amount of water to moisten, slowly add 82mL of 1mol/L hydrochloric acid solution, and stir well. After the calcium carbonate is completely dissolved, add 400mL of water, boil, remove carbon dioxide, cool to room temperature, add 2 drops of methyl red indicator solution, neutralize with ammonia water to orange, quantitatively transfer this solution to a 1000mL volumetric flask, dilute with water to the scale, and mix. Store in a polyethylene bottle for later use.
Solution B: c(Mg2+)=0.04mol/L
Accurately weigh 1.613g of magnesium oxide and place it in an 800mL beaker, add a small amount of water to moisten it, slowly add 82mL of 1mol/L hydrochloric acid solution, stir thoroughly and slowly heat. After the magnesium oxide is completely dissolved, add 400mL of water and boil it to remove carbon dioxide. Cool to room temperature and add 2 drops of methyl red indicator solution, neutralize it with ammonia water until it turns orange, transfer this solution to a 1000mL volumetric flask, dilute it with water to the scale, and mix it well. Store it in a polyethylene bottle for later use.
Standard hard water: 342mg in terms of calcium carbonate content. The preparation method is as follows: transfer 68.5mL of A solution and 17.0mL of B solution into a 1000mL beaker, add 800mL of water, drop 0.1mol/L sodium hydroxide solution or 0.1mol/L hydrochloric acid solution, and adjust the pH to 6.0~7.0 (measured with a pH meter). Transfer the solution to a 1000mL volumetric flask, dilute to the mark with water, and mix well.
A2.3 Apparatus
Graduating cylinder: 250mL, with ground glass stopper, 0~250mL scale is 20.0~21.5cm apart, the distance between the 250mL scale line and the bottom of the stopper should be 4~6cm;
Glass pipette: about 40cm long, with an inner diameter of about 5mm, with a hole of about 2~3mm at one end, and the other end of the tube is connected to the corresponding vacuum source.
Constant temperature water bath: 30±1℃;
Stopwatch.
A2.4 Determination steps
Weigh about 1g of sample (accurate to 0.0002g) and place it in a 200mL beaker filled with 50mL standard hard water (30±1℃). Shake it in a circular motion by hand, 120 times per minute, for 2min. Place the suspension in a water bath at the same temperature for 13min, then wash it all into a 250mL measuring cylinder with 30±1℃ standard hard water and dilute to the scale. Cover the stopper, and with the bottom of the measuring cylinder as the axis, turn the measuring cylinder upside down 30 times within 1min (turning the measuring cylinder upside down and returning it to its original position is one time, about 2s). Open the stopper, and then place it vertically in a vibration-free constant temperature water bath, place it for 30min, and use a pipette to remove 9/10 (i.e. 225mL) of the suspension in 1012s. Do not shake or stir up the sediment in the measuring cylinder, and ensure that the top of the pipette is always a few millimeters below the liquid surface. Use a pipette to accurately add 5 mL of internal standard solution to the 25 mL suspension at the bottom of the measuring cylinder, shake and extract thoroughly, let it stand, take the lower layer of organic solution for analysis, and determine the mass of the effective component in the suspension according to the prescribed method. A2.5 Calculation of the sample suspension rate Xs [% (m/m)) is calculated according to formula (A2): 10×ml-mz×100=111.1x
Xe-g×
Where: m1——the mass of the effective component in the sample taken to prepare the suspension,; m2——the mass of the effective component in the 25 mL suspension at the bottom of the measuring cylinder, g. Additional remarks:
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry. This standard is under the technical jurisdiction of the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. This standard is drafted by the Jiangsu Pesticide Research Institute. The main drafters of this standard are Yu Youfen, Yin Shangzheng, Liang Qinying, Xu Xiangsheng and Qiao Zhengfu. (A2)6uL;
Retention time: paclobutrazol, about 10min;
paclobutrazol I, about 12.3min;
dicyclohexyl phthalate, about 14.5min. The above operating conditions can be adjusted appropriately according to different instruments and chromatographic columns to obtain the best effect. A1.6 Determination steps
a. Preparation of standard solution
HG2614—94
Weigh 0.090g (accurate to 0.0002g) of paclobutrazol standard sample into a stoppered glass bottle, accurately add 10mL of internal standard solution with a pipette, and shake well.
Preparation of sample solution
Weigh a sample containing about 0.090g (accurate to 0.0002g) of paclobutrazol into a stoppered glass bottle, accurately add 10mL of internal standard solution with a pipette, shake vigorously for 5 minutes, then pour the solution into a centrifuge test tube, centrifuge for 5 minutes (3500r.pm), take part of the clear liquid into a clean and dry glass bottle for testing.
c. Sample determination
Under the above operating conditions, after the instrument is stable, continuously inject several needles of standard solution, and after the relative response value of two adjacent needles changes by less than 1.5%, inject and analyze in the following order: a. Standard solution;
b Sample solution;
c. Sample solution;
Standard solution.
Figure 3 Gas chromatogram of paclobutrazol wettable powder 1-solvent, 2-chlorpyrifos; 3-paclobutrazol: 4-paclobutrazol 1; 5-dicyclohexyl phthalate A1.7 Calculation
Calculate the average value of the peak area ratio of paclobutrazol to internal standard in the two sample solutions and the two standard solutions before and after the sample, and the mass percentage X of paclobutrazol in the sample, according to formula (A1): Tamip
-average value of the peak area ratio of paclobutrazol to internal standard in the standard solution; In the formula: -
average value of the peak area ratio of paclobutrazol to internal standard in the sample solution; P2
-mass of standard sample, 8;
m2-mass of sample, g;
p-percentage content of standard sample, (m/m).
A1.8 Allowable error
The difference between two parallel determination results should not exceed 0.5%. A2 Determination of suspension rate
HG2614—94
A2.1 Method summary: Use standard hard water to prepare the sample to be tested into a suspension of appropriate concentration, the concentration of which should be the highest spraying concentration recommended for the wettable powder. Under the specified conditions, let it stand in the measuring cylinder for 30 minutes, determine the content of the active ingredient in the bottom tenth of the suspension, and calculate its suspension rate.
A2.2 Reagents
Magnesium oxide (GB/T9857): Dry at 150℃ for 2h before use; Calcium carbonate (HG/T3-1066): Dry at 400℃ for 2h before use; Hydrochloric acid (GB/T622) solution: 0.1mol/L, 1mol/L; Sodium hydroxide (GB/T629) solution: 0.1mol/L; Ammonia water (GB/T631) 1mol/L ;
Methyl red (HG/T3-958) indicator solution: 1g/L, prepared according to 4.5.6 of GB/T603; Stock solution: A, B preparation method is as follows:
Solution A: (Ca+) = 0.04mol/L
Accurately weigh 4.000g of calcium carbonate in an 800mL beaker, add a small amount of water to moisten, slowly add 82mL of 1mol/L hydrochloric acid solution, and stir well. After the calcium carbonate is completely dissolved, add 400mL of water, boil, remove carbon dioxide, cool to room temperature, add 2 drops of methyl red indicator solution, neutralize with ammonia water to orange, quantitatively transfer this solution to a 1000mL volumetric flask, dilute with water to the scale, and mix. Store in a polyethylene bottle for later use.
Solution B: c(Mg2+)=0.04mol/L
Accurately weigh 1.613g of magnesium oxide and place it in an 800mL beaker, add a small amount of water to moisten it, slowly add 82mL of 1mol/L hydrochloric acid solution, stir thoroughly and slowly heat. After the magnesium oxide is completely dissolved, add 400mL of water and boil it to remove carbon dioxide. Cool to room temperature and add 2 drops of methyl red indicator solution, neutralize it with ammonia water until it turns orange, transfer this solution to a 1000mL volumetric flask, dilute it with water to the scale, and mix it well. Store it in a polyethylene bottle for later use.
Standard hard water: 342mg in terms of calcium carbonate content. The preparation method is as follows: transfer 68.5mL of A solution and 17.0mL of B solution into a 1000mL beaker, add 800mL of water, drop 0.1mol/L sodium hydroxide solution or 0.1mol/L hydrochloric acid solution, and adjust the pH to 6.0~7.0 (measured with a pH meter). Transfer the solution to a 1000mL volumetric flask, dilute to the mark with water, and mix well.
A2.3 Apparatus
Graduating cylinder: 250mL, with ground glass stopper, 0~250mL scale is 20.0~21.5cm apart, the distance between the 250mL scale line and the bottom of the stopper should be 4~6cm;
Glass pipette: about 40cm long, with an inner diameter of about 5mm, with a hole of about 2~3mm at one end, and the other end of the tube is connected to the corresponding vacuum source.
Constant temperature water bath: 30±1℃;
Stopwatch.
A2.4 Determination steps
Weigh about 1g of sample (accurate to 0.0002g) and place it in a 200mL beaker filled with 50mL standard hard water (30±1℃). Shake it in a circular motion by hand, 120 times per minute, for 2min. Place the suspension in a water bath at the same temperature for 13min, then wash it all into a 250mL measuring cylinder with 30±1℃ standard hard water and dilute to the scale. Cover the stopper, and with the bottom of the measuring cylinder as the axis, turn the measuring cylinder upside down 30 times within 1min (turning the measuring cylinder upside down and returning it to its original position is one time, about 2s). Open the stopper, and then place it vertically in a vibration-free constant temperature water bath, place it for 30min, and use a pipette to remove 9/10 (i.e. 225mL) of the suspension in 1012s. Do not shake or stir up the sediment in the measuring cylinder, and ensure that the top of the pipette is always a few millimeters below the liquid surface. Use a pipette to accurately add 5 mL of internal standard solution to the 25 mL suspension at the bottom of the measuring cylinder, shake and extract thoroughly, let it stand, take the lower layer of organic solution for analysis, and determine the mass of the effective component in the suspension according to the prescribed method. A2.5 Calculation of the sample suspension rate Xs [% (m/m)) is calculated according to formula (A2): 10×ml-mz×100=111.1x
Xe-g×
Where: m1——the mass of the effective component in the sample taken to prepare the suspension,; m2——the mass of the effective component in the 25 mL suspension at the bottom of the measuring cylinder, g. Additional remarks:
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry. This standard is under the technical jurisdiction of the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. This standard is drafted by the Jiangsu Pesticide Research Institute. The main drafters of this standard are Yu Youfen, Yin Shangzheng, Liang Qinying, Xu Xiangsheng and Qiao Zhengfu. (A2)7 Calculation
Calculate the average value of the peak area ratio of paclobutrazol to the internal standard in the two sample solutions and the two standard solutions before and after the sample, respectively, and calculate the mass percentage of paclobutrazol in the sample X according to formula (A1): Tamip
-average value of the peak area ratio of paclobutrazol to the internal standard in the standard solution; Where: -
average value of the peak area ratio of paclobutrazol to the internal standard in the sample solution; P2
-mass of the standard, 8;
m2-mass of the sample, g;
p-percentage of the standard, (m/m).
A1.8 Allowable error
The difference between the results of two parallel determinations should not be greater than 0.5%. A2 Determination of suspension rate
HG2614—94
A2.1 Method summary: Use standard hard water to prepare the sample to be tested into a suspension of appropriate concentration, the concentration of which should be the highest spraying concentration recommended for the wettable powder. Under the specified conditions, let it stand in the measuring cylinder for 30 minutes, determine the content of the effective ingredient in the bottom tenth of the suspension, and calculate its suspension rate.
A2.2 Reagents
Magnesium oxide (GB/T9857): Dry at 150℃ for 2h before use Calcium carbonate (HG/T3-1066): Dry at 400℃ for 2h before use; Hydrochloric acid (GB/T622) solution: 0.1mol/L, 1mol/L; Sodium hydroxide (GB/T629) solution: 0.1mol/L; Ammonia water (GB/T631) 1mol/L ;
Methyl red (HG/T3-958) indicator solution: 1g/L, prepared according to 4.5.6 of GB/T603; Stock solution: A, B preparation method is as follows:
Solution A: (Ca+) = 0.04mol/L
Accurately weigh 4.000g of calcium carbonate in an 800mL beaker, add a small amount of water to moisten, slowly add 82mL of 1mol/L hydrochloric acid solution, and stir well. After the calcium carbonate is completely dissolved, add 400mL of water, boil, remove carbon dioxide, cool to room temperature, add 2 drops of methyl red indicator solution, neutralize with ammonia water to orange, quantitatively transfer this solution to a 1000mL volumetric flask, dilute with water to the scale, and mix. Store in a polyethylene bottle for later use.
Solution B: c(Mg2+)=0.04mol/L
Accurately weigh 1.613g of magnesium oxide and place it in an 800mL beaker, add a small amount of water to moisten it, slowly add 82mL of 1mol/L hydrochloric acid solution, stir thoroughly and slowly heat. After the magnesium oxide is completely dissolved, add 400mL of water and boil it to remove carbon dioxide. Cool to room temperature and add 2 drops of methyl red indicator solution, neutralize it with ammonia water until it turns orange, transfer this solution to a 1000mL volumetric flask, dilute it with water to the scale, and mix it well. Store it in a polyethylene bottle for later use.
Standard hard water: 342mg in terms of calcium carbonate content. The preparation method is as follows: transfer 68.5mL of A solution and 17.0mL of B solution into a 1000mL beaker, add 800mL of water, drop 0.1mol/L sodium hydroxide solution or 0.1mol/L hydrochloric acid solution, and adjust the pH to 6.0~7.0 (measured with a pH meter). Transfer the solution to a 1000mL volumetric flask, dilute to the mark with water, and mix well.
A2.3 Apparatus
Graduating cylinder: 250mL, with ground glass stopper, 0~250mL scale is 20.0~21.5cm apart, the distance between the 250mL scale line and the bottom of the stopper should be 4~6cm;
Glass pipette: about 40cm long, with an inner diameter of about 5mm, with a hole of about 2~3mm at one end, and the other end of the tube is connected to the corresponding vacuum source.
Constant temperature water bath: 30±1℃;
Stopwatch.
A2.4 Determination steps
Weigh about 1g of sample (accurate to 0.0002g) and place it in a 200mL beaker filled with 50mL standard hard water (30±1℃). Shake it in a circular motion by hand, 120 times per minute, for 2min. Place the suspension in a water bath at the same temperature for 13min, then wash it all into a 250mL measuring cylinder with 30±1℃ standard hard water and dilute to the scale. Cover the stopper, and with the bottom of the measuring cylinder as the axis, turn the measuring cylinder upside down 30 times within 1min (turning the measuring cylinder upside down and returning it to its original position is one time, about 2s). Open the stopper, and then place it vertically in a vibration-free constant temperature water bath, place it for 30min, and use a pipette to remove 9/10 (i.e. 225mL) of the suspension in 1012s. Do not shake or stir up the sediment in the measuring cylinder, and ensure that the top of the pipette is always a few millimeters below the liquid surface. Use a pipette to accurately add 5 mL of internal standard solution to the 25 mL suspension at the bottom of the measuring cylinder, shake and extract thoroughly, let it stand, take the lower layer of organic solution for analysis, and determine the mass of the effective component in the suspension according to the prescribed method. A2.5 Calculation of the sample suspension rate Xs [% (m/m)) is calculated according to formula (A2): 10×ml-mz×100=111.1x
Xe-g×
Where: m1——the mass of the effective component in the sample taken to prepare the suspension,; m2——the mass of the effective component in the 25 mL suspension at the bottom of the measuring cylinder, g. Additional remarks:
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry. This standard is under the technical jurisdiction of the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. This standard is drafted by the Jiangsu Pesticide Research Institute. The main drafters of this standard are Yu Youfen, Yin Shangzheng, Liang Qinying, Xu Xiangsheng and Qiao Zhengfu. (A2)7 Calculation
Calculate the average value of the peak area ratio of paclobutrazol to the internal standard in the two sample solutions and the two standard solutions before and after the sample, respectively, and calculate the mass percentage of paclobutrazol in the sample X according to formula (A1): Tamip
-average value of the peak area ratio of paclobutrazol to the internal standard in the standard solution; Where: -
average value of the peak area ratio of paclobutrazol to the internal standard in the sample solution; P2
-mass of the standard, 8;
m2-mass of the sample, g;
p-percentage of the standard, (m/m).
A1.8 Allowable error
The difference between the results of two parallel determinations should not be greater than 0.5%. A2 Determination of suspension rate
HG2614—94
A2.1 Method summary: Use standard hard water to prepare the sample to be tested into a suspension of appropriate concentration, the concentration of which should be the highest spraying concentration recommended for the wettable powder. Under the specified conditions, let it stand in the measuring cylinder for 30 minutes, determine the content of the effective ingredient in the bottom tenth of the suspension, and calculate its suspension rate.
A2.2 Reagents
Magnesium oxide (GB/T9857): Dry at 150℃ for 2h before use Calcium carbonate (HG/T3-1066): Dry at 400℃ for 2h before use; Hydrochloric acid (GB/T622) solution: 0.1mol/L, 1mol/L; Sodium hydroxide (GB/T629) solution: 0.1mol/L; Ammonia water (GB/T631) 1mol/L ;
Methyl red (HG/T3-958) indicator solution: 1g/L, prepared according to 4.5.6 of GB/T603; Stock solution: A, B preparation method is as follows:
A solution: (Ca+) = 0.04mol/L
Accurately weigh 4.000g of calcium carbonate in an 800mL beaker, add a small amount of water to moisten, slowly add 82mL of 1mol/L hydrochloric acid solution, and stir well. After the calcium carbonate is completely dissolved, add 400mL of water, boil, remove carbon dioxide, cool to room temperature, add 2 drops of methyl red indicator solution, neutralize with ammonia water to orange, quantitatively transfer this solution to a 1000mL volumetric flask, dilute with water to the scale, and mix. Store in a polyethylene bottle for later use.
Solution B: c(Mg2+)=0.04mol/L
Accurately weigh 1.613g of magnesium oxide and place it in an 800mL beaker, add a small amount of water to moisten it, slowly add 82mL of 1mol/L hydrochloric acid solution, stir thoroughly and slowly heat. After the magnesium oxide is completely dissolved, add 400mL of water and boil it to remove carbon dioxide. Cool to room temperature and add 2 drops of methyl red indicator solution, neutralize it with ammonia water until it turns orange, transfer this solution to a 1000mL volumetric flask, dilute it with water to the scale, and mix it well. Store it in a polyethylene bottle for later use.
Standard hard water: 342mg in terms of calcium carbonate content. The preparation method is as follows: transfer 68.5mL of A solution and 17.0mL of B solution into a 1000mL beaker, add 800mL of water, drop 0.1mol/L sodium hydroxide solution or 0.1mol/L hydrochloric acid solution, and adjust the pH to 6.0~7.0 (measured with a pH meter). Transfer the solution to a 1000mL volumetric flask, dilute to the mark with water, and mix well.
A2.3 Apparatus
Graduating cylinder: 250mL, with ground glass stopper, 0~250mL scale is 20.0~21.5cm apart, the distance between the 250mL scale line and the bottom of the stopper should be 4~6cm;
Glass pipette: about 40cm long, with an inner diameter of about 5mm, with a hole of about 2~3mm at one end, and the other end of the tube is connected to the corresponding vacuum source.
Constant temperature water bath: 30±1℃;
Stopwatch.
A2.4 Determination steps
Weigh about 1g of sample (accurate to 0.0002g) and place it in a 200mL beaker filled with 50mL standard hard water (30±1℃). Shake it in a circular motion by hand, 120 times per minute, for 2min. Place the suspension in a water bath at the same temperature for 13min, then wash it all into a 250mL measuring cylinder with 30±1℃ standard hard water and dilute to the scale. Cover the stopper, and with the bottom of the measuring cylinder as the axis, turn the measuring cylinder upside down 30 times within 1min (turning the measuring cylinder upside down and returning it to its original position is one time, about 2s). Open the stopper, and then place it vertically in a vibration-free constant temperature water bath, place it for 30min, and use a pipette to remove 9/10 (i.e. 225mL) of the suspension in 1012s. Do not shake or stir up the sediment in the measuring cylinder, and ensure that the top of the pipette is always a few millimeters below the liquid surface. Use a pipette to accurately add 5 mL of internal standard solution to the 25 mL suspension at the bottom of the measuring cylinder, shake and extract thoroughly, let it stand, take the lower layer of organic solution for analysis, and determine the mass of the effective component in the suspension according to the prescribed method. A2.5 Calculation of the sample suspension rate Xs [% (m/m)) is calculated according to formula (A2): 10×ml-mz×100=111.1x
Xe-g×
Where: m1——the mass of the effective component in the sample taken to prepare the suspension,; m2——the mass of the effective component in the 25 mL suspension at the bottom of the measuring cylinder, g. Additional remarks:
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry. This standard is under the technical jurisdiction of the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. This standard is drafted by the Jiangsu Pesticide Research Institute. The main drafters of this standard are Yu Youfen, Yin Shangzheng, Liang Qinying, Xu Xiangsheng and Qiao Zhengfu. (A2)0002g) is placed in a 200mL beaker containing 50mL of standard hard water (30±1℃), and shaken by hand in a circular motion at 120 times per minute for 2min. The suspension is placed in a water bath at the same temperature for 13min, and then washed into a 250mL measuring cylinder with 30±1℃ standard hard water, and diluted to the scale, covered with a stopper, and with the bottom of the measuring cylinder as the axis, the measuring cylinder is turned upside down 30 times within 1min (inverting the measuring cylinder and returning it to its original position is one time, about 2s). Open the stopper, and then vertically place it in a constant temperature water bath without vibration, and place it for 30min. Use a pipette to remove 9/10 (i.e. 225mL) of the suspension in 1012s. Do not shake or stir up the sediment in the measuring cylinder, and ensure that the top of the pipette is always a few millimeters below the liquid surface. Use a pipette to accurately add 5 mL of internal standard solution to the 25 mL suspension at the bottom of the measuring cylinder, shake and extract thoroughly, let it stand, take the lower layer of organic solution for analysis, and determine the mass of the effective component in the suspension according to the prescribed method. A2.5 Calculation of the sample suspension rate Xs [% (m/m)) is calculated according to formula (A2): 10 × ml-mz × 100 = 111.1x
Xe-g ×
Where: m1——the mass of the effective component in the sample taken to prepare the suspension,; m2——the mass of the effective component in the 25 mL suspension at the bottom of the measuring cylinder, g. 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 Industry Research Institute of the Ministry of Chemical Industry. This standard was drafted by the Jiangsu Pesticide Research Institute. The main drafters of this standard are Yu Youfen, Yin Shangzheng, Liang Qinying, Xu Xiangsheng and Qiao Zhengfu. (A2)0002g) is placed in a 200mL beaker containing 50mL of standard hard water (30±1℃), and shaken by hand in a circular motion at 120 times per minute for 2min. The suspension is placed in a water bath at the same temperature for 13min, and then washed into a 250mL measuring cylinder with 30±1℃ standard hard water, and diluted to the scale, covered with a stopper, and with the bottom of the measuring cylinder as the axis, the measuring cylinder is turned upside down 30 times within 1min (inverting the measuring cylinder and returning it to its original position is one time, about 2s). Open the stopper, and then vertically place it in a constant temperature water bath without vibration, and place it for 30min. Use a pipette to remove 9/10 (i.e. 225mL) of the suspension within 1012s. Do not shake or stir up the sediment in the measuring cylinder, and ensure that the top of the pipette is always a few millimeters below the liquid surface. Use a pipette to accurately add 5 mL of internal standard solution to the 25 mL suspension at the bottom of the measuring cylinder, shake and extract thoroughly, let it stand, take the lower layer of organic solution for analysis, and determine the mass of the effective component in the suspension according to the prescribed method. A2.5 Calculation of the sample suspension rate Xs [% (m/m)) is calculated according to formula (A2): 10×ml-mz×100=111.1x
Xe-g×
Where: m1——the mass of the effective component in the sample taken to prepare the suspension,; m2——the mass of the effective component in the 25 mL suspension at the bottom of the measuring cylinder, g. Additional remarks:
This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry. This standard is under the technical jurisdiction of the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. This standard is drafted by the Jiangsu Pesticide Research Institute. The main drafters of this standard are Yu Youfen, Yin Shangzheng, Liang Qinying, Xu Xiangsheng and Qiao Zhengfu. (A2)
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