Some standard content:
Chemical Industry Standard of the People's Republic of China
HG2169—91
Chlorotoluron Wettable Powder
Published on November 18, 1991
Ministry of Chemical Industry of the People's Republic of China
Implemented on May 1, 1992
Chemical Industry Standard of the People's Republic of China
Chlorotoluron Wettable Powder
Subject Content and Scope of Application
HG2169—91
This standard specifies the technical requirements, test methods, inspection rules, and marking, packaging, transportation and storage requirements for 25% chlorotoluron wettable powder.
This standard applies to chlorotoluron wettable powders made by processing chlorotoluron technical with surfactants, fillers, etc. Active ingredient: chlorotoluron.
Chemical name, 3 (3-chloro-4-p-tolyl) -1,1-dimethylurea Structural formula:
Molecular formula: C1H1:CIN20
-NHCN(CH,)2
Relative molecular weight: 212.7 (according to the 1987 international relative atomic mass) 2 Reference standards
Preparation of standard solution for titration analysis (volume analysis) of chemical reagents GB1600
GB1601
GB1605
GB3796
GB5451
Determination of moisture content in pesticides
Determination of hydrogen ion concentration in pesticides
Sampling method for commercial pesticides
General rules for pesticide packaging
Determination of wettability of wettable powders of pesticides HG 2—896
3 Technical requirements
Method for determining the fineness of pesticide powders
3.1 Appearance: Off-white to yellow-brown loose powder, without lumps. 3.2 The chlorotoluron wettable powder shall meet the technical requirements in the following table: Item
Chlorotoluron content (m/m), %
Suspension rate (m/m), %
Fineness (through 43um sieve) (m/m), %
Approved by the Ministry of Chemical Industry of the People's Republic of China on November 18, 1991>
Implemented on May 1, 1992
Wetting time, min
Water content (m/m), %
4 Test method
4.1 Determination of chlorotoluron content
4.1.1 High performance liquid chromatography (arbitration method) 4.1.1.1 Summary of method
HG216991
The sample is dissolved in methanol, separated by a C18 reversed phase liquid chromatography column and determined by a UV detector. The mobile phase is methanol and water, and the chlorotoluron content is determined by the external standard method.
4.1.1.2 Reagents and solutions
Methanol (GB683);
Glacial acetic acid (GB676);
Chlorotoluron standard sample: known content.
4.1.1.3 Instruments
High performance liquid chromatograph: with adjustable wavelength UV detector; Chromatographic column: Bondapau MrC18, 250mm long, 4.6mm inner diameter stainless steel column; Data processor or recorder;
Micro syringe: 10uL.
4.1.1.4 Operating conditions
Detection wavelength: 243nm (or 245nm)
Detection sensitivity: 0.5AUFS;
Column temperature: room temperature;
Mobile phase: formic acid + water + glacial acetic acid = 60+40+0.1 (V/V): flow rate: 1mL/min;
Retention time: about 10min for chlorotoluron.
4.1.1.5 Operating steps
4.1.1.5.1 Preparation of standard solution
Weigh about 0.1g (accurate to 0.0001g) of chlorotoluron standard sample, place it in a 100mL volumetric flask, dissolve it with methanol, oscillate it on an ultrasonic generator for 15min, then dilute it to the scale with methanol and shake it well. 4.1.1.5.2 Preparation of sample solution
Weigh a sample containing about 0.1g (accurate to 0.0001g) of green wheatgrass, place it in a 100mL volumetric flask, dissolve it with methanol, dilute it to the mark with methanol, and shake it. Centrifuge the solution before injection, and take the supernatant for injection. 4.1.1.5.3 Determination
Under the chromatographic conditions specified in 4.1.1.4, after the instrument is stable, first inject several injections of standard solution until the relative deviation of the peak area (or peak height) of two consecutive injections is no more than 1%, and then perform quantitative analysis. It takes about 30 minutes for all components of the sample solution to flow out. Inject and analyze in the following order:
a. Standard solution;
Sample solution;
c. Sample solution;
Standard solution.
4.1.1.5.4 Calculation
HG2169--91
Figure 1 High Performance Liquid Chlorotoluron Chlorotoluron Chlorotoluron HPLC Chlorotoluron 1 Standard sample; 2—Chlorotoluron wettable powder
According to the average value of the peak area (or peak height) of the two standard sample solutions a and d and the two sample solutions b and c, calculate the mass percentage of chlorotoluron in the sample according to formula (1) 1:1
Wherein: A1—average value of the peak area (or peak height) of the sample solution; A2—average value of the peak area (or peak height) of the standard solution; mi
—mass of chlorotoluron wettable powder sample, g;—mass of chlorotoluron standard sample, g,
w—mass percentage of chlorotoluron standard sample, %. 4.1.1.5.5 Allowable Difference
The difference between the parallel determination results of this method shall not exceed 0.5%. 4.1.2 Thin layer-ultraviolet spectrophotometry
4.1.2.1 Summary of the method
After the sample is separated by thin layer, take the silica gel layer containing the chlorotoluron band, elute it with solvent, and use ultraviolet spectrophotometer for quantitative determination. 4.1.2.2 Reagents and solutions
95% ethanol (GB679);
Chloroform (GB682);
Ethyl acetate (HG3-1226);
Developing agent: chloroform + ethyl acetate = 80 + 20 (V/v); silica gel GF254: for chromatography.
4.1.2.3 Instruments
Ultraviolet spectrophotometer: equipped with 1cm quartz colorimetric cell; ultraviolet lamp: wavelength 254nm.
4.1.2.4 Determination
4.1.2.4.1 Preparation of thin layer plate
HG216991
Weigh 7.5g silica gel GF254, add 19mL of distilled water in a glass mortar, grind to a uniform paste, and immediately pour it on a pre-cleaned and dried 10cm×20cm glass plate, and gently vibrate to make the silica gel evenly distributed on the plate without bubbles. Place it horizontally to air dry naturally, then move it to an oven, activate it at 120150℃ for 1h, take it out and put it in a desiccator for use. 4.1.2.4.2 Preparation of standard solution
Weigh about 0.05g (accurate to 0.0001g) of green wheat standard sample, place it in a 50mL volumetric flask, dissolve it with 30mL of chloroform, oscillate it in an ultrasonic water bath for 15min, and then dilute it to the scale with chloroform. After shaking, accurately pipette 10mL of the solution into a 25mL volumetric flask, dilute to scale with chloroform, and shake well. 4.1.2.4.3 Preparation of sample solution
Weigh a sample containing about 0.1g (accurate to 0.0001g) of chlorotoluron, dissolve it in 30mL of chloroform, oscillate in an ultrasonic water bath for 15min, filter and wash it into a 50mL volumetric flask, and dilute to scale with chloroform. Shake well. Accurately pipette 10mL of the solution into a 25mL volumetric flask, dilute to scale with chloroform, and shake well. 4.1.2.4.4 Chromatography
Use a 0.5mL pipette to accurately draw 0.3mL of the above standard solution and sample solution respectively. On the activated chromatography plate, place the standard solution and sample solution in a straight line 2cm from the bottom and 1.5cm on both sides. Let the solvent evaporate. Place the plate in a developing cylinder filled with saturated vapor of the developing agent at room temperature. The depth of the plate immersed in the solvent is about 1cm. When the development front rises to about 14cm from the dot line, take out the plate. After the developing agent evaporates, color it under ultraviolet light. Transfer the band of Rt=0.4 on the plate completely to a glass funnel (lay two layers of qualitative filter paper in the funnel), elute it with 20mL95% ethanol in multiple times (56 times) into a 25mL volumetric flask, then dilute it to the scale with ethanol and shake it well. 4.1.2.4.5 Determination
Use 95% ethanol as a reference and determine the absorbance of the standard solution and sample solution at a wavelength of 250nm. 4.1.2.4.6 Calculation
The mass percentage of chlorotoluron in the sample? Calculate according to formula (2): A·mz·w
A2·m1
Wherein: Ai——absorbance of sample solution; A2——absorbance of standard solution;
m1——mass of sample, g;
m2——mass of chlorotoluron standard sample, g;
mass percentage of chlorotoluron standard sample, %. 4.1.2.4.7 Allowable difference
The difference between the parallel determination results of this method shall not exceed 0.5%. 4.1.3 Chemical-thin layer method
4.1.3.1 Summary of method
The sample is dissolved in dichloromethane, and the free amine is extracted with hydrochloric acid. The dichloromethane is evaporated and the residue is hydrolyzed with potassium hydroxide 1,2-propylene glycol solution. The released amine is absorbed with boric acid solution and titrated with hydrochloric acid standard solution to obtain the total amine content. Subtract the contents of byproduct I [3-(3-chloro-4-methylphenyl)-1-methylurea] and byproduct I [3-(4-methylphenyl)-1,1-dimethylurea] determined by thin layer chromatography to obtain the content of chlorotoluron.
The reaction equation is as follows:
Reagents and solutions
Boric acid (GB628);
1,2-propylene glycol;
Dichloromethane;
N(CHa)2
N(CHs)2
HG2169—-91
+ 2KOH = CHs
+2KOH=CHs
+2KOH=CHs
NH2+NH(CH)2+K,CO3
-NH,+NH,CH+K,COs
NHz+NH(CH)2+K,COs
NH(CHs)2+HCI-NH2(CH:)2CI
NH,CH:+HCI=NH.CH:CI
Hydrochloric acid (GB622) solution: c(HCI)=1mol/L. Hydrochloric acid (GB622) standard titration solution: c(HCI)=1.000mol/L;Methyl red-methylene blue mixed indicator solution: Weigh 60mg methyl red and 40mg methylene blue and dissolve them in 100mL95% ethanol. 4.1.3.3 Apparatus
Electromagnetic stirrer;
Rotary evaporator,
250mL separating funnel with glass stopper and stopcock; Distillation apparatus with ground joint (see Figure 2); Burette; 25mL acid burette with 0.05 graduation. 5
4.1.3.4 Determination steps
HG2169--91
Figure 2 Diagram of distillation apparatus
1—Heating jacket; 2—500mL round bottom flask; 3—Reflux tube; 4—Dropping funnel; 5 Buffer cover, 6—Condenser 7—400mL beaker, 8—Electromagnetic stirrer Weigh 12g (accurate to 0.0001g) of 25% wettable powder sample, put it in a 200mL beaker, add 100mL dichloromethane, stir on the electromagnetic stirrer for 5min, and pass through a sintered glass Filter in a glass crucible, rinse the beaker and with dichloromethane, transfer the extract to a 500mL separatory funnel, add 50mL hydrochloric acid [c (HC1) = 1mol/L), shake for 30s, place the organic layer in a second separatory funnel, add 50mL hydrochloric acid [c (HCl) = 1mol/L), shake for 30s, place the organic layer in a 500mL round-bottom flask, wash the water layers in the above two funnels continuously with a total volume of 200mL of dichloromethane, combine the organic layers in the flask, and discard the aqueous solution. Evaporate dichloromethane to dryness in a rotary evaporator (the maximum temperature of the water bath is 40℃). Add 100mL 1,2-propylene glycol, 40g potassium hydroxide and some zeolite to the residue, and immediately connect the flask tightly to the distillation device. Apply a thin layer of silicone grease to all joints. Add 150mL of distilled water, 0.2g of boric acid and 1.0mL of mixed indicator to the beaker. The end of the catheter should be placed below the liquid surface. Warm the flask to dissolve all the potassium hydroxide and chlorotoluron, then boil for 10 minutes, reflux 1,2-propylene glycol in the condenser and add water from the separatory funnel to the boiling material in the flask at a rate of 1 drop/s to complete the distillation of the amine. At the same time, titrate the amine with a standard hydrochloric acid titration solution, and continue to titrate until the color of the indicator changes from green to blue and remains unchanged for 2 minutes. At the same time, perform a blank test under the same conditions. 4.1.3.5 Calculation of the mass percentage of chlorotoluron. Calculate according to formula (3): s
(V1V2)·cX0.2127
HG216991
Wherein: V is the volume of the standard hydrochloric acid titration solution consumed by the sample, mL; V2 is the volume of the standard hydrochloric acid titration solution consumed by the blank, mL; c is the actual concentration of the standard hydrochloric acid titration solution, mol/L; m is the mass of the sample, g;
0.2127 is the mass of chlorotoluron in grams equivalent to 1.00 mL of the standard hydrochloric acid titration solution Cc(HC1)=1.000 mol/L]; 34 is the by-product content, see Article 4.1.4 of this standard, % (m/m). 4.1.3.6 Allowable difference
The difference between the two determination results shall not be greater than 1%
4.1.4 Determination of by-products 1 and I
This thin layer chromatography method can determine the content of two possible by-products (I and I) that interfere with the determination of chlorotoluron. 4.1.4.1 Summary of the method
The sample and the standard sample solution of the by-product are separated by thin layer chromatography. Under ultraviolet light, the spots produced by the sample and the standard sample solution of by-products I and I are compared to determine their mass percentage content. 4.1.4.2 Reagents
Standard sample of byproduct I [3-(3-chloro-4-methylphenyl)-1-methylurea, known content; Standard sample of byproduct I {3-(4-methylphenyl)-1,1-dimethylurea}, known content; Chloroform (GB682);
Ethyl acetate (HG3-1226)
Tetrahydrofuran;
Developing solvent: Chloroform + Ethyl acetate = 80 + 20 (V/V); Silica gel HF254: for chromatography.
4.1.4.3 Apparatus
Developing cylinder:
Glass plate: 20cm×20cm;
Pipette: 5mL, 0.05 division;
Volume flask: 50mL, 10mL,
Ultraviolet lamp: wavelength 254nm.
4.1.4.4 Determination
4.1.4.4.1 Preparation of thin layer plate
Weigh 8g silica gel HF254, place in a glass mortar, add 23mL of distilled water, grind to a uniform paste, immediately pour on a pre-cleaned and dried chromatography glass plate, and gently vibrate to make the silica gel evenly distributed on the plate without bubbles. Place the plate horizontally and let it air flow naturally, then move it to an oven, activate it at 140℃ for 2h, take it out and place it in a desiccator for use. 4.1.4.4.2 Preparation of sample solution
Weigh 0.5g (accurate to 0.0001g) of sample into a 10mL volumetric flask, dissolve it with tetrahydrofuran and dilute it to the scale, and shake it well. 4.1.4.4.3 Preparation of by-product standard solution Weigh 50±1mg of by-products I and I respectively into a 50mL volumetric flask, dissolve it with tetrahydrofuran and dilute it to the scale, and shake it well. Use a pipette to draw 1.0, 2.0, 3.0, 4.0 and 5.0 mL of the above solution into five 10 mL volumetric flasks respectively, and dilute to the mark with tetrahydrofuran. The corresponding mass percentages are 0.2%, 0.4%, 0.6%, 0.8% and 1.0% respectively. 4.1.4.4.4 Chromatography
On the same thin layer chromatography plate, use a 5uL syringe to draw 5uL of the standard sample solution of the by-product (in order of concentration from low to high) and the sample solution side by side on the plate 2.5cm from the bottom and 1.5cm on both sides. Let the solvent evaporate and place it in a developing cylinder saturated with the developing agent vapor at room temperature for 30 minutes. When the front edge of the developing agent rises to about 13cm above the spot line (about 70 minutes), take it out. After the developing agent evaporates, compare the spots produced by the sample solution and the by-product standard solution at Rt values of about 0.25 and 0.35 on the chromatography plate under ultraviolet light. When the by-product in the sample solution is consistent with the spot of the by-product in the standard solution of a certain by-product, it is the mass percentage of the by-product. 4.1.4.4.5 When the by-product content of the sample solution exceeds 1%, dilute the sample solution to the mass percentage range of the by-product standard solution, and then measure according to 4.1.4.4.4. 4.2 Determination of suspension rate
4.2.1 Method summary
Use standard hard water to prepare a suspension of known concentration. Under specified conditions, determine the content of chlorotoluron in the bottom 1/10 of the suspension and calculate the suspension rate of the sample.
4.2.2 Reagents and solutions
Standard hard water: 342ppm. Prepared according to the provisions of GB5451; Hydrochloric acid (GB622) standard titration solution: c(HCI)=0.1mol/L, prepared and calibrated according to GB601. 4.2.3 ApparatusbZxz.net
Measuring cylinder with stopper: the distance between the 0~250mL scales should be 20.0~21.5cm, and the distance between the 250mL scale and the bottom of the stopper should be 4~6cm;
Glass pipette: about 40cm long, with an inner diameter of about 5mm, a 23mm hole at the tip of one end, and the other end of the tube connected to the corresponding exhaust source,
Glass constant temperature water bath: 30±1℃;
4.2.4 Determination
Weigh a sample containing about 1.5g of green wheat germ (accurate to 0.001g) in a 100mL beaker, add 10mL of standard hard water, shake the beaker, and after the sample is self-wetted, add 50mL of standard hard water (30±1C) dropwise while stirring, and place the suspension in a water bath at the same temperature for 13min. Then wash it all into a 250mL stoppered measuring cylinder with 30±1℃ standard hard water, dilute to the mark, and cover with stopper. Invert the measuring cylinder 30 times within 1 minute, then vertically place it in a constant temperature water bath without vibration, open the stopper, and leave it for 30 minutes. Use a pipette to remove 9/10 (i.e. 225mL) of the suspension in 10~15 seconds. Do not shake or stir the sediment in the measuring cylinder, and ensure that the top of the pipette is always a few millimeters below the liquid surface. Pour the remaining part in the measuring cylinder into a 250mL separatory funnel. Wash the measuring cylinder three times with 50mL of dichloromethane. Transfer all the precipitates into the separatory funnel, add 5mL of hydrochloric acid [c(HCI)=1mol/LJ, extract three times with 100mL of dichloromethane, put the organic layer into the required container, evaporate the dichloromethane to dryness, and determine the mass m2 of chlorotoluron in the bottom 1/10 of the suspension according to the steps in 4.1. 4.2.5 Calculation
The suspension rate 6 of the sample is calculated according to formula (4):
mim2y10
Where: m1——the mass of chlorotoluron in the sample of the prepared suspension, g; m2——the mass of chlorotoluron in the bottom 1/10 of the suspension calculated according to the different methods taken in 4.1, g. 4.2.6 Permissible difference
The difference between the results of two parallel determinations in this method should not be greater than 5.0%. 4.3 Determination of fineness
Determine according to the wet sieving method in HG2-896.
4.4 Determination of wetting time
Determine according to the method in GB5451.
4.5 Determination of pH value
Determine according to the pH meter method in GB1601.
5 Inspection rules
5.125% Chlorotoluron wettable powder shall be inspected by the quality supervision and inspection department of the manufacturer. The manufacturer shall ensure that all 8
HG2169--91
25% Chlorotoluron wettable powder shipped out of the factory meets the requirements of this standard. Each batch of Chlorotoluron wettable powder shipped out of the factory shall be accompanied by a quality certificate in a certain format.
5.2 The user has the right to inspect the quality of the received Chlorotoluron wettable powder in accordance with the provisions of this standard to check whether it meets the requirements of this standard.
5.3 Sampling method: It can be carried out according to the sampling method of wettable powder in GB1605. Mix the samples evenly and put them into two clean, dry glass bottles with ground stoppers. Label the bottles with the manufacturer's name, product name, batch number and sampling date. One bottle is sent to the quality supervision and inspection department for inspection and the other bottle is sealed. 5.4 In the test results, if some indicators do not meet the requirements of this standard, samples should be taken from twice the amount of packaging for re-testing. If only one indicator does not meet the requirements of this standard, the whole batch of chlorotoluron wettable powder is unqualified. 5.5 When the supply and demand parties have disputes over quality, they can be resolved through negotiation, or the statutory inspection agency can conduct arbitration analysis according to the inspection method specified in this standard.
6 Marking, packaging, transportation and purchase and storage
6.1 The marking and packaging of chlorotoluron wettable powder should comply with the relevant provisions of GB3769. 6.2 Chlorotoluron wettable powder is packaged in sealed plastic film bags, with the net weight of each bag not exceeding 500g. A certain number of small bags are tightly arranged in a box, with the net weight of each box not exceeding 25kg (other forms of packaging can also be used according to user requirements). 6.3 During storage and transportation, it should be strictly protected from moisture and sunlight, and maintained with good ventilation; it should not be mixed with food, seeds and feed, and should avoid contact with the skin and prevent inhalation through the mouth and nose.
Additional instructions:
This standard was proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the technical jurisdiction of the Shenyang Chemical Research Institute of the Ministry of Chemical Industry. This standard was drafted by the Shenyang Chemical Research Institute of the Ministry of Chemical Industry and the Pesticide Testing Institute of the Ministry of Agriculture. The main drafters of this standard are Jia Lijun, Ma Yaguang, Zhang Baizhen, Wang Yiyan, Zeng Kui, and Sun Qili. 95 When the supply and demand parties have disputes over quality, they can be resolved through negotiation between the two parties, or the legal inspection agency can conduct arbitration analysis according to the inspection methods specified in this standard.
6 Marking, packaging, transportation and purchase and storage
6.1 The marking and packaging of chlorotoluron wettable powder shall comply with the relevant provisions of GB3769. 6.2 Chlorotoluron wettable powder is packaged in sealed plastic film bags, the net weight of each bag shall not exceed 500g, and a certain number of small bags shall be closely arranged in a box, and the net weight of each box shall not exceed 25kg (other forms of packaging may also be used according to user requirements). 6.3 During storage and transportation, it should be strictly prevented from moisture and sunlight, and good ventilation should be maintained; it should not be mixed with food, seeds and feed, and avoid contact with the skin and prevent inhalation through the mouth and nose.
Additional remarks:
This standard is proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the technical jurisdiction of the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. This standard is drafted by the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry and the Pesticide Inspection Institute of the Ministry of Agriculture. The main drafters of this standard are Jia Lijun, Ma Yaguang, Zhang Baizhen, Wang Yiyan, Zeng Kui and Sun Qili.5 When the supply and demand parties have disputes over quality, they can be resolved through negotiation between the two parties, or the legal inspection agency can conduct arbitration analysis according to the inspection methods specified in this standard.
6 Marking, packaging, transportation and purchase and storage
6.1 The marking and packaging of chlorotoluron wettable powder shall comply with the relevant provisions of GB3769. 6.2 Chlorotoluron wettable powder is packaged in sealed plastic film bags, the net weight of each bag shall not exceed 500g, and a certain number of small bags shall be closely arranged in a box, and the net weight of each box shall not exceed 25kg (other forms of packaging may also be used according to user requirements). 6.3 During storage and transportation, it should be strictly prevented from moisture and sunlight, and good ventilation should be maintained; it should not be mixed with food, seeds and feed, and avoid contact with the skin and prevent inhalation through the mouth and nose.
Additional remarks:
This standard is proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the technical jurisdiction of the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. This standard is drafted by the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry and the Pesticide Inspection Institute of the Ministry of Agriculture. The main drafters of this standard are Jia Lijun, Ma Yaguang, Zhang Baizhen, Wang Yiyan, Zeng Kui and Sun Qili.
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