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Chemical Industry Standard of the People's Republic of China
HG2462.1—93
Methyl thiophanate technical
1993—07—05 Issued
Ministry of Chemical Industry of the People's Republic of China
1994—01—01 Implementation
Chemical Industry Standard of the People's Republic of China
Methyl thiophanate technical
Subject Content and Scope of Application
HG2462.1—93
This standard specifies the technical requirements, test methods, inspection rules, and marking, packaging, transportation and storage requirements for methyl thiophanate technical. This standard applies to methyl thiophanate technical. Active ingredient: methyl thiophanate
Chemical name: 1,2-bis-(3-methoxycarbonyl-2-thioureido)benzeneStructural formula:
Molecular formula: C12H1N,OS2
Relative molecular mass: 342.40 (1989 international relative atomic mass). 2 Reference standards
GB1605
5 Sampling methods for commercial pesticides
GB3796 General rules for pesticide packaging
3 Technical requirements
3.1 Appearance: Yellow or gray powder, no visible foreign matter. 3.2 The technical material of methyl thiophanate shall also meet the following index requirements: Item
Methyl thiophanate content, %
Heating loss, %
4 Test method
Superior quality
4.1 Determination of methyl thiophanate content
Unless otherwise specified, all reagents used in this test are analytically pure reagents. 4.1.1 High performance liquid chromatography (arbitration method) 4.1.1.1 Summary of method
Qualified quality
The sample is dissolved in methanol, 4-hydroxybenzoic acid propyl ester is used as the internal standard, methanol + decahydrate (53+47) is used as the mobile phase, and the separation is carried out on a liquid chromatography column filled with Spherisorb C8 (30/127) 10um, and the components are detected by a UV detector with a wavelength of 269nm. 4.1.1.2 Reagents and solutions
Approved by the Ministry of Chemical Industry of the People's Republic of China on July 5, 1993 and implemented on January 1, 1994
Methanol (GB683);
Water: freshly made double distilled water;
HG2462.1-93
Mobile phase: methanol + water (53 + 47) (V+V), filtered through a G5 glass sand core filter funnel into a dark bottle, sealed and stored at low temperature. 4-Hydroxybenzoic acid propyl ester: no interferences were found after liquid chromatography analysis; Internal standard solution: 2g/L 4-hydroxybenzoic acid propyl ester methanol solution; Methyl thiophanate standard sample: known content, ≥98.5% (m/m). 4.1.1.3 Instruments
High performance liquid chromatograph: with variable wavelength UV detector; Chromatographic column: 4.6mm inner diameter, 200mm long stainless steel column, filled with Spherisorb C8 (30/127) 10um, theoretical plate number greater than 30,000,
Filter: filter membrane pore size about 0.5um;
Injector: 50uL.
4.1.1.4 Operation steps
4.1.1.4.1 Chromatographic operation conditions
Column temperature: 40℃;
Mobile phase flow rate: 1.5mL/min;
Detector wavelength: 269nm;
Injection volume: 10uL;
Retention time:
Methyl thiophanate 3.0min;
4-hydroxybenzoic acid propyl ester 5.7min.
The above HPLC conditions are typical operating parameters. According to the characteristics of the instrument, the operating parameters can be adjusted appropriately to obtain the best effect. HPLC chromatogram of methyl thiophanate technical drug 1-methyl thiophanate; 2-4-hydroxybenzoic acid propyl ester 4.1.1.4.2 Preparation of standard solution and sample solution Weigh the standard and sample containing 0.10g methyl thiophanate to an accuracy of 0.0001g, place them in 50mL volumetric flasks, dissolve them with methanol, dilute to the scale, and shake well. Use a pipette to transfer 5.0mL of the above solution into a 10mL stoppered vial, and then use a pipette to transfer 5.0mL of the internal standard solution into each of the above vials, shake well, and filter with a 0.5um pore size filter. Take 0.5mL of the filtrate into a 10mL stoppered vial, dilute to 10mL with mobile phase, and shake well.
4.1.1.4.3 Determination
HG2462.1—93
Under the selected chromatographic conditions, after the instrument is stable, repeat the injection of the standard solution until the relative deviation of the peak area ratio of methyl thiophanate and 4-hydroxybenzoic acid propyl ester between two consecutive injections is less than 0.5%. Then inject in the following order: a. Standard solution; b. Sample solution; c. Sample solution; d. Standard solution. 4.1.1.5 Calculation
According to the chromatograms of the four injections a, b, c, and d, calculate the peak areas of methyl thiophanate and 4-hydroxybenzoic acid propyl ester ad and bc respectively. The mass percentage of methyl thiophanate (X1) is calculated according to formula (1): Tmw
Wherein: -- the average value of the peak area ratio of methyl thiophanate to 4-hydroxybenzoic acid propyl ester in the sample solution injected twice in b and c; T2-the average value of the peak area ratio of methyl thiophanate to 4-hydroxybenzoic acid propyl ester in the standard solution injected twice in a and d; m1-mass of the sample, ;
m2-mass of the standard sample, g;
w-purity of the standard sample, %, m/m).
4.1.1.6 Allowable difference
The absolute difference between the results of two parallel determinations shall not exceed 1.5%. 4.1.2 Thin layer-ultraviolet method
4.1.2.1 Summary of the method
The sample is first subjected to thin layer separation to remove impurities, and then measured by ultraviolet spectrophotometry at a wavelength of 269nm. 4.1.2.2 Reagents and solutions
Ethyl acetate (HG3-1226);
n-hexane;
Acetone (GB686);
Methanol (GB683);
Silica gel GF254 (for thin layer chromatography): particle size 10~40um; Methyl thiophanate standard sample: known content, ≥98.5% (m/m); Developing solvent: ethyl acetate + n-hexane = 1+1 (V+V), mix well. 4.1.2.3 Instruments
UV spectrophotometer;
Chromatography cylinder;
Thin layer plate: Weigh about 8g of silica gel GF254, put it in a glass mortar, add 20mL of water, grind it to a homogeneous paste, and immediately pour it on a clean 150×180×3mm glass plate, gently vibrate to evenly distribute the silica gel on the plate, and place it horizontally to dry. Before use, place the thin layer plate in a 110℃ oven for activation for 1.0h, take it out, and place it in a desiccator for later use. UV lamp: wavelength range includes 254nm;
Volume flask: 50mL;
Pipette: 1mL;
Glass frit filter funnel: G4, 25mL.
4.1.2.4 Operation steps
Weigh the standard sample and sample containing 0.13g of methyl thiophanate, accurate to 0.0001g. Place them in a G4 glass frit funnel respectively, dissolve them with acetone, filter them into a 50mL volumetric flask, make up to volume, and shake them well. Pipette 1.0mL of the solution onto the thin layer plate, 2cm from the bottom and 1cm on both sides, and spot them in a straight line along the 15cm side, and use a small amount of acetone to wash the residue on the tip of the pipette on the spotting line. After the solvent evaporates, place the thin layer plate in a chromatography cylinder saturated with a developing agent, with a developing agent depth of 1 cm in the chromatography cylinder. When the developing agent front rises to 14 cm from the origin, take out the plate, and after the solvent evaporates, draw the main spectrum band at Rf-0.35 under a UV lamp. Quantitatively transfer the main spectrum band to a G4 glass sand core filter funnel lined with double-layer quantitative filter paper. Wash the silica gel in the funnel with 45 mL of methanol in batches. Collect the filtrate in a 50 mL volumetric flask, dilute with methanol, and shake well. Transfer 10 mL to a 50 mL volumetric flask, dilute with methanol, and shake well. At the same time, make a blank measurement. At a wavelength of 269 nm, use the blank solution as a reference and use a 1 cm absorption cell to simultaneously measure the absorbance of the standard and sample solutions. 4.1.2.5 CalculationbZxz.net
The mass percentage of methyl thiophanate (X1) is calculated according to formula (2): AimzD
Wherein: A, — absorbance of methyl thiophanate in the sample solution; A2 — absorbance of methyl thiophanate in the standard solution. 4.1.2.6 Allowable difference
The absolute difference between the results of two parallel determinations should not be greater than 1.5%. 4.2 Determination of heating loss
4.2.1. Instrument
Weighing bottle: inner diameter 50mm, height 30mm;
Oven: 100±2℃;
Dryer.
4.2.2 Place the weighing bottle in an oven at 100±2℃ for 1.0h, put it in a dryer to room temperature, weigh it to an accuracy of 0.0001g. Put 2.5g of the sample in the bottle, flatten it, and weigh it again to an accuracy of 0.0001g. Put the weighing bottle back into the oven without covering it, and after drying for 2.0h, cover it, take it out, put it in a dryer to room temperature, and weigh it to an accuracy of 0.0001g. 4.2.3 Calculation
The heating loss (X2) expressed as a mass percentage is calculated according to formula (3): X2-
Where, ms—the mass of the sample and weighing bottle before drying, g; m4—the mass of the sample and weighing bottle after drying, g; ms——the mass of the weighing bottle, g.
5 Inspection rules
5.1 The technical drug of methyl thiophanate shall be inspected by the quality supervision and inspection department of the production unit. The production unit shall ensure that all technical drugs of methyl thiophanate leaving the factory meet the requirements of this standard. 5.2 The business unit and the user unit have the right to verify whether the received methyl thiophanate technical drug meets the requirements of this standard in accordance with the provisions of this standard.
5.3 The sampling method shall be carried out in accordance with GB1605. The sample shall be divided into two bottles, one bottle shall be submitted to the quality supervision and inspection department for inspection, and the other bottle shall be sealed. 5.4 In the test results, when there are indicators that do not meet the requirements of this standard, samples shall be taken from twice the amount of packaging for re-inspection. In the results of the re-inspection, even if one indicator does not meet the requirements of this standard, the entire batch of methyl thiophanate technical drug is an unqualified product. 5.5 When the supply and demand parties have disputes over product quality, they can be resolved through negotiation between the two parties or by the statutory inspection agency, in accordance with the inspection methods specified in this standard, to conduct arbitration analysis. 6 Marking, packaging, transportation and purchase and storage
6.1 The marking and packaging of methyl thiophanate technical drug shall comply with the relevant provisions of GB3796 and be trademarked. 6.2 During transportation and storage, it should be strictly protected from moisture and sunlight, and maintained in good ventilation. It should not be mixed with food, seeds, and feed, and should avoid contact with the skin and inhalation through the mouth and nose.
A1 Method Summary
HG2462.1-93
Appendix A
CIPAC Method (reference)
The sample was dissolved in methanol, 4-hydroxybenzoic acid propyl ester was used as the internal standard, ethyl + methanol + water (25+25+50) was used as the mobile phase, and the separation was carried out on a liquid chromatography column filled with Lichrosorb RP-8 (10um) or Zorbox BPC8 (7~8um), and the components were detected with a UV detector at a wavelength of 269nm.
Instruments and reagents
Liquid chromatograph with variable wavelength UV detector; Chromatographic column: stainless steel column with inner diameter of 4.6mm and length of 250mm, filled with Lichrosorb RP-8 (10um) or Zorbox BPC8 (7-8um), theoretical plate number of more than 5,000;
Filter: with 0.45um filter element;
Ultrasonic bath;
Acetonitrile: HPLC grade;
Methanol: HPLC grade;
Water: distilled water or deionized water,
Mobile phase: acetonitrile + methanol + water (25+25+50), filtered and degassed with a 0.45um filter before use. Methyl thiophanate standard: analytical standard with known purity; 4-hydroxybenzoic acid propyl ester: high grade;
Internal standard solution: 0.5g 4-hydroxybenzoic acid propyl ester methanol solution. Chromatographic operating conditions
Column temperature: 40℃;
Mobile phase flow rate: 1mL/min (about 4MPa);Detector wavelength: 269nm;
Detection sensitivity: make the peak reach 80% to 90% of the full scaleInjection volume: 20uL;
Recording instrument paper speed: 0.5cm/min.
Retention time:
Methyl thiophanate: 6.7min;
4-hydroxybenzoic acid propyl ester: 10.4min.
Preparation of A4 standard solution and sample solution
Weigh the standard and sample containing 0.10g of methyl thiophanate into a 200mL volumetric flask, add 150mL of methanol, place in an ultrasonic bath for 10min, cool and dilute to volume with methanol, and shake well. Transfer 5mL of the upper clear liquid into a 50mL volumetric flask, accurately transfer 5mL of the internal standard solution, adjust the volume with the mobile phase, and shake well. Before injection, filter with a filter with a 0.45um filter element. The standard sample must be prepared daily. A5
Determination steps
Under the specified chromatographic conditions, after the instrument is stable, repeatedly inject the standard solution until the relative deviation of the peak area (or peak height) ratio of methyl thiophanate and 4-hydroxybenzoic acid propyl ester in two consecutive injections is less than 0.5%. Then inject in the following order: a. Standard solution; b. Sample solution, c. Sample solution; d. Standard solution. A6
According to the chromatograms of the four injections a, b, c, and d, calculate the peak areas (or peak heights) of methyl thiophanate and 4-hydroxybenzoic acid propyl ester a, d and b, c respectively.
The mass percentage of methyl thiophanate (X,) is calculated according to formula (A1): Timzu
Wherein: Yuanπ——the average value of the peak area (or peak height) ratio of methyl thiophanate to 4-hydroxybenzoic acid propyl ester in the sample solutions of b and c; T2——the average value of the peak area (or peak height) ratio of methyl thiophanate to 4-hydroxybenzoic acid propyl ester in the standard solution of a and d; m1——the mass of the sample, g;
m2the mass of the standard sample,,
w——the purity of the standard sample, (%, m/m). Additional remarks:
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 was drafted by the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Wu Qi, Xu Laiwei, Xing Hong, Liu Guoxiu, Gu Shaolin, Han Guangyan, and Wang Tongling. 645um filter element;
ultrasonic bath;
acetonitrile: HPLC grade;
methanol: HPLC grade;
water: distilled water or deionized water,
mobile phase: acetonitrile + methanol + water (25+25+50), filtered and degassed with a 0.45um filter before use. Methyl thiophanate standard: analytical standard with known purity; 4-hydroxybenzoic acid propyl ester: high grade;
internal standard solution: 0.5g 4-hydroxybenzoic acid propyl ester methanol solution. Chromatographic operating conditions
Column temperature: 40℃;
Mobile phase flow rate: 1mL/min (about 4MPa);Detector wavelength: 269nm;
Detection sensitivity: make the peak reach 80% to 90% of the full scaleInjection volume: 20uL;
Recording instrument paper speed: 0.5cm/min.
Retention time:
Methyl thiophanate: 6.7min;
4-hydroxybenzoic acid propyl ester: 10.4min.
Preparation of A4 standard solution and sample solution
Weigh the standard and sample containing 0.10g of methyl thiophanate into a 200mL volumetric flask, add 150mL of methanol, place in an ultrasonic bath for 10min, cool and dilute to volume with methanol, and shake well. Transfer 5mL of the upper clear liquid into a 50mL volumetric flask, accurately transfer 5mL of the internal standard solution, adjust the volume with the mobile phase, and shake well. Before injection, filter with a filter with a 0.45um filter element. The standard sample must be prepared daily. A5
Determination steps
Under the specified chromatographic conditions, after the instrument is stable, repeatedly inject the standard solution until the relative deviation of the peak area (or peak height) ratio of methyl thiophanate and 4-hydroxybenzoic acid propyl ester in two consecutive injections is less than 0.5%. Then inject in the following order: a. Standard solution; b. Sample solution, c. Sample solution; d. Standard solution. A6
According to the chromatograms of the four injections a, b, c, and d, calculate the peak areas (or peak heights) of methyl thiophanate and 4-hydroxybenzoic acid propyl ester a, d and b, c respectively.
The mass percentage of methyl thiophanate (X,) is calculated according to formula (A1): Timzu
Wherein: Yuanπ——the average value of the peak area (or peak height) ratio of methyl thiophanate to 4-hydroxybenzoic acid propyl ester in the sample solutions of b and c; T2——the average value of the peak area (or peak height) ratio of methyl thiophanate to 4-hydroxybenzoic acid propyl ester in the standard solution of a and d; m1——the mass of the sample, g;
m2the mass of the standard sample,,
w——the purity of the standard sample, (%, m/m). Additional remarks:
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 was drafted by the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Wu Qi, Xu Laiwei, Xing Hong, Liu Guoxiu, Gu Shaolin, Han Guangyan, and Wang Tongling. 645um filter element;
ultrasonic bath;
acetonitrile: HPLC grade;
methanol: HPLC grade;
water: distilled water or deionized water,
mobile phase: acetonitrile + methanol + water (25+25+50), filtered and degassed with a 0.45um filter before use. Methyl thiophanate standard: analytical standard with known purity; 4-hydroxybenzoic acid propyl ester: high grade;
internal standard solution: 0.5g 4-hydroxybenzoic acid propyl ester methanol solution. Chromatographic operating conditions
Column temperature: 40℃;
Mobile phase flow rate: 1mL/min (about 4MPa);Detector wavelength: 269nm;
Detection sensitivity: make the peak reach 80% to 90% of the full scaleInjection volume: 20uL;
Recording instrument paper speed: 0.5cm/min.
Retention time:
Methyl thiophanate: 6.7min;
4-hydroxybenzoic acid propyl ester: 10.4min.
Preparation of A4 standard solution and sample solution
Weigh the standard and sample containing 0.10g of methyl thiophanate into a 200mL volumetric flask, add 150mL of methanol, place in an ultrasonic bath for 10min, cool and dilute to volume with methanol, and shake well. Transfer 5mL of the upper clear liquid into a 50mL volumetric flask, accurately transfer 5mL of the internal standard solution, adjust the volume with the mobile phase, and shake well. Before injection, filter with a filter with a 0.45um filter element. The standard sample must be prepared daily. A5
Determination steps
Under the specified chromatographic conditions, after the instrument is stable, repeatedly inject the standard solution until the relative deviation of the peak area (or peak height) ratio of methyl thiophanate and 4-hydroxybenzoic acid propyl ester in two consecutive injections is less than 0.5%. Then inject in the following order: a. Standard solution; b. Sample solution, c. Sample solution; d. Standard solution. A6
According to the chromatograms of the four injections a, b, c, and d, calculate the peak areas (or peak heights) of methyl thiophanate and 4-hydroxybenzoic acid propyl ester a, d and b, c respectively.
The mass percentage of methyl thiophanate (X,) is calculated according to formula (A1): Timzu
Wherein: Yuanπ——the average value of the peak area (or peak height) ratio of methyl thiophanate to 4-hydroxybenzoic acid propyl ester in the sample solutions of b and c; T2——the average value of the peak area (or peak height) ratio of methyl thiophanate to 4-hydroxybenzoic acid propyl ester in the standard solution of a and d; m1——the mass of the sample, g;
m2the mass of the standard sample,,
w——the purity of the standard sample, (%, m/m). Additional remarks:
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 was drafted by the Shenyang Chemical Industry Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Wu Qi, Xu Laiwei, Xing Hong, Liu Guoxiu, Gu Shaolin, Han Guangyan, and Wang Tongling. 6
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