Some standard content:
People's Republic of China
Standard
Country
Dichlorvos Crude Oil
GB2548——81
(Confirmed in 1988)
This standard applies to Dichlorfon (O,O-dimethyl-O-2,2-dichlorovinyl phosphate) crude oil produced by alkaline hydrolysis of trichlorfon, structural formula:
Molecular formula: C,H,O,C1 ,P
CH,o
CH,o
Molecular weight: 220.99 (according to the 1979 international atomic weight) Technical conditions
1, Appearance; Light yellow to yellow-brown transparent Liquid, 2. Dichlorvos crude oil should meet the following requirements, refer to
ref|
label
name
grade
O,0 -Dimethyl-0-2,2-dichlorovinyl phosphate content, trichlorfon content,
acidity (calculated as H, SO,),
moisture content, ||tt ||%
%
%
2. Acceptance rules
95.0
2.5
0.20
0.05|| tt||product
standard
grade
92.0
2.5wwW.bzxz.Net
0.20
product
0.05||tt| |3. Dichlorvos crude oil shall be inspected by the quality inspection department of the production plant in accordance with this standard. The production plant shall ensure that all dichlorvos crude oil leaving the factory meets the requirements of this standard.
4. Each batch of dichlorvos crude oil leaving the factory should be accompanied by a quality certificate, which includes: name of the manufacturer, product name, production date, batch number, net weight, standard number and instructions for use, indicating the minimum packaging, and annotating it in accordance with the provisions of GB190-73 "Toxic" mark. 5. The quantity of each batch of dichlorvos crude oil shall not exceed the capacity of the storage tank before packaging. 6 The user has the right to verify the quality of the received dichlorvos crude oil in accordance with the provisions of this standard. Verify whether its indicators are Comply with the requirements of this standard.
7. If one indicator in the test result does not meet the requirements of this standard, double sampling should be re-tested to measure the new test results, even if only one indicator does not meet the requirements of this standard. , the entire batch of dichlorvos crude oil cannot be accepted. 8. Sampling method: After the product is mixed evenly, use a method that avoids contact with water vapor, and take a sample of the required weight or volume. The sampling amount should not be less than 0.5%. When taking samples, the factory name, product name, batch number, production date, sampling date and location must be indicated. National
standard
issued by the General Administration
People's Republic of China. The Ministry of Chemical Industry proposed to implement on March 1, 1982
Drafted by Tianjin Pesticide Factory
GB2649-81
9. When the supply and demand parties have disputes over product quality, they can negotiate through relevant units , conduct arbitration analysis in accordance with the inspection methods specified in this standard
3. Inspection methods
10.O,0-dimethyl-0-2,2-dichlorovinyl phosphate content. Determination (1) Instrument
Gas Chromatograph
Identifier: Thermal conductivity cell:
Column tube, stainless steel column 4.0×2000 mm: Stationary phase: Silicone oil DC550: Shanghai Reagent Factory 101 White support (Aqua Regia treatment) 60~80 mesh = 10:100; carrier gas, hydrogen.
Note, support treatment method
(2) Reagent
biphenyl, chromatographically pure ;
Toluene, analytical grade
(3) Operating conditions
Boil with aqua regia at 80°C for 16 to 24 hours, wash, dry, sieve, and set aside. . Column temperature, 174℃ (actual temperature);
detection temperature, 180℃ (actual temperature); vaporization temperature: about 200℃ (actual temperature); bridge flow, 200 mA:
air flow Speed, 120 ml/min;
Paper speed: 10 mm/min;
Attenuation, 1.
(4) Determination method: Internal standard method, calculated based on peak height. Standard substance: joint lift;
Weighing volume: 0.19~0.20 g of dichlorvos crude oil (accurate to 0.0002 g) Solvent: 1.0.ml of toluene (accurate to 0.1 ml): Injection volume: 4.0 μl || tt||Standard curve drawing: weigh 0.16~0.19 grams of biphenyl (accurate to 0.0002 grams), and then weigh dichlorvos according to the series of biphenyl: dichlorvos equal to 1:1.5, 1:1.3, 1:1.1...1:0.5 respectively Standard sample. Add 1.0 ml of toluene, stir to mix, inject 4.0 μl of each sample, prepare a chromatogram, and calculate the height ratio of dichlorvos and biphenyl. With the peak height ratio as the horizontal axis and the weight ratio as the vertical axis, draw a standard curve or use the least squares method to find the corresponding slope and intercept. Note: According to the stability of the instrument and the degree of change of the standard sample, the standard curve should be calibrated frequently to ensure the accuracy of the measurement results. Sample measurement: Accurately weigh 0.16 to 0.19 grams of biphenyl (accurate to 0.0002 grams) and 0.19 to 0.20 grams of dichlorvos crude oil, add 1.0 liter of toluene, shake and mix, inject 4.0 microliters of sample, and prepare a chromatogram. Find the peak height ratio of dichlorvos and biphenyl. The dichlorvos content % (X,) in crude oil can be found by checking the standard curve method, or calculated by the following formula: X(ah./h+b)W+×100||tt ||W
Where: a The slope of the standard curve:
b
The intercept of the standard curve:
h,——The peak height of dichlorvos, mm ;
h,-——peak height of internal standard substance, mm;
W,——weight of internal standard substance, grams
W——weight of sample, grams.
GB2549-81
Note: The maximum allowable deviation of parallel measurement results shall not be greater than 1.0%. 11. Determination of trichlorfon content in dichlorvos crude oil (1) Reagents and solutions
Methanol (GB683-79): analytical grade.
Anhydrous sodium carbonate (GB639--77): chemically pure, 1.0M solution; Nitric acid (GB626-78): chemically pure, 1:3 solution; Silver nitrate (GB670-77): analytically pure, 0.05 N standard solution; ammonium thiocyanate (GB660-78): analytical grade, 0.05N standard solution; ferric ammonium sulfate (GB1279-77): analytical grade, 10% solution, nitrobenzene (HG3-963-76): analytical pure. (2) Measurement procedures
Weigh 6 to 8 grams of sample (accurate to 0.0002 grams), place it in a 250 ml Erlenmeyer flask, add 40 ml of methanol, and after the sample is dissolved, place the Erlenmeyer flask Place in a constant temperature water bath and maintain 30±0.5℃. After 10 minutes, add 5 ml of 1.0M sodium carbonate solution and shake once a minute. After another 10 minutes, add 5 ml of 1:3 nitric acid solution to make the solution acidic. Add 50 ml of distilled water, take out the Erlenmeyer flask from the constant temperature water bath, and accurately add 10 ml of 0.05N silver nitrate standard solution, 3 ml of 10% ferric ammonium sulfate solution, and 5 ml of nitrobenzene. Shake the Erlenmeyer flask fully to completely condense the silver fluoride precipitate, and back-drop the test solution with 0.05N ammonium thiocyanate standard solution until it turns into a more stable light red color. Blank measurement: Weigh 6 to 8 grams of sample (weigh accurately to 0.0002 grams), place it in a 250 ml Erlenmeyer flask, add 40 ml of methanol, and after the sample is dissolved, add 7 ml of 1:3 nitric acid solution, and slowly Add 5 ml of 1.0M sodium carbonate solution and place the Erlenmeyer flask in a constant temperature water bath to maintain 30±0.5°C. After 10 minutes, take out the Erlenmeyer flask, add 50 ml of distilled water, and then accurately add 10 ml of 0.05N silver nitrate solution, 3 liters of 10% ferric ammonium sulfate solution and 5 ml of nitrobenzene. Then shake it thoroughly to completely condense the silver fluoride precipitate, and back-tit the solution with 0.05N ammonium thiocyanate solution until it turns into a more stable light red color. Trichlorfon content % (X.) in dichlorvos crude oil is calculated according to the formula: (N.vi-nV,- N.ve-nev4) ×100Xg=0.2575×1.01×(
where: N,-
Normal concentration of silver nitrate solution:
G.
V, - the volume of silver nitrate solution added to the test solution, ml: N, equivalent of ammonium thiocyanate solution Concentration;
V.—the volume of ammonium thiocyanate solution used when back-dropping the silver nitrate solution, ml; Va
V.
—the silver nitrate solution added in the blank measurement Volume, milliliters; G2
-The volume of ammonium thiocyanate solution used when back-dropping the silver nitrate solution in the blank measurement, side liters: G, weight of the sample, grams;
Weight of sample in blank measurement, grams: G
0.2575-
1.01-
Grams of trichlorfon per milliequivalent:
Correction coefficient,
12. Determination of acidity
(1) Reagents and solutions ||tt| |Sodium hydroxide (GB629-81): analytical grade, 0.05N standard solution; methyl red indicator: 0.1% solution
(2) Determination procedure
Weigh the dichlorvos crude oil sample 0.48~ 0.53 g (weigh accurately to 0.0002 g), place it in a 300 ml bottle, add 1 drop of the emulsifier used to mix dichlorvos emulsifiable concentrate and 50 ml of distilled water (pre-cooled to 0~1°C), shake to dissolve the sample, and add drops Add 5~6GB2549-81
drops of methyl red indicator solution, and then put the Erlenmeyer flask into an ice bath. When the temperature of the test solution drops to 0~1°C, titrate the free acid in it with 0.05N sodium hydroxide standard solution until it turns orange as the end point.
Acidity % (X,) is calculated according to the following formula:
X,-NVtx0.049 ×100
G
Where, N, sodium hydroxide standard solution The normal concentration; V, - the volume of sodium hydroxide standard solution used to titrate the free acid, side liter: G - the weight of the sample, grams,
0.049 - the number of grams of sulfuric acid per milliequivalent. 13. Determination of moisture content
According to GB1600-79 "Pesticide Moisture Determination Method", 4. Packaging, marking, storage and transportation
14. Dichlorvos crude oil is prohibited from being packaged in ordinary iron sheets and should be packed in In the appropriate sanitary container specified at the time of ordering. 15. A quality certificate should be included with each batch of packaged finished product. The content of the certificate includes: name of the manufacturer, product name, batch number, date of manufacture, net weight, proof that the product quality complies with this standard, and this standard number. 16. Each unit packaging container should be marked with: manufacturer name, product name, batch number, production date, net weight and this standard number. And mark "poisonous" according to the regulations of GB190-73. 17. During transportation, they must be strictly protected from moisture and sunlight, and good ventilation must be ensured. They must not be mixed with food, seeds, or feeds, avoid contact with skin, and prevent inhalation through mouth.
Note: From the date of implementation of this standard, the original standard HG2-296-65 is invalid.
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