HG/T 3479-1977 Chemical reagent Phthalic anhydride (formerly HG/T 3-1107-77)
Some standard content:
Standard of the Ministry of Petrochemical Industry of the People's Republic of China
Chemical reagents
Phthalic anhydride
This reagent is a white needle-shaped crystal, soluble in hot water, hardly soluble in cold water, soluble in ethanol, ether and benzene. Indicative formula: CcH4(CO)20
Molecular weight: 148.12 (according to the international atomic weight of 1975) I. Technical conditions
1. The content of CsH (CO)20 is not less than
Analytical pure
Chemical pure
2. Melting point range (℃):
Analytical pure
HG3-1107-77bZxz.net
Replace HGB3377-60
.·129~133(1℃)|| tt||Chemical purity
3. Maximum impurity content (index in %): Name
(1) Ignition residue (in terms of sulfate)
(2) Chloride (CI)
(3) Sulfate (SO%)
(4) Heavy metal (in terms of Pb)
2. Inspection regulations
Sampling and acceptance shall be carried out in accordance with the provisions of GB619-77, then
3. Test method
-129~133(2℃).
The standard solution, impurity standard solution, preparation and product required for the determination shall be prepared in accordance with the provisions of GB601-77, GB602-77 and GB603-77. 1. Determination of C6H(CO)20 content: Weigh 1 gram of sample and weigh to 0.0002 grams. Dissolve in 100 ml hot water, add 2 drops of 1% phenolic indicator solution, and titrate with 0.5N sodium hydroxide standard solution until the solution turns pink. C.H4(CO)20 content% (x) is calculated as follows: X=V·CX0. 07406×100
Ministry of Petrochemical Industry of the People's Republic of China Tianjin
October 1, 1978
Tianjin Chemical Reagent Factory No. 1
W.bzsoso,comHG3-1107-77
Where: V—amount of sodium hydroxide standard solution, ml, C—equivalent concentration of sodium hydroxide standard solution, N, G——sample weight, g,
0.07406——grams of C6H4(CO)2O per milliequivalent. 2. Melting point determination: Determine according to the provisions of GB617-77. 3. Determination of impurities: The sample must be weighed to 0.01 g. (1) Ignition residue: Weigh 4 g of sample, place in a constant weight, heat to carbonize, cool, add 1 ml of sulfuric acid, heat until sulfuric acid vapor is completely exhausted, ignite at 800°C to constant weight, the weight of the residue shall not be greater than: analytically pure
chemically pure ·
1.0 mg,
…2.0 mg.
(2) Chloride: Weigh 0.5 g of sample, dissolve in 15 ml of ethanol and 15 ml of water, add 2 ml of 5N nitric acid and 1 ml of 0.1N silver nitrate, shake well, let stand for 10 minutes, the turbidity shall not be greater than the standard. The standard is the following amounts of CI:
analytical pure ·
chemically pure
and treat it in the same way as the sample.
0.025 mg;
0.050 mg.
(3) Sulfate: Weigh 1.5 g of sample, place in evaporator III, add 10 ml of water, 3 ml of 1% sodium carbonate solution, evaporate to dryness on a water bath, heat until the sample is completely evaporated, add 3 ml of saturated bromine water, evaporate to dryness. Add 2 ml of 6N hydrochloric acid and evaporate to dryness. Dissolve the residue in 10 ml of water, filter, wash the residue with water, and dilute to 25 ml. Add 1 ml of 3N hydrochloric acid, keep warm in a water bath at 30~35℃ for 10 minutes, add 3 ml of 25% barium chloride solution, shake the hook, and leave for 30 minutes. The turbidity should not be greater than the standard. The standard is to take 3 ml of 1% sodium carbonate, 2 ml of 6N hydrochloric acid and the following amounts of SO4: analytical pure
chemical pure·
dilute to 25 ml, and treat the filtered sample solution in the same way. 0.015 mg,
·0.075 mg.
(4) Heavy metals: Weigh 1 gram of sample, dissolve in 10 ml of ethanol at warm temperature, add 30 ml of water, neutralize with 10% sodium hydroxide solution (about 2 ml), and add 2 ml excess, 1 ml of 10% potassium sodium tartrate solution and 2 ml of 2% thioacetamide solution, and keep warm in a 60°C water bath for 10 minutes. The dark color should not be darker than the standard. The standard is to take the following amount of Pb:
Analytical pure
Chemical pure
Dilute to the same volume as the neutralized test solution, and treat it in the same way as the sample solution. IV. Packaging and marking
1. Packaging: in accordance with the provisions of HG3-11964. Inner packaging form: G-2;
Outer packaging form: I-1;
Packing unit: Class 4 and 5.
2. Marking: in accordance with the provisions of HG3-11964. 2
0.01 mg,
0.05 mg.
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