GB/T 5533-1985 Vegetable oils and fats - Determination of soap content

This standard is applicable to the determination of soap content in commercial vegetable oils and fats. GB/T 5533-1985 Testing of vegetable oils and fats Determination of soap content GB/T5533-1985 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Inspection of vegetable oilsMethodsfordetermination of saponified matter contentThis standard applies to the determination of soap content in commercial vegetable oils. GB/T 5533-85
The soap content in oils, that is, the amount of saponified matter remaining in the oils after alkali refining (in terms of sodium oleate). Instruments and appliances
1.1 Conical flask: 250ml;
1.2 Measuring cylinder;
1.3 Microburette;
1.4 Constant temperature water bath;
1.5 Electric furnace;
1.8 Beaker, reagent bottle, etc.;
1.7 Analytical balance: sensitivity 0.0001g;
1.8 Balance: sensitivity 0.01g.
2 Reagents
2.1 Petroleum ether: boiling point 60~90℃;
2.2 95% neutral ethanol;
2.3 0.2% methyl red ethanol solution;
2.4 0.02N sulfuric acid solution;
2.5 Anhydrous sodium carbonate. www.bzxz.net
3 Operation method
Weigh about 10g (W) of the mixed sample, inject it into a dry conical flask, add 10ml of ethanol and 60ml of petroleum ether, shake to dissolve the sample, slowly add 80ml of 80℃ distilled water, shake to make it emulsified, drop 3 drops of methyl red indicator, add 0.02N sulfuric acid solution drop by drop while hot, shake once after each drop, and drop until the solution under the layer shows a slightly reddish color. 4
Result calculation
The soap content of oil is calculated according to the following formula:
V × N × 0.304
Soap content (%)=
Wherein: V is the volume of sulfuric acid solution used for titration, ml; N
The equivalent concentration of sulfuric acid solution;
w is the weight of the sample, g;
0.304 is the number of grams of sodium oleate equivalent to each gram of equivalent sulfuric acid. ×100
The allowable difference between the two test results shall not exceed 0.02%. The average is the test result. The test result is rounded to the second decimal place.
Additional remarks:
This standard is proposed by the Ministry of Commerce of the People's Republic of China. This standard is drafted by the Grain Storage and Transportation Bureau of the Ministry of Commerce. The main drafters of this standard are Gao Xiuwu, Yang Haoran, Wu Yanxia and Lv Guifen. Issued by the National Bureau of Standards on November 2, 1985
Implemented on July 1, 1986
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