GB/T 9104.7-1988 Test method for industrial stearic acid Determination of inorganic acid GB/T9104.7-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test methods for industrial stearic acids-Determination of inorganic acidwww.bzxz.net
Test methods for industrial stearic acids-Determination of inorganic acid Subject content and scope of application
This standard specifies the determination method of inorganic in industrial stearic acid. UDC 668. 1. 012
：543.06
GB 9104.7--88
This standard applies to the determination of inorganic in industrial stearic acid produced by pressing or distillation after hydrolysis of animal and vegetable fats. 2 Reagents
2.1 Sulfuric acid (GB625) 0.001% standard solution. Take 75mL of sulfuric acid with a density of 1.84g/mL, pour it into a small amount of distilled water, and then dilute to 100mL Lc (HzSO.) ~～0.125mol/L). Use the standard reagent anhydrous sodium carbonate (GB1255) to calibrate its concentration. Calculate the number of milliliters of sulfuric acid solution required for the calibrated sulfuric acid according to 1/c(HzSO,)×0.98. Measure the calculated volume of sulfuric acid solution, inject it into a 250mL volumetric flask, dilute it to the scale with distilled water, shake it thoroughly, then draw 25mL, inject it into a 1000mL volumetric flask, dilute it to the scale with distilled water, and mix it to obtain a 0.001% sulfuric acid standard solution. 2.2 Methyl orange indicator (HGB3089): 0.1% aqueous solution. 3 Instruments
Test tube (glass must be colorless) 5mL.
4 Test procedure
Weigh 5g of the sample, place it in a clean and dry 50mL beaker, and heat it to melt it. Add 5mL of boiled distilled water to the measuring tube, heat and stir for 2 minutes, and cool to solidify the stearic acid. Take out the fatty acid block, pour the solution into a test tube, add a drop of methyl orange indicator, and add an equal volume of 0.001% sulfuric acid standard solution and an equal amount of indicator in another test tube. 5. Processing of results
Visually compare the colors of the two. If the color of the sample solution is not darker than that of the sulfuric acid standard solution, it is considered that the inorganic acid is less than 0.001%. Additional notes:
This standard was proposed by the Ministry of Light Industry of the People's Republic of China. This standard is under the technical jurisdiction of the Daily Chemical Industry Scientific Research Institute of the Ministry of Light Industry. This standard was drafted by the Daily Chemical Industry Scientific Research Institute of the Ministry of Light Industry. Approved by the Ministry of Light Industry of the People's Republic of China on April 30, 1988114
Implementation on October 1, 1988
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