Detection method for Ca2+:
Experimental instruments and reagents: beakers; Conical flask; Funnel; Burette; Electric furnace; Anhydrous ethanol; Hydrochloric acid, NH3-NH4Cl buffer solution, calcium indicator, 0.02mol/LEDTA standard solution.
Test steps:
1. Accurately weigh a certain amount of ACR processing aid sample (accurate to 0.0001g) and place it in a beaker. Wet it with anhydrous ethanol, then add an excess of 1:1 hydrochloric acid and heat it on an electric furnace to allow calcium ions to fully react with hydrochloric acid;
2. Wash with water and filter with a funnel to obtain its clear liquid;
3. Adjust the pH value to be greater than 12 using NH3-NH4Cl buffer solution, add an appropriate amount of calcium indicator, and titrate with 0.02mol/LEDTA standard solution. The endpoint is when the color changes from purple red to pure blue;
4. Conduct a blank test simultaneously;
5. Calculate C # a2+=0.02 $(V-V0) $0.04004M $%&&
V – Volume of EDTA solution consumed when testing ACR processing aid samples (mL).
V # – Volume of solution consumed during blank test
M — Weigh the mass of ACR processing aid sample (g).
Burning method for measuring inorganic substances:
Experimental instruments: analytical balance, muffle furnace.
Test steps: Take 0.5,1.0g ACR processing aid samples (accurate to 0.001g), place them in a 950 constant temperature muffle furnace and burn for 1 hour, then cool and weigh to calculate the remaining burned material. If inorganic substances are added to the sample of ACR processing aids, there will be more residue.
Solvent method:
1. Experimental instruments and reagent analysis balance; 25mL volumetric flask; Trichloromethane.
Step 2: According to the ACR intrinsic viscosity testing method, weigh 75mg of the sample and place it in a 25mL volumetric flask. Add trichloromethane solvent. If there is turbidity or visible light
Post time: May-27-2024
