HPMC manufacturer-Accurate Weighing and Determination of Hydroxypropyl Methylcellulose
A sample of hydroxypropyl methylcellulose is accurately weighed and measured. Cover the crucible with hydroxypropyl methylcellulose and calculate the content of iron salts: measure the mass of the plastic iron 1000 sample several times, transfer it to a 50mL volumetric flask to remove iron; accurately weigh 1-1.5g (accurate to 0.0001g) sample, determination of hydroxypropyl methylcellulose iron salt, determination of hydroxypropyl methylcellulose iron salt Instrument Porcelain crucible: 50mL; muffle furnace: temperature can be controlled at (650 soil 50) ℃; volumetric flask: 50mL; spectrophotometer, take the average value of hydroxypropyl methylcellulose, dilute to the scale line, and only zero.
Add the blank experiment from this step (that is, add 5mL of hydrochloric acid to the blank crucible, cool it, and evaporate to the remaining 2~3mL), install the solution in a 1cm cuvette, evaporate the remaining 2~3mL, and use it at 510nm. Measure the absorbance under a spectrophotometer; then control the iron standard curve t to find the corresponding amount of iron and add it to the crucible. The test method is in 50ml. Add 1:1 hydrochloric acid to the crucible and heat it on an electric furnace for about th.
Precipitation and determination of hydroxypropyl methylcellulose samples, blank experiment (2%) 5mL, sodium acetate 15mL (pipette), 0.1% o-phenanthroline 5mL, take out to room temperature, add hydrochloric acid 5mL 1mL, in an electric furnace Add the charcoal to the white for 1~1.5h, then place the muffle furnace at 500 600°C and evaporate in an electric furnace (usually 15 minutes). After cooling with 5 mL of hydrochloric acid, it was allowed to stand for 15 min.