How to Check the Ash Content of HPMC
Checking the ash content of Hydroxypropyl Methylcellulose (HPMC) involves a process of combustion to determine the residue left behind after burning off the organic components. Here's a basic guide:
1. Equipment and Materials:
2. Weighing the Crucible:
Weigh a clean and dry crucible using an analytical balance. Record the weight accurately.
3. Adding HPMC Sample:
Clear the tare (crucible), weigh HPMC sample 1~2 grams, accurate it it to the fourth digitals after zero dot, record the weight precisely.
Make sure the sample is representative of the entire batch.
4. Ignite the Sample:
Put the crucible and HPMC on the electric stove，turn on the switch to the maxmium level. Burn off the samples until there is no smoke emitting.
Pick the curcible off the eletric stove and cool it to the ambient temperature, and then drop around 2ml Concentrated sulfuric acid to the crucible, it will turn the residue into Sulfate.
The residue content is indicated with Sodium sulfate content.
Next, put the crucible on the stove again, continue to burn them until no smoke.
Finally, pick it off and cool it to the room temperture in a desiccator.
5. Cooling and Weighing:
Allow the crucible to cool in a desiccator to prevent absorption of moisture. Weigh the crucible with the ash.
6. Calculating Ash Content:
Calculate the ash content using the formula:
7. Interpretation:
The result represents the percentage of inorganic residue or ash in the HPMC sample.
Remember to follow safety protocols when working with high temperatures, and ensure that the equipment is clean and dry to obtain accurate results. Always refer to the specific standard or method recommended for testing HPMC ash content in your industry or laboratory.