Subjective: To Determine moisture content of crude drug by loss on drying method.
Theory:
Moisture content is determined via a thermogravimetric method i.e. by loss on drying. In which, the sample is heated & the weight loss due to evaporation of moisture is recorded.
Requirements:
Apparatus: Porcelain dish, spatula, tongs, digital weighing machine, hot air oven, desiccator.
Chemicals: Sample of crude drug (0.5gm)
Procedure:
- Weigh the empty porcelain dish and note the reading.
- Take the sample of crude drug in porcelain dish.
- Weigh the porcelain dish with sample in it and note the reading.
- Keep the porcelain dish in pre-heated hot air oven for 15 minutes at 100°C – 105°C.
- After heating, keep the porcelain dish in desiccator for 15 minutes.
- Take out the dish from desiccator, and weigh the porcelain dish with dried sample.
- Repeat the drying in the oven using above steps till a constant weight not obtained.
- After determining the constant weight, note the reading and calculate the percent moisture content.
Conclusion:
Percent moisture content in the given sample of crude drug is ______ .