MOISTURE DETERMINATION IN CRUDE DRUGS BY THE KARL FISCHER METHOD

Summary

The use of Karl Fischer reagent for the determination of moisture in powdered crude drugs is investigated. The accuracy of the method is shown to depend on the particle size of the powder and on the contact time between the sample and excess reagent. A relationship between the time in contact and the crude fibre content of the drug is demonstrated. Optimum values for particle size and contact time are suggested. These could lead to the general use of Karl Fischer reagent as an accurate and rapid method for the determination of moisture in crude drugs.