1.7.1 Sample Preparation
The first and foremost step is the sample preparation. The plant material is reduced to a moderately coarse powder by appropriate means using grinders and sieves, to facilitate maximum effective contact of the solvent with the ruptured alkaloid bearing tissues and cells. In the case of plant substances that are rich in oils and fats, such as: seeds, kernels, these non-alkaloidal chemical components need to be eliminated completely by extraction with a suitable non-polar solvent like nhexane, light petroleum ether, in a soxhlet apparatus, which would not extract the alkaloids in question.
However, it is always advisable to shake the light-petroleum ether or n-hexane fraction with a dilute mineral acid and subsequently test the acidic solution for the presence of alkaloids.
