Page 13 - Pharmd general phytochemistry I-Final2024_LEUCTERS

Hydrodistillation Apparatus

Disadvantages of the distillation method:

1- The high temperature in the presence of water during distillation
induce hydrolysis of esters and removal of water from tertiary
alcohols.

2- Volatile amines and volatile degradation products of carbohydrates
(furfural) pass over during distillation and contaminate the V.O.

3- Loss of water-soluble components of V.O is the water layer. The
distillation water contains small amounts of dissolved volatile oil and
is often returned to the distillation still in order to recover the
dissolved oil. This process is called Cohobation (Redistillation of
water).

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