Steam distillation is applied in laboratories for the fractionation of water insoluble liquids or solids according to Dalton's law of partial pressures in a gas mixture.
It is also used for the stripping of chemicals from mixtures or solutions after displacement of ionic equilibria by adding acids or bases, as in the well known Kjeldahl's method for total Nitrogen determination.
The method takes its name from the Danish chemist that conceived it more than a century ago.
The Kjeldahl method is still the most used for determining Nitrogen and protein contents in foods and feeds (official methods).
This is simply due to its precision and reproducibility.
From its first setting-up many improvements were introduced aimed at reducing energy consumption, space requirement and sample weight.