These samples were obtained by fractional precipitation of the polymer.

Other methods used in the past were fractional extraction and fractional precipitation.

This property of iron cations is exploited for the fractional precipitation of the two hydroxides in chemical analysis.

He became a professor and head of the chemistry department, separating and identifying rare earth elements by fractional precipitation and crystallization.

Examples of operations include affinity, size exclusion, reversed phase chromatography, ion-exchange chromatography, crystallization and fractional precipitation.

A number of processes have been proposed to purify HfCl from ZrCl including fractional distillation, fractional precipitation, fractional crystallization and ion exchange.

Basicity separation as operated commercially involved the fractional precipitation of the weaker bases (such as didymium) from nitrate solution by the addition of magnesium oxide or dilute ammonia gas.

For the investigations of Scilla glycosides and the first studies in the ergot field, I still used the old separation and purification techniques from Liebig's day: fractional extraction, fractional precipitation, fractional crystallization, and the like.