Dictionary:

fractionate

  (frăk'shə-nāt')

1. To divide or separate into parts; break up: “In the post-Watergate era, power has been fractionated on Capitol Hill” (Evan Thomas).
2. To separate (a chemical compound) into components, as by distillation or crystallization.

1. in radiotherapy, division of the total dose of radiation into small doses given at intervals.
2. in chemistry, separation of a substance into components, as by distillation or crystallization.
3. in histology, isolation of components of living cells by differential centrifugation.

The verb has 2 meanings:

Meaning #1: separate into constituents or fractions containing concentrated constituents; in chemistry

Meaning #2: obtain by a fractional process; in chemistry