Manufacture of algal chemicals. II. Laboratory‐scale isolation of mannitol from brown marine algae

Abstract
Methods for the isolation of mannitol from the common brown algae indigenous to Great Britain have been worked out on the laboratory scale with a view to the ultimate development of a process suitable for large‐scale production. These comprise (i) solvent extraction of the dried seaweed and (ii) dilute‐acid extraction of the fresh or dried seaweed, followed by evaporation of the extract to dryness and the isolation of mannitol from this extract by (a) solvent extraction (b) precipitation as a water‐insoluble derivative or (c) the use of ion‐exchange resins.