Mother liquor

The liquid from which a desired substance in the form of crystals has separated out during the substance purification by recrystallization is called mother liquor . The crystals can be separated off from their mother liquor by decanting or filtration .

Mother liquors contain residues of the crystallized substance and the original impurities, which can often be extracted from these solutions in a subsequent step. Likewise, after part of the solvent has evaporated, a second crystal fraction of the desired substance can often be obtained by cooling . This second crystal fraction is usually not as “clean” (chemically homogeneous) as the first crystal fraction.

Mother liquors obtained in industrial processes are sometimes recycled in order to optimize the yields.

Individual evidence

1. ^ Walter Wittenberger: Chemische Laboratoriumstechnik , Springer-Verlag, Vienna, New York, 7th edition, 1973, p. 129, ISBN 3-211-81116-8 .
2. ↑ Otto-Albrecht Neumüller (Ed.): Römpps Chemie-Lexikon. Volume 4: M-Pk. 8th revised and expanded edition. Franckh'sche Verlagshandlung, Stuttgart 1985, ISBN 3-440-04514-5 , p. 2696.
3. ^ Brockhaus ABC Chemie , VEB FA Brockhaus Verlag Leipzig 1965, p. 910.
4. ^ Walter Wittenberger: Chemische Laboratoriumstechnik , Springer-Verlag, Vienna, New York, 7th edition, 1973, pp. 217-218, ISBN 3-211-81116-8 .