PROCESS FOR THE EXTRACTIVE SEPARATION OF L-PHOSPHINOTHRICIN AND L-GLUTAMIC ACID IN AQUEOUS SOLUTION

摘要

A large number of customary processes for separating amino acids fails when very polar hydrophilic amino acids with isoelectric points (IEP) which are close to one another are to be fractionated. Mixtures of L-glutamic acid (IEP=3.24) and L-phosphinothricin (IEP=2.6) produced by enzymatic transaminations of the corresponding alpha -keto acid have been difficult to separate to date. The invention relates to a process for separating L-phosphinothricin and L-glutamic acid, which comprises carrying out the separation as liquid/liquid extraction with two non-miscible aqueous phases as phase system, where the phase former contained in the phase system is a combination of at least two different water-soluble polymers or of at least one water-soluble salt and one water-soluble polymer, and the extraction is carried out by multistage countercurrent partition on the van Dijck principle.