Division 9 Observations

United Kingdom

1. 9.1Following special chromatographic conditions may give better separation between tryptophan and α-methyl-tryptophan.
2. 9.2The chromatography will vary according to the type of HPLC and column packing material used. The chosen system must be capable of giving baseline separation between the tryptophan and the internal standard. Moreover it is important that degradation products are well separated from the tryptophan and the internal standard. Hydrolysates without internal standard shall be run in order to check the base line under the internal standard for impurities. It is important that the run time is sufficiently long for the elution of all the degradation products, otherwise late eluting peaks may interfere with subsequent chromatographic runs.
3. 9.3Barium hydroxide