# Commission Regulation (EC) No 152/2009 of 27 January 2009 laying down the methods of sampling and analysis for the official control of feed (Text with EEA relevance), Division 9.1: Following special chromatographic conditions may give better separation between tryptophan and α-methyl-tryptophan.

Extent: E+W+S+N.I.

Isocratic elution followed by gradient column cleaning:
Liquid chromatographic column:
125 mm x 4 mm, C18, 5 μm packing or equivalent
Column temperature:
32 oC
Mobile phase:
A: 0,01 mol/l KH2PO4/méthanol, 95+5 (V+V).
B: methanol
Gradient program:
0 min.
100 % A
0 % B
15 min.
100 % A
0 % B
17 min.
60 % A
40 % B
19 min.
60 % A
40 % B
21 min.
100 % A
0 % B
33 min.
100 % A
0 % B
Flow rate:
1,2 ml/min.
Total run time:
approx. 33 min.

---
Source: https://www.legislation.gov.uk/eur/2009/152/annex/III/division/G/division/9/division/9.1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2009-152/annex-III/division-G/division-9/division-9.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.