Recovery of Peptides

In analyzing peptides using reversed phase columns (particularly ODS columns), there is always a concern about a decline in recovery. Therefore Asahipak ODP series should be used, which shows a better recovery in analyzing peptides of high, medium and low molecular weights as well as in analyzing acidic, neutral or basic peptides. The recovery of a number of peptides with a wide range of different characteristics are shown for isocratic elution conditions. With these columns it is possible to get a good recovery by isocratic elution.

Substance(1micro-g each) MW pI HP Recovery(%)
Eluent
A		 Eluent
B		 Eluent
C
Glu-Gly-Phe
Substance P Frg.1-4		 Acidic
Basic		 351
497		 3.29
11.44		 2.17
3.24		 96
100		 103
100		 88
110
Met-Enkephalin
Des-Arg9-Bradykinin		 Neutral
Basic		 574
904		 5.90
11.05		 5.02
7.65		 96
-		 96
98		 99
102
Substance P
alpha-Endorphin		 Basic
Neutral		 1348
1684		 12
6.85		 8.61
6.94		 -
-		 90
96		 105
100
beta-Endorphin
Insulin B chain S-sulphonate
Big gastrin (Human)		 Basic
Neutral
Acidic		 3465
3496
3749		 9.93
6.05
4.32		 16.80
24.05
23.53		 -
-
-		 -
-
-		 100
97
95
PI: Isocratic point, HP: Hydrophorbic Parameter, Acidic: Acidic peptide, Neutral: Neutral peptide, Basic: Basic peptide
Column       : Shodex Asahipak ODP-50 6D (6.0mmID*150mm)
Eluent       : (A); 0.05% TFA aq./CH3CN=85/15
               (B); 0.05% TFA aq./CH3CN=80/20
               (C); 0.05% TFA aq./CH3CN=70/30
Flow rate    : 1.0mL/min
Detector     : UV(220nm)
Column temp. : 30deg-C