. Author manuscript; available in PMC: 2013 Mar 23.

Published in final edited form as: J Chromatogr A. 2012 Jan 25;1230:30–40. doi: 10.1016/j.chroma.2012.01.053

Table 2.

RP-HPLC Retention Time Differences (Δt_R) Between Peptide Pairs of the Same Composition and Minimal Sequence Variation

Peptide Pairs^a	C₈^b		C₁₈		Hydro		Fusion		Polar		PH

	CH₃CN^c	MeOH	CH₃CN	MeOH	CH₃CN	MeOH	CH₃CN	MeOH	CH₃CN	MeOH	CH₃CN	MeOH
AmN-Y/AmC-Y	4.3^d	3.1	3.9	2.9	4.2	3.5	6.1^*	5.1^*	3.1	4.0	2.8	3.1
AmN-F/AmC-F	2.6	1.0	2.4	1.8	2.8	2.5	5.4^*	4.4^*	2.1	2.0	1.5	1.3
AcN-Y/AcC-Y	4. 6	4.0	3.7	3.7	4.0	4.7	6.8^*	6.3^*	2.2	4.5	2.1	3.6
AcN-F/AcC-F	1.9	2.1	1.5	2.4	1.9	3.1	5.2^*	5.0^*	0.4	2.1	0.3	1.7
AmN-A/AmC-A	3.4	2.4	3.2	2.3	3.5	2.7	4.9^*	4.3^*	3.5	3.5	3.0	2.6
AmN-V/AmC-V	0.5	0	0	0	0	0	1.8^*	1.5^*	1.0	1.5	0.5	0.8
AcN-A/AcC-A	2.7	2.8	2.6	2.8	2.8	2.9	4.1^*	4.0^*	1.7	2.7	1.6	2.2
AcN-V/AcC-V	0.6	0	1.4	0	1.2	0	1.7^*	2.3^*	0.8	1.8	1.3	0.9
AmN-I/AmC-I	0.7	0.3	0	0.7	0	0	2.7^*	2.0^*	1.3	1.9	0.6	1.0
AcN-I/AcC-I	0.4	0	1.6	0	1.4	0	1.8^*	2.4^*	0.9	1.8	1.6	0.9

Sequences and denotions of peptides are shown in Table 1.

Descriptions of columns shown in Section 3.2.

RP-HPLC conditions for both CH₃CN and MeOH mobile phases are shown in Section 2.3.

Retention time differences in min.

^e For the majority of peptide pairs, analogues with the amino acid substitution towards the N-terminal were eluted prior to those substituted towards the C-terminal (Table 1); the bold, italicized values represent values where this situation was reversed.

Denotes best Δt_R values on the six columns tested.