On-line capillary isoelectric focusing-mass spectrometry for quantitative analysis of peptides and proteins.
J Pharm Biomed Anal
; 37(3): 423-8, 2005 Mar 09.
Article
in En
| MEDLINE
| ID: mdl-15740899
ABSTRACT
On-line capillary isoelectric focusing-mass spectrometry (cIEF-MS) was applied to determine concentrations of peptides and proteins using angiotensin II and human tetrasialo-transferrin as the model samples. The concentration of the carrier ampholyte was optimized for both resolution and ion intensity. cIEF-MS employing 1% Pharmalyte 3-10 and a sheath liquid containing water/methanol/acetic acid (50/49/1) resolved angiotensin I and II (5 microM each, DeltapI=0.2) at an Rs value of 2.29. The determined concentration of angiotensin II (0.1-5 microM) well correlated (R=0.999) with that obtained by the conventional RP-HPLC method. The limit of detection was 0.22 microM, which was about 10 times lower than that by UV detection (2 microM). The repeatability and accuracy were <15 and <11%, respectively. cIEF-MS was also applied to determine human tetrasialo-transferrin concentration. The good linearity (R2=0.998) was also observed between the transferrin concentration (0.5-1.2 g/L) and peak area ratio (IS; beta-lactoglobulin B) with acceptable accuracy (<1.9%) and repeatability ( approximately 10% at 1g/L).
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Peptides
/
Online Systems
/
Proteins
Limits:
Animals
/
Humans
Language:
En
Journal:
J Pharm Biomed Anal
Year:
2005
Document type:
Article
Affiliation country:
Japan