Direct sensitive quantitative lC/MS analysis of C-peptide from human urine by two dimensional reverse phase/reverse phase high-performance liquid chromatography.
We describe for the first time the direct quantitative analysis of human C-peptide from urine by isotope dilution assay. Implementation of 2-D reverse phase-reverse phase chromatography (2-D RP-RP) with SIM detection resulted in high assay sensitivity (LOQ= 5 pg on column), accuracy, and method ruggedness. Our experiments demonstrate the strong resolving capability of our proposed 2-D RP-RP platform which significantly reduces strong matrix effects and their resulting quantitation error over a wide range of urine concentrations. In contrast, single column methods (both SIM and multiple reaction monitoring) were found acceptable only for strongly diluted urine samples.
General Clinical Research Center Analytical Core Laboratory and Division of Endocrinology/Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA. rogatsky@aecom.yu.edu
Eduard
E
Rogatsky
Vlad
V
Tomuta
Greg
G
Cruikshank
Louis
L
Vele
Harsha
H
Jayatillake
Daniel
D
Stein
D002096:C-Peptide / Q000737:chemistry / Q000652:urine; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003920:Diabetes Mellitus / Q000378:metabolism; D006801:Humans; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D002096:C-Peptide