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Updated: Jul 13, 2026

Sample Preparation and Relative Quantitation using Reductive Methylation of Amines for Peptidomics Studies
Published on: November 4, 2021
Isotopic labelling of peptides and isotope ratio analysis using LC-ICP-MS: a preliminary study
Pritesh Patel1, Phil Jones, Richard Handy
1University of Plymouth, Speciation and Environmental Analysis Research Group, School of Earth, Ocean and Environmental Sciences, Drake Circus, Plymouth, PL4 8AA, UK.
Abstract:
Bradykinin and substance P have been derivatised with cyclic diethylenetriaminepentaacetic anhydride (cDTPA) and subsequently labelled with natural and isotopically enriched Eu(3+). This enabled the detection and relative quantitation of the peptides using element-selective detection by high-performance liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS). Relative quantitation was achieved by differentially labelling two peptide sources, after derivatisation with cDTPA, using natural and enriched (151)Eu respectively. The (151)Eu:(153)Eu isotope ratio was measured and used to calculate the original peptide ratio. The measured ratios came within 5.2% of the known ratio. Derivatisation and chelation reactions were additionally confirmed using LC-ESI-MS.
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