title: Isotopic labelling of peptides and isotope ratio analysis using LC-ICP-MS: a preliminary study.
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.
authors.affiliation: University of Plymouth, Speciation and Environmental Analysis Research Group, School of Earth, Ocean and Environmental Sciences, Drake Circus, Plymouth, PL4 8AA, UK.
authors.forename: Pritesh
authors.initials: P
authors.lastname: Patel
authors.forename: Phil
authors.initials: P
authors.lastname: Jones
authors.forename: Richard
authors.initials: R
authors.lastname: Handy
authors.forename: Chris
authors.initials: C
authors.lastname: Harrington
authors.forename: Peter
authors.initials: P
authors.lastname: Marshall
authors.forename: E Hywel
authors.initials: EH
authors.lastname: Evans
mesh_terms: D001920:Bradykinin / Q000032:analysis* / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods*; D005063:Europium / Q000737:chemistry; D007554:Isotopes / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D013373:Substance P / Q000032:analysis* / Q000737:chemistry*
chemical_list: D007554:Isotopes; D013373:Substance P; D005063:Europium; D001920:Bradykinin