title: Simultaneous analysis of N(ε) -(carboxymethyl)Lysine and N(ε) -(carboxyethyl)lysine in foods by ultra-performance liquid chromatography-mass spectrometry with derivatization by 9-fluorenylmethyl chloroformate.
abstract: Isotope dilution ultra-performance liquid chromatography-electrospray tandem mass spectrometry with derivatization by 9-fluorenylmethyl chloroformate was successfully applied to quantify N(ε) -(carboxymethyl)lysine (CML) and N(ε) -(carboxyethyl)lysine (CEL) in processed foods. We demonstrate that this analytical method is well validated for the determination of CML and CEL contents in processed foods. Relative standard deviations (RSD) indicate repeatability (RSD < 6% for CML and CEL) and reproducibility (RSD < 6% for CML and < 7% for CEL) in this method. Percent recovery is also good. We obtain recoveries of 102% to 112% for CML and 86% to 114% for CEL. CML levels detected in the samples vary from 2.29 to 480 mg/kg food, whereas CEL is detected in significantly lower concentrations ranging from 0.56 to 107 mg/kg food. These data could help consumers make better food choices by monitoring intake of advanced glycation end-products, which may pose a risk to human health.
authors.affiliation: Dept. of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang Univ, Hangzhou, 310058, PR China.
authors.forename: Yanqiong
authors.initials: Y
authors.lastname: Zhou
authors.forename: Qin
authors.initials: Q
authors.lastname: Lin
authors.forename: Cheng
authors.initials: C
authors.lastname: Jin
authors.forename: Lu
authors.initials: L
authors.lastname: Cheng
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zheng
authors.forename: Ming
authors.initials: M
authors.lastname: Dai
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D005449:Fluorenes / Q000737:chemistry; D005504:Food Analysis / Q000379:methods*; D017127:Glycation End Products, Advanced / Q000032:analysis; D006801:Humans; D007202:Indicators and Reagents / Q000737:chemistry; D008239:Lysine / Q000031:analogs & derivatives* / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results
chemical_list: D005449:Fluorenes; D017127:Glycation End Products, Advanced; D007202:Indicators and Reagents; C054688:N(6)-(1-carboxyethyl)lysine; C048496:N(6)-carboxymethyllysine; C054007:1-(9-fluorenyl)methyl chloroformate; D008239:Lysine
keywords: FMOC-Cl derivatization; Nε-(carboxyethyl)lysine (CEL); Nε-(carboxymethyl)lysine (CML); UPLC-MS/MS; processed foods