Isotope dilution ESI-LC-MS/MS for quantification of free and total Nε-(1-Carboxymethyl)-l-Lysine and free Nε-(1-Carboxyethyl)-l-Lysine: Comparison of total Nε-(1-Carboxymethyl)-l-Lysine levels measured with new method to ELISA assay in gruel samples.

Summary, in English

ESI-LC-MS/MS method with isotope dilution and SPE based on cation-exchange was developed for determination of free and total Nε-(1-Carboxymethyl)-l-Lysine (CML) and free Nε-(1-Carboxyethyl)-l-Lysine (CEL). The use of nonafluoropentanoic acid in mobile phase was omitted, SPE recoveries of 82±3% and 91±10% (n=6) for CML and CEL respectively and, calibration curves (R(2)>0.9985) were attained. The method was applied to gruel samples and LoQ for the method was 5ng/ml, RSD <10% and accuracy was 115%. Total CML levels in the gruel samples varied from 103-408mg/kg protein. Free CML levels which were 1000 times lower than total CML were three times higher than free CEL levels. CML in a gruel sample was 127±7, 84±9 and 253±28mg/kg using the current ESI-LC-MS/MS, ELISA and GC-MS respectively. The described method has advantages over ELISA with respect to reproducibility and specificity and over GC-MS with respect to reproducibility.

• Author: Eden Tareke; Anna Forslund; Christian Lindh; Christer Fahlgren; Elin Östman
• Department/s: Division of Food and Pharma; Division of Occupational and Environmental Medicine, Lund University
• Publishing year: 2013
• Language: English
• Pages: 4253-4259
• Publication/Series: Food Chemistry
• Volume: 141
• Issue: 4
• Links: http://dx.doi.org/10.1016/j.foodchem.2013.07.003
• Document type: Journal article
• Publisher: Elsevier
• Topic: Food Science
• Status: Published
• Project: ANTIDIABETIC FOOD CENTRE
• ISBN/ISSN/Other: ISSN: 1873-7072