title: Ultra-performance liquid chromatographic determination of L-ergothioneine in commercially available classes of cow milk.
abstract: A new efficient and sensitive precolumn hydrophilic interaction ultra-performance liquid chromatography (HILIC-UPLC) method was established for the quantitative determination of L-ergothioneine (ERT) in milk. After derivatization of ERT with 7-diethylamino-3-[4-(iodoacetamido)phenyl]-4-methylcoumarin, chromatographic separation was achieved in a fairly short time, less than 5 min, on a 100 × 2.1 mm Waters Cortecs UPLC HILIC 1.6-μm column, by using a mixture of 30 mmol/L ammonium acetate/acetonitrile (10:90, v/v) as a mobile phase flowing isocratically at 0.9 mL/min. Limit of detection and the limit of quantification were 0.03 and 0.10 μmol/L, respectively. The method exhibited linearity in a concentration range of 0.16 and 5.08 μmol/L. Mean recovery was 106.66%, whereas intra- and interassay precisions were determined to be within 6 RSD%. On average, ERT concentration in different commercially available classes of cow milk was found to be 0.442 ± 0.191 μmol/L, with the highest levels in the ultra-high temperature milks and low values in the unprocessed and HTST whole milks. In this light, our experiments suggest that ERT could be used as a marker for the heat treatment of milk.
authors.affiliation: Dept. of Biomedical Sciences, Univ. of Sassari, Sassari, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Sotgia
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Pisanu
authors.forename: Debora
authors.initials: D
authors.lastname: Cambedda
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Pintus
authors.forename: Ciriaco
authors.initials: C
authors.lastname: Carru
authors.forename: Angelo
authors.initials: A
authors.lastname: Zinellu
mesh_terms: D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid; D003374:Coumarins / Q000737:chemistry; D004880:Ergothioneine / Q000032:analysis* / Q000737:chemistry; D005260:Female; D005513:Food Inspection / Q000379:methods; D057927:Hydrophobic and Hydrophilic Interactions; D008892:Milk / Q000737:chemistry*
chemical_list: D003374:Coumarins; D004880:Ergothioneine
keywords: DCIA; HILIC; UPLC; ergothioneine; heat treatment