Ultra‐Performance Liquid Chromatographic Determination of L‐Ergothioneine in Commercially Available Classes of Cow Milk

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...