Ethyl Glucuronide (EtG) Derivatization With N‐(3‐Dimethylaminopropyl)‐N′‐Ethylcarbodiimide (EDC). LC‐HRAM‐Orbitrap‐MS Characterization of Derivatives and Application to Blood, Urine, and Hair Analysis

EtG-EDC derivatives demonstrate efficient chromatographic performance on reversed-phase LC columns and undergo protonation easily in the MS ion source, enabling MS detection under positive ionization conditions. The derivatization is simple, fast, reproducible, inexpensive, and safe, as it is obtained in 30 min at low temperatures, starting from a commercially available carbodiimide, without organic solvents and catalyzing agents. This analytical strategy offers a novel approach to detect EtG in biosamples by combining the benefits of chemical derivatization and high-resolution mass spectrometry.