Fluorescent Derivatization of Acrylamide with 5-(Dimethylamino)-<i>N</i>-(2-sulfanylethyl)naphthalene-1-sulfonamide for Liquid Chromatography

Acrylamide (AA) is a neurotoxic and potentially carcinogenic compound whose detection in processed foods and food additives has raised significant public health concerns, underscoring the urgent need for sensitive yet straightforward analytical methods. Conventional analytical approaches based on GC or HPLC have limited applicability in case of AA due to its high polarity and low molecular weight. Therefore, various derivatization strategies have been explored; however, challenges remain in terms of selectivity. Herein, we report a novel HPLC-FLD method for AA analysis using 5-(dimethylamino)-N-(2-sulfanylethyl)naphthalene-1-sulfonamide (DNS-SH) as a fluorescent derivatization reagent. DNS-SH was selected to provide moderate hydrophobicity for reversed-phase retention, long-wavelength fluorescence distinct from that of food components, and a reactive thiol group for the selective derivatization of AA. The AA-DNS derivative was structurally confirmed by LC-HRMS, 1D-NMR, and 2D-NMR. The developed HPLC-FLD method exhibited excellent linearity (r² > 0.9999), reproducibility (RSD < 2.76 %), and a low LOQ of 0.1 µg/mL. Its applicability was validated using an “Amino Acid-Monosaccharide Reaction Product,” where AA was detected at 0.1 µg/g in spiked samples. This approach provides a reliable tool for monitoring AA in food additives and potentially broader food matrices.