High-performance liquid chromatography with post-column fluorescence derivatization for accurate detection of multi-alkylresorcinols in grain products.

Alkylresorcinols (ARs), recognized for their bioactivity and as biomarkers for whole grains, were sensitively determined using high-performance liquid chromatography (HPLC) with post-column fluorescence derivatization. Dopamine (DA) was employed as the fluorescence derivatizing agent, which rapidly reacts with ARs to produce strong fluorescence, thereby enhancing sensitivity and anti-interference. The method effectively determined five ARs homologs, including 5-heptadecylresorcinol (C17:0), 5-nonadecylresorcinol (C19:0), 5-heneicosylresorcinol (C21:0), 5-tricosylresorcinol (C23:0), and 5-pentacosylresorcinol (C25:0). Optimal detection conditions are column temperature at 32 °C, 0.5 mg/mL of DA, buffer pH 13, and flow rate at 0.5 mL/min. These homologs were detectable in the range of 0.2-20,000 ng/mL, with limits of detection between 0.015 and 0.040 ng/mL, outperforming previous methods. Recovery rates for spiked samples were between 98.96 % and 107.92 %, with relative standard deviations below 4.73 %. This validated method accurately detected ARs in cereal products, offering significant potential for nutritional quality assessments and promoting whole grain health benefits.