Development of a liquid fluorometric method for the quantification of Alkylresorcinols in whole wheat

Abstract

Objective: To assess the quality of whole wheat products, a method for determining alkylresorcinols (ARs)—markers of whole wheat, black wheat, and other cereal products—was developed. Methods: The study focused on wheat and black wheat, using factorial design to evaluate the impact of extraction solvents (acetone, alcohol, and ethyl acetate), extraction techniques (ultrasonic extraction for 30 or 60 minutes, and shaking overnight at room temperature), and sample forms (granules or flour) on AR determination. AR detection conditions were optimized by comparing chromatographic settings and fluorescence scanning wavelengths. The method's effectiveness was validated by measuring AR content in various commercially available cereals. Results: Considering reagent toxicity and efficiency, the optimal procedure involved ultrasonically extracting comminuted samples with ethanol for 30 minutes, then analyzing with a Waters CORTES-C18 column using an ethanol: acetonitrile (30:70, v:v) mobile phase. Fluorescence detection was performed at an excitation wavelength of 272 nm and an emission wavelength of 296 nm. The method had a linear range of 0.050–10.0 µg/mL with an R² ≥ 0.9999. Precision experiments showed an RSD of less than 5%, and spiked recovery rates ranged from 94.5% to 104%. The total AR content was 47.9–54.3 mg/100 g in commercially available wheat and 53.6–60.9 mg/100 g in black wheat. Conclusion: The liquid-fluorescence method established in this study effectively and rapidly separates ARs from wheat and black wheat, offering advantages of simplicity, high sensitivity, and accuracy.