Establishment of the liquid fluorometric method for determination of alkylresorcinols in whole wheat

Abstract

Objective To determine the quality of whole wheat products, it is necessary to establish a method for determination of alkylresorcinols(ars) which are the markers of whole wheat, black wheat and other cereal products. Methods Taking wheat and black wheat as main research₂o₂bjects, factorial design was used to investigate the effect of extraction reagents(acetone, alcohol, and ethyl acetate), extraction methods(ultrasound for 30 min, 60 min, shaking at room temperature overnight), and sample status(granule, flour) on the determination of ars. And ars detection conditions was established by comparing chromatographic conditions and scanning fluorescence wavelengths. The ars content in some commercially available cereals were determined based on the methodological evaluation. Results Taking into account the toxicity of the reagents and efficiency, it was better that the comminuted sample was ultrasonically extracted with ethanol for 30 min before loading on the Waters CORTES-C18 column with ethanol: acetonitrile(30: 70, v: v). The fluorescence detector was set at a wavelength of 272 nm for excitation and 296 nm for emission to detect ars. The linear range was 0.050-10.0g/mL and the coefficient R²≥0.9999. RSD of precision experiment was less than 5% and the spiked recovery rates of three levels were 94.5%-104%. The total amount of ars was 47.9-54.3 mg/100g in commercially available wheat and 53.6-60.9 mg/100g in black wheat. Conclusion The liquid-fluorescence method established in this study can effectively and rapidly separate ars from wheat and black wheat and has the advantages of simple operation, high sensitivity and accuracy.