Nitrone formation: A new strategy for the derivatization of aldehydes and its application on the determination of furfurals in foods by high performance liquid chromatography with fluorescence detection.

A nitrone formation method using a novel fluorescent reagent 4-hydroxylaminopropyl-7-methoxylcoumarin (HAMC) has been developed and applied for the determination of furfurals in foods using high performance liquid chromatography with fluorescence detection (HPLC-FLD). Furfurals samples were derivatized by HAMC in aqueous condition at room temperature in less than 30min and were subjected to direct HPLC-FLD analysis without extra purification or extraction. Compared with other conventional methods, nitrone formation method produced single chromatographic peak for each analyte, leading to simpler chromatograms and enhancing the overall sensitivity. Low detection limits at sub-nM level (0.08-0.1nM) and high repeatabilities (intra-day RSD ≤ 4.2% and inter-day RSD ≤ 6.7%) were achieved. The linear range of the calibration curve was 0.2-4000nM with good correlation coefficients (R ≥ 0.9989). This method was successfully applied for furfurals determination in food samples, including honey and coffee. The accuracy was satisfactory with recoveries ranging from 89.7% to 106.7% Above all, this pre-column derivatization method is simple, reliable and highly sensitive, providing a promising way for future studies of aldehydes from various sources.