Interference-free analysis of aflatoxin B1 and G1 in various foodstuffs using trilinear component modeling of excitation–emission matrix fluorescence data enhanced through photochemical derivatization

Abstract

A novel ‘dilute-and-shoot’ analytical strategy coupling a self-weighted alternating normalized residue fitting (SWANRF) algorithm with two-dimensional fluorescence detection enhanced through photochemical derivatization (PD) was proposed in the present work for rapid, simultaneous and accurate quantitative analysis of aflatoxin B₁ and G₁ in various foodstuffs (including cereals, honey, and edible oil). By coupling the predominant second-order advantage of the SWANRF algorithm with the ultra-sensitivity of fluorescence detection enhanced through off-line photochemical derivatization, the specific quantitative information of both analytes could be successfully extracted from heavily interferential matrices without complicated multi-step purification and chromatographic separation procedures. Consequently, the whole analytical time and expense were significantly decreased, accurate recoveries (with relative standard deviations, RSDs) (93.5 ± 6.6–102.8 ± 4.0% for AFB₁, and 96.4 ± 3.6–107.2 ± 6.0% for AFG₁) and extremely low limits of detection (LODs) (0.12–0.21 ng mL⁻¹ for AFB₁, and 0.27–0.75 ng mL⁻¹ for AFG₁) were obtained for analytical foodstuff matrices. In addition, all quantitative results of this proposed strategy were carefully compared with the standard IAC-LC-ESI⁺-MS method for further confirmation, which proved that SWANRF-EEMs are promising as an alternative analytical strategy for the routine analysis of multiplex aflatoxins, and a theoretical basis for developing portable detecting devices.