Simultaneous Determination of Multiclass Cyanotoxins in Aquatic Products, Vegetables and Algal Dietary Supplements...

Cyanotoxins, prevalent in eutrophic aquatic ecosystems, pose significant health risks via contaminated food, yet analytical methods for detecting multiple toxin classes in foodstuffs remain limited. In the current study, a method based on dispersive solid-phase extraction (dSPE) coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed to simultaneously determine four common classes of cyanotoxins (i.e., microcystins, cylindrospermopsins, nodularins, and anatoxins) in aquatic products, vegetables and algal dietary supplements. Following initial extraction with 80% aqueous methanol, sample purification was performed using anhydrous sodium sulfate (400 mg) and C₁₈ sorbent (50 mg). For plant-based foods, additional graphitized carbon black (GCB, 15 mg) was also included. The method was successfully validated in eight different food matrices, demonstrating recoveries of 65-122% and relative standard deviations below 19%. The limits of detection and quantification across all matrices ranged from 0.1 to 3.4 μg/kg dry weight (dw) and 0.4 to 11.4 μg/kg dw, respectively. When applied to 96 food samples, this method detected multiple cyanotoxins in Tilapia and Spirulina-based dietary supplements. The proposed method provides a rapid, cost-effective, high-throughput, and sensitive analytical tool suitable for monitoring multiple cyanotoxins in various foodstuffs.