Simultaneous Determination of Multiclass Cyanotoxins in Aquatic Products, Vegetables and Algal Dietary Supplements Using Dispersive Solid-Phase Extraction (dSPE)-UHPLC-MS/MS.

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.