Research Progress on Extraction and Analytical Methods for Saxitoxin and Its Congeners

Saxitoxin is a potent neurotoxin commonly found in shellfish, produced by dinoflagellate and cyanobacterial blooms in seawater or fresh water. This review dissects the conventional liquid–liquid extraction (LLE) and solid-phase extraction (SPE) and the emerging microscale sample preparation method, followed by their achievements in the preconcentration of saxitoxin-group toxins from different matrices. Despite the tedious and multi-step procedures, LLE and SPE remain the most applied techniques in detecting saxitoxin due to their high sensitivity and selectivity. Nevertheless, microscale sample preparation offers potential as a green technique, especially in the development of advanced adsorbents for better sensitivity.