Analysis of Paralytic Shellfish Toxin (Saxitoxin) in Mollusks by Capillary Zone Electrophoresis

Abstract

Contamination of seafood by paralytic shellfish toxins is considered a public health hazard by the U.S. Food and Drug Administration. Human consumption of bivalves including clams, oysters, and mussels which have accumulated significant levels of Saxitoxins (STXs) is known as paralytic shellfish poisoning (PSP). The STXs are a group of structurally related purines which inhibit neurological transmission to nerves and muscles by reversibly binding to sodium channels. The major sources of saxitoxins are the dinoflagellates Alexandrium spp., Pyrodium bahamense var. compressa, and Gymnodinium catenaturn. The official method for the detection of the saxitoxins is a non-specific mouse bioassay. Recently, HPLC procedures have been reported to separate and quantify the saxitoxins. These methods, however involve extensive sample clean-up and derivatizations. A simple and selective analysis of a saxitoxin (STX) in mollusks by capillary zone electrophoresis (CZE) utilizing UV detection, was developed. Detection of saxitoxin was linear over a wide range of STX concentrations, ranging from 0.75ppm to 50ppm (correlation coeffiecient r=0.999), and the coefficient of variation (n=5) for migration and peak area response were less than 1% and 3%, respectively.