Capillary electrophoresis-based immunoassay for the determination of brevetoxin-B in shellfish using electrochemical detection.

Neurotoxic shellfish poisoning is a significant food-borne disease caused by potent cyclic polyether toxins (brevetoxins) that accumulate in the flesh of shellfish. Here we report a new procedure for brevetoxin analysis by capillary electrophoresis-based immunoassay (CE-IA) with electrochemical (EC) detection. In this method, after the competitive immunoreaction in liquid phase, the horseradish peroxidase (HRP)-labeled antigen and the bound enzyme-labeled complex were separated and then the system of HRP catalyzing H(2)O(2)-o-aminophenol reaction was adopted. The limits of detection (signal-to-noise = 3) was determined to be 0.1 ng/mL. Intra-day relative standard deviations (RSD, n = 5) for migration time and peak area were 3.6 and 4.5%, respectively. Inter-day RSD was 6.9 and 7.8% for migration time and peak area, respectively. The CE-IA with EC detection provides a sensitive analytical approach, not previously available, for the determination of brevetoxin-B in shellfish samples.