Selective and Efficient Capture and Release of vic-Diol-Containing Pacific and Caribbean Ciguatoxins from Fish Extracts with a Boronate Affinity Polymer.

Abstract

Ciguatera poisoning can occur following the consumption of fish contaminated with trace levels of ciguatoxins (CTXs). These trace levels represent an analytical challenge for confirmation by LC-MS due to matrix interferences and the high instrument sensitivity required. Sample preparation procedures are laborious and require extensive cleanup procedures to address these issues. The application of a selective isolation technique employing boronate affinity polymers was therefore investigated for the capture of vic-diol-containing Caribbean and Pacific CTXs from fish extracts. A dispersive SPE procedure was developed where nearly complete binding of CTXs in fish extracts occurred with boric acid gel in less than 1 h. Release of the bound CTXs resulted in >95% recovery of C-CTX1/2, C-CTX3/4, CTX1B, 54-deoxyCTX1B, and 52-epi-54-deoxyCTX1B from the extracts. This selective extraction tool has the potential to greatly simplify both analytical sample preparation and preparative extraction and isolation of CTXs for structure elucidation and production of standards.