High throughput analysis of amnesic shellfish poisoning toxins in bivalve molluscs by dispersive solid-phase extraction and high-performance liquid chromatography using a monolithic column

Domoic acid and its isomers are algal neurotoxins responsible for the human intoxication syndrome known as amnesic shellfish poisoning. A rapid and simple HPLC-UV/DAD method based on the use of a monolithic silica column is proposed for the determination of ASP toxins in shellfish samples. To the best of our knowledge, a monolithic column is applied for the first time to the analysis of marine toxins. An experimental design strategy was employed to evaluate the influence of the main variables potentially affecting the chromatographic separation. Optimal conditions were selected by means of a multi-response optimisation approach, aiming to minimise retention times while maintaining enough resolution between isomers. Dispersive solid-phase extraction (dSPE) is proposed as a complementary cleanup procedure in order to reduce chromatographic interferences and to increase column lifetime. Amongst several sorbents, graphitized non-porous carbon provided the best results. Method performance was evaluated in terms of accuracy, precision, linearity and limits of detection (LODs). Quantitative recoveries (>= 89%) and satisfactory method precision (RSD <= 6%) were obtained. LODs at the nanogram per gram level were achieved. To demonstrate the applicability of the proposed method, several shellfish samples from Northwestern Spain were analysed, including scallops, mussels, Manila clams, common edible cockles and razor clams. (C) 2011 Elsevier Ltd. All rights reserved.