Determination of paralytic shellfish toxins using potentiometric electronic tongue

The present work deals with the application of an electronic tongue based on potentiometric chemical sensors to the detection of paralytic shellfish toxins (PSTs) in bivalve extracts. PSTs are naturally occurring toxic compounds produced by some phytoplankton species that may accumulate in bivalves during algal blooms. Bivalves for human consumption are therefore monitored for PSTs. Electronic tongue comprised six miniaturized sensors with solid inner contact and plasticized polyvinylchloride membranes. Calibration models were calculated by PLS regression using measurements in sixteen model mixed solutions containing four PSTs commonly detected in bivalves harvested in the Portuguese coast. Transfer of the calibration models to sample matrix was done by joint-PLS regression using measurements in five mussel extracts spiked with PST standards. Quantification of PSTs in extracts of naturally contaminated mussel using electronic tongue and updated calibration model was in agreement with measurements by the reference chromatographic method.