Study of solid phase adsorption of paralytic shellfish poisoning toxins (PSP) onto different resins

Abstract

A computationally designed polymer (CDP), based on the functional monomer ethylene glycol methacrylate phosphate (EGMP), with a reported high specific affinity for the neurotoxic paralytic shellfish poisoning (PSP) toxins saxitoxin (STX) and neosaxitoxin (neoSTX) was evaluated with a view to it being used in a solid phase adsorption toxin tracking (SPATT) system for deployment in the marine environment. In addition, a synthetic resin adsorbent (SEPABEADS ® SP700) which had previously shown to adsorb lipophilic shellfish toxins (LSTs) from seawater was also assessed. Adsorption and desorption of the PSP toxin analogues on and from the CDP polymer and the SP700 resin were investigated. Both adsorbents were contained within dialysis membrane bags and deployed in PSP toxins-spiked seawater and in cultures of Alexandrium tamarense known to be producing PSP toxins. Additionally, some bags holding SP700 resin were also deployed in a mixture of dinoflagellate cultures composed of A. tamarense and Prorocentrum lima, the latter being a diarrheic shellfish toxins (DSP) producer. The polymer and the resin were extracted and analysed for PSP toxins using high performance liquid chromatography (HPLC). In addition, the SP700 resin was also analysed for DSP toxins using liquid chromatography–mass spectrometry (LC–MS). The results indicated that both CDP and SP700 are suitable for the adsorption of a wide range of PSP toxins for a limited period of time (3–7 days). The CDP appears to be more appropriate because it adsorbs higher quantities of PSP toxins, however SP700 adsorbing PSP and DSP toxins over the same range seems to be more useful. PSP toxins can be easily removed from both materials with rinse water or in a toxin-free medium. In summary, either CDP or SP700 could be used as an early warming system for the monitoring of harmful algal blooms (HAB) responsible for PSP poisoning found in European coastal waters.