Application of Solid Phase Adsorption Toxin Tracking (SPATT) for field detection of the hydrophilic phycotoxins domoic acid and saxitoxin in coastal California

Abstract

Recent publications have identified the analysis of phycotoxins in sentinel shellfish as a problematic tool for environmental monitoring purposes. Domoic acid (DA), a neurotoxin produced by some species of the diatom Pseudo‐nitzschia, can remain undetected in sentinel shellfish stocks during toxic blooms and subsequent marine bird and mammal mass mortality events. Solid Phase Adsorption Toxin Tracking (SPATT) has previously been described for monitoring of lipophilic toxins, whereas resin‐based sampling methods are routinely employed for many other environmental contaminants. Here, we evaluate the applicability of SPATT for monitoring the hydrophilic phycotoxin DA and demonstrate that the same field sampling methods can be used for the detection of saxitoxins. We present laboratory‐based adsorption profiles characterizing the performance of SPATT with four resin types: (1) HP20, (2) SP700, (3) SP207, and (4) SP207SS. We present results from 17 mo of approximately weekly SPATT deployments in Monterey Bay, California (USA); this period included two significant toxigenic Pseudo‐nitzschia bloom events as well as low‐level saxitoxin events. SPATT signaled the presence of DA 3 and 7 weeks before the recognition of bloom conditions by traditional monitoring techniques (7 and 8 weeks before shellfish toxicity). Under ambient (non‐bloom) conditions, all resins detected DA when its presence was not apparent from traditional monitoring, highlighting the ubiquity of low level or transient toxin events in the environment. This study is the first to evaluate SPATT deployments in U.S. waters, and the first to demonstrate the applicability of SPATT toward detection of hydrophilic phycotoxins in the field.

Pseudo-nitzschia physiological ecology, phylogeny, toxicity, monitoring and impacts on ecosystem health

“…Sentinel shellfish, typically mussels in cages, may not always provide the best warning of DA events. Alternatives to mussels, including crustaceans that retain toxins , or solid phase adsorption toxin tracking (SPATT) technology (Lane et al, 2010) can provide a more effective ''history'' of DA in the phytoplankton assemblage or in shellfish.…”

Mechanism and application of solid phase adsorption toxin tracking for monitoring microcystins

“…HP20 resin was previously shown to adsorb the hydrophilic toxin domoic acid slower than SP700 [16]. Different aqueous methanol solutions were compared for the desorption of microcystins from HP20 and SP700.…”

“…Variations of SPATT, including sewn bags [10,11], packed columns [12], PVC frames [13], and embroidery discs [14,15], have been used for monitoring lipophilic toxins in the marine environment. Of the adsorbents used to date, the aromatic resin DIAON HP20 has proven particularly efficient in monitoring a wide range of marine and fresh water biotoxins, including the hydrophilic phycotoxins domoic acid and saxitoxin [16], microcystins [7,[17][18][19], and anatoxins [20]. Pore size distribution has been found to significantly influence the adsorption capacity of the aromatic resins HP20 and SP700 for diarrhetic shellfish toxins [21].…”

Investigation of Algal Biotoxin Removal during SWRO Desalination through a Materials Flow Analysis

“…Only dissolved concentrations obtained by grab sampling as opposed to passive sampling methods (SPATT) were included in this analysis given that it is not currently possible to directly compare or extrapolate SPATT measurements (µg/g resin) to ambient concentrations (µg/L). SPATT integrates sampling both spatially and temporally and, in many cases, has been evidenced to be more sensitive than grab sampling methods [31,32]. Although adsorption profiles and extraction efficiencies of these toxins (DA, STX) to/from SPATT resins have been extensively studied and verified in the laboratory setting, this knowledge is not applicable to uncontrolled conditions in the field setting, leading to instances of moderate variability in replicate field measurements (coefficients of variation (COV) 15-37%) [32].…”

“…SPATT integrates sampling both spatially and temporally and, in many cases, has been evidenced to be more sensitive than grab sampling methods [31,32]. Although adsorption profiles and extraction efficiencies of these toxins (DA, STX) to/from SPATT resins have been extensively studied and verified in the laboratory setting, this knowledge is not applicable to uncontrolled conditions in the field setting, leading to instances of moderate variability in replicate field measurements (coefficients of variation (COV) 15-37%) [32]. This observed variability in SPATT measurements further supports reliance on grab measurements reported from field studies, where COV for replicate measurements are <10% for ELISA kits (per manufacturer instructions, ABRAXIS, Warminster, PA, USA).…”