Comparison of analytical tools and biological assays for detection of paralytic shellfish poisoning toxins

Abstract

The paralytic shellfish poisoning toxins (PSTs) were, as their name suggests, discovered as a result of human poisoning after consumption of contaminated shellfish. More recently, however, the same toxins have been found to be produced by freshwater cyanobacteria. These organisms have worldwide distribution and are common in our sources of drinking water, thus presenting another route of potential human exposure. However, the regulatory limits for PSTs in drinking water are considerably lower than in shellfish. This has increased the need to find alternatives to the mouse bioassay, which, apart from being ethically questionable, does not have a limit of detection capable of detecting the PSTs in water at the regulated concentrations. Additionally, the number of naturally occurring PSTs has grown substantially since saxitoxin was first characterised, markedly increasing the analytical challenge of this group of compounds. This paper summarises the development of chromatographic, toxicity, and molecular sensor binding methodologies for detection of the PSTs in shellfish, cyanobacteria, and water contaminated by these toxins. It then summarises the advantages and disadvantages of their use for particular applications. Finally it recommends some future requirements that will contribute to their improvement for these applications.

Year-round algal toxin exposure in free-ranging sea lions

“…Other toxic congers, such as the gonyautoxins, may be more prevalent in the environment than saxitoxin itself, and this limited cross-reactivity could under estimate the actual toxicity of the sample (Turner et al 2014). While HPLC or LC-MS/MS would provide a more extensive toxin profile and the concentrations of other congeners, these analyses for PSTs are costly, time-consuming, and limited to the congeners for which commercial standards are available (Costa et al 2009, Humpage et al 2010. In seawater and shellfish, the Abraxis ELISA detects saxitoxin at lower concentrations compared to traditional methods such as HPLC (Costa et al 2009).…”

Verification and quantification of saxitoxin from algal samples using fast and validated hydrophilic interaction liquid chromatography–tandem mass spectrometry method

“…This technique provides high sensitivity but it is time-consuming, fluorescent matrix compounds can interfere with quantification of other PSP toxins and for routine monitoring purposes it has low daily sample throughput [12]. Besides the LC-FLD methods, enzyme-linked immunosorbent assay (ELISA) and mouse bioassay (MBA) are currently used for monitoring of STX in food supplies and drinking water [13]. The latter methods lack of specificity.…”

An improved sensitive assay for the detection of PSP toxins with neuroblastoma cell-based impedance biosensor

“…The first analytical method permitted by the government in PSP toxins detection is ox-LC-FLD (Humpage et al, 2010). Although this method is sensitive and reliable, it is limited by the expensive reference material and chromophore which needs to produce fluorescent products (Humpage et al, 2010;Turner et al, 2011).…”