Browsing by Author "Dhanji-Rapkova, Monika"

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    Detection of Tetrodotoxin Shellfish Poisoning (TSP) Toxins and Causative Factors in Bivalve Molluscs from the UK
    (MDPI, 2017-08-30) Turner, Andrew D.; Dhanji-Rapkova, Monika; Coates, Lewis; Bickerstaff, Lesley; Milligan, Steve; O'Neill, Alison; Faulkner, Dermot; McEneny, Hugh; Baker-Austin, Craig; Lees, David N.; Algoet, Myriam
    Tetrodotoxins (TTXs) are traditionally associated with the occurrence of tropical Pufferfish Poisoning. In recent years, however, TTXs have been identified in European bivalve mollusc shellfish, resulting in the need to assess prevalence and risk to shellfish consumers. Following the previous identification of TTXs in shellfish from southern England, this study was designed to assess the wider prevalence of TTXs in shellfish from around the coast of the UK. Samples were collected between 2014 and 2016 and subjected to analysis using HILIC-MS/MS. Results showed the continued presence of toxins in shellfish harvested along the coast of southern England, with the maximum concentration of total TTXs reaching 253 µg/kg. TTX accumulation was detected in Pacific oysters (Crassostrea gigas), native oysters (Ostrea edulis) common mussels (Mytilus edulis) and hard clams (Mercenaria mercenaria), but not found in cockles (Cerastoderma edule), razors (Ensis species) or scallops (Pecten maximus). Whilst the highest concentrations were quantified in samples harvested during the warmer summer months, TTXs were still evident during the winter. An assessment of the potential causative factors did not reveal any links with the phytoplankton species Prorocentrum cordatum, instead highlighting a greater level of risk in areas of shallow, estuarine waters with temperatures above 15 °C
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    Interlaboratory Evaluation of Multiple LC–MS/MS Methods and a Commercial ELISA Method for Determination of Tetrodotoxin in Oysters and Mussels
    (Oxford Univerity Press, 2023-01-06) Turner, Andrew D.; Dean, Karl J.; Dhanji-Rapkova, Monika; Dall’Ara, Sonia; Pino, Florella; McVey, Claire; Haughey, Simon; Logan, Natasha; Elliott, Christopher; Gago-Martinez, Ana; Leao, Jose Manuel; Giraldez, Jorge; Gibbs, Ryan; Thomas, Krista; Perez-Calderon, Ruth; Faulkner, Dermot; McEneny, Hugh; Savar, Veronique; Reveillon, Damien; Hess, Philipp; Arevalo, Fabiola; Lamas, J. Pablo; Cagide, Eva; Alvarez, Mercedes; Antelo, Alvaro; Klijnstra, Mirjam D.; Oplatowska-Stachowiak, Michalina; Kleintjens, Tim; Sajic, Nermin; Boundy, Michael J.; Maskrey, Benjamin H.; Harwood, D. Tim; Gonzalez Jartın, Jesus M.; Alfonso, Amparo; Botana, Luis
    Background Given the recent detection of tetrodotoxin (TTX) in bivalve molluscs but the absence of a full collaborative validation study for TTX determination in a large number of shellfish samples, interlaboratory assessment of method performance was required to better understand current capabilities for accurate and reproducible TTX quantitation using chemical and immunoassay methods. Objective The aim was to conduct an interlaboratory study with multiple laboratories, using results to assess method performance and acceptability of different TTX testing methods. Methods Homogenous and stable mussel and oyster materials were assessed by participants using a range of published and in-house detection methods to determine mean TTX concentrations. Data were used to calculate recoveries, repeatability, and reproducibility, together with participant acceptability z-scores. Results Method performance characteristics were good, showing excellent sensitivity, recovery, and repeatability. Acceptable reproducibility was evidenced by HorRat values for all LC–MS/MS and ELISA methods being less than the 2.0 limit of acceptability. Method differences between the LC–MS/MS participants did not result in statistically different results. Method performance characteristics compared well with previously published single-laboratory validated methods and no statistical difference was found in results returned by ELISA in comparison with LC–MS/MS. Conclusion The results from this study demonstrate that current LC–MS/MS methods and ELISA are on the whole capable of sensitive, accurate, and reproducible TTX quantitation in shellfish. Further work is recommended to expand the number of laboratories testing ELISA and to standardize an LC–MS/MS protocol to further improve interlaboratory precision. Highlights Multiple mass spectrometric methods and a commercial ELISA have been successfully assessed through an interlaboratory study, demonstrating excellent performance.