Determination Of Lipophilic Toxins Research Articles

A Year of Bio-Monitoring (2021): Presence of Algae of the Genus Alexandrium, Dinophysis, Prorocentrum and Non-Compliance for Paralytic Toxins and Lipophilic Toxins in Bivalve Mollusks Bred in Sardinia (W Mediterranean Sea)

Bivalve mollusk production represents the principal aquaculture activity in Sardinia (40°03′ N, 9°05′ E). In 2021, 859 water samples and 1270 mollusk samples were analyzed. The species Alexandrium minutum caused the accumulation of Paralytic Shellfish Toxins (PST) in three samples of bivalve mollusks. Dinophysis acuminata complex caused the accumulation of lipophilic toxins (LTs) belonging to the okadaic acid group (OAs) in 18 samples of bivalve mollusks. The research of paralytic shellfish toxins (PSTs) in shellfish samples has been carried out with LC-FLD, as mentioned in the AOAC 2005 Official Method 2005.06. The determination of LTs was carried out by LC-MS/MS analysis. DTX2, belonging to the group of OA toxins, was detected for the first time in Sardinia, in mussels sampled in Tortolì. The presence of Dinophysis and Prorocentrum species was correlated with the accumulation of the OA toxin group in bivalve mollusks, showing a certain repeatability at certain times of the year in the areas included in the study. The results of the present study can help to plan and organize more effective bio-monitoring sampling strategies.

Development of a High Performance Liquid Chromatography-Tandem Mass Spectrometry Method for Determination of Lipophilic Toxins in Marine Shellfishes and Edible Safety Evaluation

Abstract At present, edible marine shellfishes are often contaminated by a combination of different kinds of marine lipophilic toxins. In this study, several common lipophilic shellfish toxins (LSTs) in marine shellfishes were simultaneously detected by liquid chromatography-tandem mass spectrometry, and the safety risk of commercial marine shellfishes was evaluated based on the materiome of LSTs. Under the optimal conditions, the developed method displayed satisfactory recovery values (63.2%–88.8%), precision (relative standard deviations ≤ 14.5%), and sensitivity (limit of detection in the range of 0.54–2.69 ng g−1) for all analytes. Among the 105 commercially available shellfish samples, 42.86% of the samples had at least one kind of toxins. The highest average content was 47.60 μg kg−1 of DTX1, which was the most serious contaminant in marine shellfish samples. Total Exposure Risk Index (∑ERI) was calculated based on Total Daily Intake (TDI) and Acute Reference Dose (ARfD) of each toxin to evaluate the safety risk of commercial marine shellfishes. The results indicated that the risk of toxin poisoning was 19.05% in the commercial available marine shellfishes, and the scallops (Chlamys farreri) have the highest poisoning risk among different shellfishes used in this study. In summary, a new method based on the combined contamination of LSTs was successfully developed for the risk assessment of commercial marine shellfishes. The proposed method is stricter than that in the relevant rules of European Food Safety Authority (EFSA) and can benefit to protect shellfish consumers from poisoning risk.

Determination of Lipophilic Toxins by LC/MS/MS: Single-Laboratory Validation

An LC/MS/MS method has been developed, assessed, and intralaboratory-validated for the analysis of the lipophilic toxins currently regulated by European Union legislation: okadaic acid (OA) and dinophysistoxins 1 and 2, including their ester forms; azaspiracids 1, 2, and 3; pectenotoxins 1 and 2; yessotoxin (YTX), and the analogs 45 OH-YTX, Homo YTX, and 45 OH-Homo YTX; as well as for the analysis of 13-desmetil-spirolide C. The method consists of duplicate sample extraction with methanol and direct analysis of the crude extract without further cleanup or concentration. Ester forms of OA and dinophysistoxins are detected as the parent ions after alkaline hydrolysis of the extract. The validation process of this method was performed using both fortified and naturally contaminated samples, and experiments were designed according to International Organization for Standardization, International Union of Pure and Applied Chemistry, and AOAC guidelines. With the exception of YTX in fortified samples, RSDr below 15% and RSDR were below 25%. Recovery values were between 77 and 95%, and LOQs were below 60 microg/kg. These data together with validation experiments for recovery, selectivity, robustness, traceability, and linearity, as well as uncertainty calculations, are presented in this paper.