title: Liquid Chromatography with a Fluorimetric Detection Method for Analysis of Paralytic Shellfish Toxins and Tetrodotoxin Based on a Porous Graphitic Carbon Column.
abstract: Paralytic shellfish toxins (PST) traditionally have been analyzed by liquid chromatography with either pre- or post-column derivatization and always with a silica-based stationary phase. This technique resulted in different methods that need more than one run to analyze the toxins. Furthermore, tetrodotoxin (TTX) was recently found in bivalves of northward locations in Europe due to climate change, so it is important to analyze it along with PST because their signs of toxicity are similar in the bioassay. The methods described here detail a new approach to eliminate different runs, by using a new porous graphitic carbon stationary phase. Firstly we describe the separation of 13 PST that belong to different groups, taking into account the side-chains of substituents, in one single run of less than 30 min with good reproducibility. The method was assayed in four shellfish matrices: mussel (Mytillus galloprovincialis), clam (Pecten maximus), scallop (Ruditapes decussatus) and oyster (Ostrea edulis). The results for all of the parameters studied are provided, and the detection limits for the majority of toxins were improved with regard to previous liquid chromatography methods: the lowest values were those for decarbamoyl-gonyautoxin 2 (dcGTX2) and gonyautoxin 2 (GTX2) in mussel (0.0001 mg saxitoxin (STX)·diHCl kg(-1) for each toxin), decarbamoyl-saxitoxin (dcSTX) in clam (0.0003 mg STX·diHCl kg(-1)), N-sulfocarbamoyl-gonyautoxins 2 and 3 (C1 and C2) in scallop (0.0001 mg STX·diHCl kg(-1) for each toxin) and dcSTX (0.0003 mg STX·diHCl kg(-1) ) in oyster; gonyautoxin 2 (GTX2) showed the highest limit of detection in oyster (0.0366 mg STX·diHCl kg(-1)). Secondly, we propose a modification of the method for the simultaneous analysis of PST and TTX, with some minor changes in the solvent gradient, although the detection limit for TTX does not allow its use nowadays for regulatory purposes.
authors.affiliation: Department Analytical Chemistry, Faculty of Sciences, University of Santiago de Compostela, Lugo 27002, Spain. veronica.rey@rai.usc.es.
authors.forename: Veronica
authors.initials: V
authors.lastname: Rey
authors.affiliation: Department Analytical Chemistry, Faculty of Sciences, University of Santiago de Compostela, Lugo 27002, Spain. anamaria.botana@usc.es.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Botana
authors.affiliation: CIFGA S.A., Plaza Santo Domingo 20-5ª, Lugo 27001, Spain. mercedes@cifga.es.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Alvarez
authors.affiliation: CIFGA S.A., Plaza Santo Domingo 20-5ª, Lugo 27001, Spain. alvaro@cifga.es.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Antelo
authors.affiliation: Department Pharmacology, Veterinary Faculty, University of Santiago de Compostela, Lugo 27002, Spain. luis.botana@usc.es.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Botana
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation* / Q000592:standards; D005470:Fluorometry / Q000592:standards; D005506:Food Contamination; D006108:Graphite / Q000737:chemistry*; D057230:Limit of Detection; D049878:Mytilus / Q000737:chemistry; D049895:Ostrea / Q000737:chemistry; D010084:Oxidation-Reduction; D010243:Paralysis / Q000139:chemically induced*; D049910:Pecten / Q000737:chemistry; D049897:Pectinidae / Q000737:chemistry; D016062:Porosity; D015203:Reproducibility of Results; D012530:Saxitoxin / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000032:analysis; D017747:Seafood / Q000009:adverse effects / Q000032:analysis*; D057096:Shellfish Poisoning; D013779:Tetrodotoxin / Q000009:adverse effects / Q000032:analysis*
chemical_list: D012530:Saxitoxin; D013779:Tetrodotoxin; C013007:gonyautoxins; D006108:Graphite
keywords: paralytic shellfish toxins; porous graphitic carbon; post-column oxidation liquid chromatography; shellfish matrices; tetrodotoxin