title: Validation of an accelerated solvent extraction liquid chromatography-tandem mass spectrometry method for Pacific ciguatoxin-1 in fish flesh and comparison with the mouse neuroblastoma assay.
abstract: Ciguatera fish poisoning (CFP) is a global foodborne illness caused by consumption of seafood containing ciguatoxins (CTXs) originating from dinoflagellates such as Gambierdiscus toxicus. P-CTX-1 has been suggested to be the most toxic CTX, causing ciguatera at 0.1 μg/kg in the flesh of carnivorous fish. CTXs are structurally complex and difficult to quantify, but there is a need for analytical methods for CFP toxins in coral reef fishes to protect human health. In this paper, we describe a sensitive and rapid extraction method using accelerated solvent extraction combined with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for the detection and quantification of P-CTX-1 in fish flesh. By the use of a more sensitive MS system (5500 QTRAP), the validated method has a limit of quantification (LOQ) of 0.01 μg/kg, linearity correlation coefficients above 0.99 for both solvent- and matrix-based standard solutions as well as matrix spike recoveries ranging from 49% to 85% in 17 coral reef fish species. Compared with previous methods, this method has better overall recovery, extraction efficiency and LOQ. Fish flesh from 12 blue-spotted groupers (Cephalopholis argus) was assessed for the presence of CTXs using HPLC-MS/MS analysis and the commonly used mouse neuroblastoma assay, and the results of the two methods were strongly correlated. This method is capable of detecting low concentrations of P-CTX-1 in fish at levels that are relevant to human health, making it suitable for monitoring of suspected ciguateric fish both in the environment and in the marketplace.
authors.affiliation: State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong SAR, China.
authors.forename: Jia Jun
authors.initials: JJ
authors.lastname: Wu
authors.forename: Yim Ling
authors.initials: YL
authors.lastname: Mak
authors.forename: Margaret B
authors.initials: MB
authors.lastname: Murphy
authors.forename: James C W
authors.initials: JC
authors.lastname: Lam
authors.forename: Wing Hei
authors.initials: WH
authors.lastname: Chan
authors.forename: Mingfu
authors.initials: M
authors.lastname: Wang
authors.forename: Leo L
authors.initials: LL
authors.lastname: Chan
authors.forename: Paul K S
authors.initials: PK
authors.lastname: Lam
mesh_terms: D000818:Animals; D001492:Bass / Q000378:metabolism; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002922:Ciguatoxins / Q000302:isolation & purification*; D005399:Fishes / Q000378:metabolism*; D006801:Humans; D057230:Limit of Detection; D051379:Mice; D017747:Seafood / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D002922:Ciguatoxins