title: Simultaneous quantification of Pacific ciguatoxins in fish blood using liquid chromatography-tandem mass spectrometry.
abstract: Ciguatera fish poisoning (CFP) is a food intoxication caused by exposure to ciguatoxins (CTXs) in coral reef fish. Rapid analytical methods have been developed recently to quantify Pacific-CTX-1 (P-CTX-1) in fish muscle, but it is destructive and can cause harm to valuable live coral reef fish. Also fish muscle extract was complex making CTX quantification challenging. Not only P-CTX-1, but also P-CTX-2 and P-CTX-3 could be present in fish, contributing to ciguatoxicity. Therefore, an analytical method for simultaneous quantification of P-CTX-1, P-CTX-2, and P-CTX-3 in whole blood of marketed coral reef fish using sonication, solid-phase extraction (SPE), and liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed. The optimized method gave acceptable recoveries of P-CTXs (74-103 %) in fish blood. Matrix effects (6-26 %) in blood extracts were found to be significantly reduced compared with those in muscle extracts (suppressed by 34-75 % as reported in other studies), thereby minimizing potential for false negative results. The target P-CTXs were detectable in whole blood from four coral reef fish species collected in a CFP-endemic region. Similar trends in total P-CTX levels and patterns of P-CTX composition profiles in blood and muscle of these fish were observed, suggesting a relationship between blood and muscle levels of P-CTXs. This optimized method provides an essential tool for studies of P-CTX pharmacokinetics and pharmacodynamics in fish, which are needed for establishing the use of fish blood as a reliable sample for the assessment and control of CFP.
authors: State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong SAR, China.
authors: Yim Ling
authors: YL
authors: Mak
authors: Jia Jun
authors: JJ
authors: Wu
authors: Wing Hei
authors: WH
authors: Chan
authors: Margaret B
authors: MB
authors: Murphy
authors: James C W
authors: JC
authors: Lam
authors: Leo L
authors: LL
authors: Chan
authors: Paul K S
authors: PK
authors: Lam
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002922:Ciguatoxins / Q000097:blood / Q000737:chemistry* / Q000302:isolation & purification; D004524:Eels / Q000097:blood*; D013058:Mass Spectrometry / Q000379:methods*; D015394:Molecular Structure; D009132:Muscles / Q000737:chemistry*; D052616:Solid Phase Extraction
chemical_list: D002922:Ciguatoxins