title: Liquid chromatography with electrospray ion-trap mass spectrometry for the determination of yessotoxins in shellfish.
abstract: Yessotoxins are a group of large polyether toxins, produced by marine dinoflagellates, which cause widespread contamination of filter-feeding shellfish. A new, sensitive liquid chromatography-mass spectrometry (LC-MS) method has been developed for the determination of yessotoxin (YTX) and 45-hydroxy-yessotoxin (45-OHYTX), a major metabolite in shellfish. The LC system was coupled, via an electrospray ionisation (ESI) source, to an ion-trap MS in negative mode. The molecular related ion species at m/z 1141 [M-2Na+H]- was used as the parent ion for multiple MS experiments. MS-MS and MS3 gave major fragment ions at m/z 1061 [1141-SO3H]- and m/z 945 [1061-C9H12O]-. Predominant ions, that are due to the fragmentation of the backbone structure of YTXs, were observed at the MS4 stage. Reversed-phase LC using a C16 amide column was preferable to C18 phases for the separation of YTX and 45-OHYTX. Optimum calibration and reproducibility data were obtained for YTX using LC-MS-MS; r 2=0.9960, RSD < or = 6.3% at 0.25 microg YTX/g (n=5). The detection limit (S/N=3) was 30 pg YTX on-column which corresponded to 3 ng/g shellfish tissue.
authors.affiliation: Ecotoxicology Research Unit, Department of Chemistry, Cork Institute of Technology, Bishopstown, Cork, Ireland.
authors.forename: M
authors.initials: M
authors.lastname: Fernández Amandi
authors.forename: A
authors.initials: A
authors.lastname: Furey
authors.forename: M
authors.initials: M
authors.lastname: Lehane
authors.forename: H
authors.initials: H
authors.lastname: Ramstad
authors.forename: K J
authors.initials: KJ
authors.lastname: James
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012758:Shellfish / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*