12th International Conference on Harmful Algae

INTERNATIONAL SOCIETY FOR THE STUDY OF HARMFUL ALGAE12 th <strong>International</strong> <strong>Conference</strong> on Harmful Algae, Copenhagen, Denmark, 4-8 September 2006provides a high degree of selectivityand sensitivity for the determinationof paralytic shellfish poisoning(PSP) toxins (Dell'Aversano et al.,2005). At Fisheries ResearchServices, a HILIC LC-MS methodfor the detection of PSP toxins(STX, NEO, dcSTX, GTX1 to GTX4,dcGTX2 and dcGTX3) has beendeveloped using a singlequadrupole LC-MS for the detectionof these toxins in UK shellfish.Calibration range and linearity wereacceptable (0.5 to 5 µM, R2 > 0.99)and a detection limit of ~0.5 µM wasachieved. Unfortunately, sensitivitywas at least ten times lessfavourable when compared withvalidated high performance-liquidchromatography with fluorescencedetection (HPLC-FLD), which canbe prone to interference fromendogenous fluorescent matrixcompounds. In order to increasesensitivity of the LC-MS, we arecurrently developing methods forimproved sample preparation, usingsolid phase extraction (SPE) andwe will present our preliminaryfindings.Dell'Aversano et al. / J. Chromatogr.A (2005) 190-201O.07-05Anatoxin contamination offreshwater resources in NewZealandSession: O.07 - Toxin analysis 1Presentation time: 12:20 - 12:40PT Holland 1 , AI Selwood 1 , SA Wood 1 ,K Smith 1 , P McNabb 1 , P Rasmussen 21 Cawthron Institute, NELSON, NewZealand2 Australian Water Quality Centre,BOLIVAR, SA, AustraliaCyanobacterial blooms in NewZealand water resources have beensurveyed and, in response to strictnew standards for drinking water,more intensive monitoring forcyanotoxins has been initiated. Afilamentous bloom-formingcyanobacterium from a lake hasbeen shown to be a potent producerof anatoxin-a. Phylogenetic analysisof the 16S rRNA and rpoB genesequences classified the organismas Aphanizomenon issatschenkoi.Benthic samples of Oscillatoria sp.and Phormidium sp. from severalrivers were shown to produceanatoxin-a and homoanatoxin-a,and were conclusively associatedwith illness and death of dogs.These findings are the firstconfirmed reporting of anatoxinproducingspecies in the SouthernHemisphere and the first report ofanatoxin-a production by A.issatschenkoi. An isolate of thelatter was brought into culture and,during LC-MS assays for anatoxin-aproduction, an unstable biosyntheticprecursor was found in freshsamples of the culture.Characterisation of the precursor isdescribed and implications foraccurate analysis of anatoxin-a inwater samples are discussed. TheNew Zealand Drinking WaterStandards (2005) includeprovisional maximum allowablevalues (PMAVs) for anatoxin-a,homoanatoxin-a,cylindrospermopsin andmicrocystins of 6, 2, 1 and 1 µg/Lrespectively. The validation ofsuitable test methods to enforcethese low limits is presented.O.07-06The Biosense ASP ELISA - anearly warning tool for theenvironmental monitoring ofdomoic acid in phytoplanktonand seawaterSession: O.07 - Toxin analysis 143