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Papers by Andy Selwood

Toxicon : official journal of the International Society on Toxinology, Jan 15, 2004

A simple and sensitive in situ method for monitoring the occurrence of toxic algal blooms and she... more A simple and sensitive in situ method for monitoring the occurrence of toxic algal blooms and shellfish contamination events has been developed. The technique involves the passive adsorption of biotoxins onto porous synthetic resin filled sachets (SPATT bags) and their subsequent extraction and analysis. The success of the method is founded on the observation that during algal blooms significant amounts of toxin, including the low polarity lipophilic compounds such as the pectenotoxins and the okadaic acid complex toxins, are dissolved in the seawater. The results of field trials during Dinophysis acuminata and Protoceratium reticulatum blooms are presented. These data prove the concept and demonstrate that the technique provides a means of forecasting shellfish contamination events and predicting the net accumulation of polyether toxins by mussels. As an early warning method it has many advantages over current monitoring techniques such as shellfish-flesh testing and phytoplankton ...

Toxicon : official journal of the International Society on Toxinology, 2002

Toxin profiles were determined in phytoplankton cell concentrates and Greenshell mussels (Perna c... more Toxin profiles were determined in phytoplankton cell concentrates and Greenshell mussels (Perna canaliculus) exposed to a dinoflagellate bloom dominated by Dinophysis acuta and Protoceratium reticulatum. This was achieved by using a method for the simultaneous identification and quantification of a variety of micro-algal toxins by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionisation (+/-) and monitoring of daughter ions in multiple reaction modes. Plankton concentrates and shellfish contained high levels of yessotoxins (YTXs) and pectenotoxins (PTXs) and low levels of okadaic acid (OA). A high proportion (>87%) of the OA in both plankton and shellfish was released by alkaline hydrolysis. An isomer of pectenotoxin 1 (PTX1i) was nearly as abundant as pectenotoxin 2 (PTX2) in the plankton and shellfish, and the latter contained high levels of their respective seco acids. DTX1, DTX2, and PTX6 were not detected. MS-MS experiments revealed that the she...

Toxicon, 2002

Toxin profiles were determined in phytoplankton cell concentrates and Greenshell mussels (Perna c... more Toxin profiles were determined in phytoplankton cell concentrates and Greenshell mussels (Perna canaliculus ) exposed to a dinoflagellate bloom dominated by Dinophysis acuta and Protoceratium reticulatum. This was achieved by using a method for the simultaneous identification and quantification of a variety of micro-algal toxins by liquid chromatography -tandem mass spectrometry (LC -MS/MS) with electrospray ionisation (þ /2 ) and monitoring of daughter ions in multiple reaction modes. Plankton concentrates and shellfish contained high levels of yessotoxins (YTXs) and pectenotoxins (PTXs) and low levels of okadaic acid (OA). A high proportion (. 87%) of the OA in both plankton and shellfish was released by alkaline hydrolysis. An isomer of pectenotoxin 1 (PTX1i) was nearly as abundant as pectenotoxin 2 (PTX2) in the plankton and shellfish, and the latter contained high levels of their respective seco acids. DTX1, DTX2, and PTX6 were not detected. MS-MS experiments revealed that the shellfish contained several other oxygenated metabolites of YTX in addition to 45-hydroxy yessotoxin (45OH-YTX). Gymnodimine (GYM) was present in the shellfish but not plankton and it was probably the residue from a previous GYM contamination event. Unlike the other toxins, GYM was concentrated in tissues outside the digestive gland and levels did not decrease over 5 months. The depuration rates of YTX and PTXs from mussels were modelled. q

Harmful Algae, 2005

The major pectenotoxin and okadaic acid group toxins in Dinophysis acuta and Dinophysis acuminata... more The major pectenotoxin and okadaic acid group toxins in Dinophysis acuta and Dinophysis acuminata cell concentrates, collected from various locations around the coast of the South Island of New Zealand (NZ), were determined by liquid chromatography–tandem mass spectrometry ...

Toxicon : official journal of the International Society on Toxinology, Jan 15, 2004

A simple and sensitive in situ method for monitoring the occurrence of toxic algal blooms and she... more A simple and sensitive in situ method for monitoring the occurrence of toxic algal blooms and shellfish contamination events has been developed. The technique involves the passive adsorption of biotoxins onto porous synthetic resin filled sachets (SPATT bags) and their subsequent extraction and analysis. The success of the method is founded on the observation that during algal blooms significant amounts of toxin, including the low polarity lipophilic compounds such as the pectenotoxins and the okadaic acid complex toxins, are dissolved in the seawater. The results of field trials during Dinophysis acuminata and Protoceratium reticulatum blooms are presented. These data prove the concept and demonstrate that the technique provides a means of forecasting shellfish contamination events and predicting the net accumulation of polyether toxins by mussels. As an early warning method it has many advantages over current monitoring techniques such as shellfish-flesh testing and phytoplankton ...

Toxicon : official journal of the International Society on Toxinology, 2002

Toxin profiles were determined in phytoplankton cell concentrates and Greenshell mussels (Perna c... more Toxin profiles were determined in phytoplankton cell concentrates and Greenshell mussels (Perna canaliculus) exposed to a dinoflagellate bloom dominated by Dinophysis acuta and Protoceratium reticulatum. This was achieved by using a method for the simultaneous identification and quantification of a variety of micro-algal toxins by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionisation (+/-) and monitoring of daughter ions in multiple reaction modes. Plankton concentrates and shellfish contained high levels of yessotoxins (YTXs) and pectenotoxins (PTXs) and low levels of okadaic acid (OA). A high proportion (>87%) of the OA in both plankton and shellfish was released by alkaline hydrolysis. An isomer of pectenotoxin 1 (PTX1i) was nearly as abundant as pectenotoxin 2 (PTX2) in the plankton and shellfish, and the latter contained high levels of their respective seco acids. DTX1, DTX2, and PTX6 were not detected. MS-MS experiments revealed that the she...

Toxicon, 2002

Toxin profiles were determined in phytoplankton cell concentrates and Greenshell mussels (Perna c... more Toxin profiles were determined in phytoplankton cell concentrates and Greenshell mussels (Perna canaliculus ) exposed to a dinoflagellate bloom dominated by Dinophysis acuta and Protoceratium reticulatum. This was achieved by using a method for the simultaneous identification and quantification of a variety of micro-algal toxins by liquid chromatography -tandem mass spectrometry (LC -MS/MS) with electrospray ionisation (þ /2 ) and monitoring of daughter ions in multiple reaction modes. Plankton concentrates and shellfish contained high levels of yessotoxins (YTXs) and pectenotoxins (PTXs) and low levels of okadaic acid (OA). A high proportion (. 87%) of the OA in both plankton and shellfish was released by alkaline hydrolysis. An isomer of pectenotoxin 1 (PTX1i) was nearly as abundant as pectenotoxin 2 (PTX2) in the plankton and shellfish, and the latter contained high levels of their respective seco acids. DTX1, DTX2, and PTX6 were not detected. MS-MS experiments revealed that the shellfish contained several other oxygenated metabolites of YTX in addition to 45-hydroxy yessotoxin (45OH-YTX). Gymnodimine (GYM) was present in the shellfish but not plankton and it was probably the residue from a previous GYM contamination event. Unlike the other toxins, GYM was concentrated in tissues outside the digestive gland and levels did not decrease over 5 months. The depuration rates of YTX and PTXs from mussels were modelled. q

Harmful Algae, 2005

The major pectenotoxin and okadaic acid group toxins in Dinophysis acuta and Dinophysis acuminata... more The major pectenotoxin and okadaic acid group toxins in Dinophysis acuta and Dinophysis acuminata cell concentrates, collected from various locations around the coast of the South Island of New Zealand (NZ), were determined by liquid chromatography–tandem mass spectrometry ...

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