NCCOS scientists have optimized their previous solid-phase extraction methods in conjunction with liquid chromatography-mass spectrometry to improve the sensitivity of domoic acid determination in seawater and phytoplankton cells and to accommodate fluid and tissue samples from living and dead marine mammals.
Having a reproducible method with high sensitivity for toxin detection is important. Sample types are highly variable and each comes with factors that can interfere with accurate analysis by liquid chromatography-mass spectrometry. Seawater samples have large amounts of salt. Blood, urine, tissue, and fecal samples have salts, biological macromolecules from living or dead marine mammals, and degradation products from dead animals. Interfering components in samples can contaminate analytical instruments and impair the sensitivity to detect toxin. The optimized solid-phase extraction method allowed for removing of interfering components and ability to detect lower concentrations of toxins.
HABs often produce toxins that are detrimental to the health of marine animals and humans. Forecasting and monitoring algal blooms as well as confirming toxin exposure are critical to protect humans and protected species such as dolphins, whales and seals.
The development of these methods for analyzing seawater and marine animal samples helps NOAA meet its mandates to monitor and forecast harmful algal blooms and protect marine mammals.
These methods are published in the February 2012 issue of Analytica Chimica Acta.