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These two research projects aim to develop better detection methods for the routine biotoxin monitoring program for shellfish.
<p>The consumption of shellfish that have accumulated marine biotoxins produced by some naturally occurring planktonic algae can cause human illness.
<p>There are three main types of shellfish toxins, giving rise to amnesic, diarrhetic and paralytic shellfish poisoning (ASP, DSP and PSP).
<p>Competent Authorities within the EU are required to monitor for the presence of these toxins to protect public health.
<p>This project compared two liquid chromatography mass spectrometry methods (LC-MS and LC-MS-MS) with conventional high-performance liquid chromatography (HPLC) and their application in the routine biotoxin monitoring program.
The developing technique of LC-MS has become increasingly reliable and affordable in recent years. In this research, two LC-MS methods were investigated, single quadrupole and tandem LC-MS.
<p>Both techniques initially separate mixtures into individual group of compounds using a chromatographic column and then measure the masses of these compounds.
<p>In addition, when voltages are applied within the instrument the separated compounds fragment and the resulting ions can also be measured.
<p>The pattern of fragmentation can be very distinctive for a given compound and this allows unrivalled specificity in the identification of that compound.
<p>This is the principle of single quadrupole LC-MS. There is also tandem LC-MS or LC-MS-MS, which uses the same principle as LC-MS but has an additional MS stage that is used initially to separate compound before initial or further fragmentation.
<p>LC-MS-MS reduces interference and the signal to noise ratio makes it more sensitive than LC-MS. These techniques have been used extensively during research into shellfish toxins (ASP and DSP) and are becoming increasingly used by EU member states as monitoring tools.
<p>The Laboratory of the Government Chemist (LGC) developed a LC-MS-MS method for the analysis of ASP, DSP and PSP toxins and both LGC and FRS undertook the validation of these methods (ASP and DSP toxins only).
<p>Validation required the determination of limits of detection (LOD), limits of quantification (LOQ), linear response and spiked recoveries for the shellfish matrices of interest (scallop gonad, adductor muscle, remainder and whole scallop, whole mussel) using certified standards and reference material.
<p>Once validation was complete, FRS made an assessment of the stability of both the ASP and DSP toxins in tissue homogenates and extracts to determine their maximum storage period prior to method comparison.
<p>To compare the LC-MS methods, tissue homogenates and extracts were sent from FRS to LGC and analysed simultaneously for the matrices of interest. In addition, where appropriate, samples were analysed by established HPLC techniques at FRS.
<p>The evaluation of LC-MS and LC-MS-MS methods for the detection of PSP was undertaken in the latter stages of the projects.
<p>Find more about this project and other FSA food safety-related projects at the <a href="http://www.food.gov.uk/science/research/" target="_blank">Food Standards Agency Research webpage</a>.