Mass spectrometry (MS) is a powerful technique for analyzing biotoxins1 because of its high selectivity, its high dynamic linear range and its ability to quantify many potent hepatotoxins—including microcystins and nodularins in natural blooms, cyanobacterial strains, fish and other biological samples—in a single analysis run.2-3
A phenomenon called eutrophication promotes the natural occurrence of harmful cyanobacterial blooms in freshwater and marine ecosystems.4 These blooms produce toxic metabolites that have diverse structural and physicochemical properties. Frequently detected cyanotoxins include microcystins, nodularins, cylindrospermopsin and neurotoxins, which increasingly threaten the ecosystem and human health.5 While these blooms of toxic cyanobacteria species are present in various surface water sources, the primary route of exposure for most people is through drinking water, which can result in consumption advisories from regulatory authorities.6-8
For example, the World Health Organization (WHO) provisional guideline for microcystin-LR (MC-LR) is a limit of 1 μg/L.9 The US Environmental Protection Agency (EPA) 10-day drinking water health advisory for MC-LR is a limit of 0.3 μg/L for infants and children up to 6 years old, and 1.6 μg/L for adults.10 In Canada, the maximum acceptable concentration (MAC) of MC-LR is 1.5 μg/L.11
Traditionally, surface waters have been analyzed for these toxins using high-performance liquid chromatography (HPLC) with ultra-violet (UV) detection or other methodologies such as gas chromatography (GC). However, these approaches have limitations, especially when it comes to potential cross-contamination, which could lead to a high risk of false positives.
A shift to mass spectrometry for detecting biotoxins
With the diversity in chemical structures of natural toxins in the environment, liquid chromatography-tandem mass spectrometry (LC-MS/MS) is an ideal tool for the comprehensive analysis of a wide scope of toxins, including microcystins, in a single analysis.
Using LC-MS/MS enables:
Enhanced sensitivity for lower-level toxin detection
Better performance by simplifying sample preparation and enabling a faster time to results
Improved ruggedness to accommodate diverse sample types
Higher specificity for the improved accuracy and reliability of results
To learn more about SCIEX solutions for mycotoxin and natural toxin detection in food and feed, click here.
Flores, C.; Caixach, J. An integrated strategy for rapid and accurate determination of free and cell-bound microcystins and related peptides in natural blooms by liquid chromatography–electrospray-high resolution mass spectrometry and matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry using both positive and negative ionization modes. Journal of Chromatography A 2015, 1407, 76–89. doi: 10.1016/j.chroma.2015.06.022
Cameán, A.; Moreno, I. M.; Ruiz, M. J.; Picó, Y. Determination of microcystins in natural blooms and cyanobacterial strain cultures by matrix solid-phase dispersion and liquid chromatography-mass spectrometry. Analytical and Bioanalytical Chemistry 2004, 380(3), 537–544. doi: 10.1007/s00216-004-2755-2
Moreno, I. M.; Molina, R.; Jos, A.; Picó, Y.; Cameán, A. M. Determination of microcystins in fish by solvent extraction and liquid chromatography. Journal of Chromatography A 2005, 1080(2), 199–203. doi: 10.1016/j.chroma.2005.05.029
Corbel, S.; Mougin, C.; Bouaïcha, N. Cyanobacterial toxins: Modes of actions, fate in aquatic and soil ecosystems, phytotoxicity and bioaccumulation in agricultural crops. Chemosphere 2014, 96, 1–15. doi: 10.1016/j.chemosphere.2013.07.056
Buratti, F. M.; Manganelli, M.; Vichi, S.; Stefanelli, M.; Scardala, S.; Testai, E.; Funari, E. Cyanotoxins: Producing organisms, occurrence, toxicity, mechanism of action and human health toxicological risk evaluation. Archives of Toxicology 2017, 91(3), 1049–1130. doi: 10.1007/s00204-016-1913-6
Makarewicz, J. C.; Boyer, G. L.; Lewis, T. W.; Guenther, W.; Atkindson, J.; Arnold, M. Spatial and temporal distribution of the cyanotoxin microcystin-LR in the Lake Ontario ecosystem: Coastal embayments, rivers, nearshore and offshore, and upland lakes. J. Great Lakes Res. 2009, 35, 83–89. doi: 10.1016/j.jglr.2008.11.010