Determination of microcystins, nodularin, anatoxin-a, cylindrospermopsin, and saxitoxin in water and fish tissue using isotope dilution liquid chromatography tandem mass spectrometry

• Published in: Journal of Chromatography A Vol. 1599; pp. 66 - 74
• Main Authors: Haddad, Samuel P., Bobbitt, Jonathan M., Taylor, Raegyn B., Lovin, Lea M., Conkle, Jeremy L., Chambliss, C. Kevin, Brooks, Bryan W.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 16.08.2019
• Subjects: Food safety; Harmful algal bloom; HILIC; Nontarget analysis; RPLC; Water quality; Nontarget analysis; Harmful algal bloom; Food safety; RPLC; HILIC; Water quality
• DOI: 10.1016/j.chroma.2019.03.066
• ISSN: 0021-9673

•Optimized extraction and separation of cyanotoxins for water and fish tissue.•Novel use of a zwitterionic hydrophilic interaction liquid chromatography column.•Novel characterization of matrix effects using isotopically labeled standards.•Targeted and nontargeted analyses using the same extraction and separation methods.•Novel data mining techniques for use with nontargeted screening. Cyanobacteria can form dense blooms under specific environmental conditions, and some species produce secondary metabolites known as cyanotoxins, which present significant risks to public health and the environment. Identifying toxins produced by cyanobacteria present in surface water and fish is critical to ensuring high quality food and water for consumption, and protectionn of recreational uses. Current analytical screening methods typically focus on one class of cyanotoxins in a single matrix and rarely include saxitoxin. Thus, a cross-class screening method for microcystins, nodularin, anatoxin-a, cylindrospermopsin, and saxitoxin was developed to examine target analytes in environmental water and fish tissue. This was done, due to the broad range of cyanotoxin physicochemical properties, by pairing two extraction and separation techniques to improve isolation and detection. For the first time a zwitterionic hydrophilic interaction liquid chromatography column was evaluated to separate anatoxin-a, cylindrospermopsin, and saxitoxin, demonstrating greater sensitivity for all three compounds over previous techniques. Further, the method for microcystins, nodularin, anatoxin-a, and cylindrospermopsin were validated using isotopically labeled internal standards, again for the first time, resulting in improved compensation for recovery bias and matrix suppression. Optimized extractions for water and fish tissue can be extended to other congeners in the future. These improved separation and isotope dilution techniques are a launching point for more complex, non-targeted analyses, with preliminary targeted screening.