Department of Chemistry
Library of the School of Science

2021-07-29

2021

Manolidi Korina

Αντώνιος Καλοκαιρινός, Καθηγητής, Τμήμα Χημείας, ΕΚΠΑ
Δρ. Αναστασία Χισκιά, Ερευνήτρια Α’, ΕΚΕΦΕ «Δημόκριτος»
Αναστάσιος Οικονόμου, Καθηγητής, Τμήμα Χημείας, ΕΚΠΑ,
Δρ. Θεόδωρος Τριάντης, Ερευνητής Β’, ΕΚΕΦΕ «Δημόκριτος»
Νικόλαος Θωμαΐδης, Καθηγητής, Τμήμα Χημείας, ΕΚΠΑ
Νικόλαος Λυδάκης-Σημαντήρης, Καθηγητής, Τμήμα Γεωπονίας, Ελληνικό Μεσογειακό Πανεπιστήμιο, Κρήτη
Κόκκινος Χρήστος, Επίκουρος Καθηγητής, Τμήμα Χημείας, ΕΚΠΑ

Development of analytical methods for the determination of cyanotoxins in water, plant and animal tissues using liquid chromatography coupled to tandem mass spectrometry

English

Development of analytical methods for the determination of cyanotoxins in water, plant and animal tissues using liquid chromatography coupled to tandem mass spectrometry

Cyanobacteria are globally distributed photosynthetic microorganisms, also cultivated to be used as dietary supplements, which under favorable conditions can release a wide range of hazardous compounds, called cyanotoxins. BMAA and its structural isomers, DAB, AEG and BAMA, are non-proteinogenic amino acids (AAs) that have been associated with neurodegenerative diseases and belong to toxic cyanobacterial metabolites. Paralytic Shellfish Poisoning toxins (PSPs), are potent neurotoxins, considered to present the highest acute toxicity among cyanotoxins. Possible routes to human exposure to cyanotoxins is the consumption of contaminated drinking water and food supplements or seafood; however, guidance values do not exist for either group of all types of exposure routes, with some exceptions for PSPs. Determination of cyanotoxins in biological samples is a challenging task due to the low molecular weight of polar BMAA, present as free or bound to proteins at low concentrations, possibly co-occurring with its isomers; while diverse chemical properties of polar PSPs, make their isolation from water problematic. In this doctoral dissertation, sensitive analytical workflows have been developed for the accurate determination of different fractions of BMAA, DAB, AEG and BAMA, as well as nine PSPs (STX, NeoSTX, dc-STX, GTX1,2,3,4 and dc-GTX2,3), in aquatic and cyanobacterial samples, as well as plant and animal tissues. D3-BMAA and D3-DAB were used as internal standards for analytical quality assurance. Simultaneous preconcentration of PSPs was performed using a dual SPE cartridge assembly inducing cation exchange mechanisms. Efficient chromatographic separation was achieved using a HILIC column, while detection and quantification was achieved using a triple quadrupole mass spectrometer in positive ESI mode and multiple reaction monitoring. Validation of the methods was successful with high recoveries, up to 80-100% for most of the compounds, %RSD values below 15% and LODs as low as 1.0-4.6 ng L-1 for aquatic samples and 0.1-2.6 μg g-1 for cyanobacteria, plant and animal tissues. The optimum analytical workflow was successfully applied to cyanobacterial samples and strain cultures collected from 17 Greek Lakes, as well as cyanobacteria-based food supplements, invertebrates and plant tissues including a cycad seed. The unambiguous identification of target cyanotoxins in a number of samples will grow awareness for the significant threat posed on human health, while regular monitoring of dietary products will be promoted, as well as the development of guidelines for cyanotoxins.

Science

BMAA, PSPs, Dual SPE, Extraction, HILIC-MS/MS, Cyanobacteria, Dietary Supplements, Shellfish.

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https://pergamos.lib.uoa.gr/uoa/dl/object/2958877