Determination of the neurotoxins BMAA (β-N-methylamino-L-alanine) and DAB (α-,γ-diaminobutyric acid) by LC-MSMS in Dutch urban waters with cyanobacterial blooms

Abstract

We aimed to determine concentrations of the neurotoxic amino acids β-N-methylamino-L-alanine (BMAA) and α-,γ-diaminobutyric acid (DAB) in mixed species scum material from Dutch urban waters that suffer from cyanobacterial blooms. BMAA and DAB were analysed in scum material without derivatization by LC-MSMS (liquid chromatography coupled to tandem mass spectrometry) using hydrophilic interaction chromatography (HILIC). Our method showed high selectivity, good recovery of added compounds after sample extraction (86% for BMAA and 85% for DAB), acceptable recovery after sample hydrolysation (70% for BMAA and 56% for DAB) and acceptable precision. BMAA and DAB could be detected at an injected amount of 0.34 pmol. Free BMAA was detected in nine of the 21 sampled locations with a maximum concentration of 42 μg/g DW. Free DAB was detected in two locations with a maximum concentration of 4 μg/g DW. No protein-associated forms were detected. This study is the first to detect underivatized BMAA in cyanobacterial scum material using LC-MSMS. Ubiquity of BMAA in cyanobacteria scums of Dutch urban waters could not be confirmed, where BMAA and DAB concentrations were relatively low; however, co-occurrence with other cyanobacterial neurotoxins might pose a serious health risk including chronic effects from low-level doses.

Key words::

• BMAA
• cyanobacteria
• cyanotoxins
• DAB
• LC-MSMS

Acknowledgements

We thank Wendy Beekman for assistance in sample preparation. EF was supported by a grant from The Netherlands Organization for Scientific Research (NWO). This study was supported by the Ministry of Transport, Public Works and Water Management, Directorate-General for Public Works and Water Management, Centre for Water Management.

Declaration of interest: The authors declare that there are no conflicts of interest.