Effective determination method for a cyanobacterial neurotoxin, β-N-methylamino-l-alanine

We developed a simple and effective analysis procedure that includes pretreatment and determination methods for β-N-methylamino-l-alanine (BMAA), a cyanobacterial neurotoxin. BMAA may be produced by all known groups of cyanobacteria living in freshwater as well as marine environments. In this paper, we report a novel determination method for BMAA. A cation-exchange resin was effective for the selective concentration of BMAA from cyanobacterial extracts and yielded a high recovery rate. Moreover, liquid chromatography (LC)–electrospray ionization mass spectrometry with a hydrophilic LC column was effective for determining BMAA levels. The quantitation limit for BMAA based on selected ion monitoring (SIM) was determined as 0.5 ng at a signal/noise ratio of 5.