Methods for the Chemical Analysis of β-N-Methylamino-L-A lanine: What Is Known and What Remains to Be Determined

beta-N-Methylamino-L-alanine (BMAA) is a non-canonical amino acid implicated as a cause for amyotrophic lateral sclerosis/parkinsonism dementia complex and potentially other neurodegenerative diseases. As interest in this molecule has increased, there has been a proliferation of methods along with a plethora of opinions as to the superiority of some methods over others. We analyzed the literature with reference to BMAA and its naturally occurring isomers, N-(2-aminoethyl) glycine (AEG) and 2,4 diaminobutyric acid (DAB). A comparison of methods, results, and critiques reveal that a single method has been approved by the AOAC but several different methods provide comparable BMAA quantification concentrations in similar tissues. We also describe a productive way to move forward as technology improves and changes.