title: 1H NMR determination of beta-N-methylamino-L-alanine (L-BMAA) in environmental and biological samples.
abstract: A nuclear magnetic resonance (1H NMR) method for the determination of beta-N-methylamino-L-alanine (L-BMAA) in environmental aqueous samples was developed and validated. L-BMAA is a neurotoxic modified amino acid that can be produced by cyanobacteria in aqueous environments. This toxin was extracted from samples by means of solid-phase extraction (SPE) and identified and quantified by 1H NMR without further derivatization steps. The lower limit of quantification (LLOQ) was 5 microg/mL. Good inter and intra-assay precision was also observed (relative standard deviation <8.5%) with the use of 4-nitro-DL-phenylalanine as an internal standard (IS). This method of 1H NMR analysis is not time consuming and can be readily utilized to monitor L-BMAA and confirm its presence in environmental and biological samples.
authors.affiliation: Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, USP, Av. Professor Lineu Prestes, 580 813B CEP: 05508-900 São Paulo, SP, Brazil.
authors.forename: Sidnei
authors.initials: S
authors.lastname: Moura
authors.forename: Mariah de Almeida
authors.initials: Mde A
authors.lastname: Ultramari
authors.forename: Daniela Mendes Louzada
authors.initials: DM
authors.lastname: de Paula
authors.forename: Mauricio
authors.initials: M
authors.lastname: Yonamine
authors.forename: Ernani
authors.initials: E
authors.lastname: Pinto
mesh_terms: D000599:Amino Acids, Diamino / Q000032:analysis* / Q000737:chemistry; D000087522:Cyanobacteria Toxins; D003903:Deuterium; D004784:Environmental Monitoring / Q000379:methods*; D009498:Neurotoxins / Q000032:analysis* / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular; D015203:Reproducibility of Results; D014867:Water / Q000737:chemistry*
chemical_list: D000599:Amino Acids, Diamino; D000087522:Cyanobacteria Toxins; D009498:Neurotoxins; D014867:Water; C001824:beta-N-methylamino-L-alanine; D003903:Deuterium