title: Elucidation of matrix effects and performance of solid-phase extraction for LC-MS/MS analysis of β-N-methylamino-L-alanine (BMAA) and 2,4-diaminobutyric acid (DAB) neurotoxins in cyanobacteria.
abstract: A liquid chromatography-mass spectrometry (LC-MS/MS) method using hydrophilic interaction liquid chromatography (HILIC) was developed for the analysis of neurotoxins β-N-methylamino-L-alanine (BMAA) and 2,4-diaminobutyric acid (DAB), using multiple reaction monitoring (MRM) scan mode. Oasis-MCX and Strata-X-C polymeric cation-exchange cartridges were used to clean extracts of cyanobacterial cultures, including two strains of Microcystis aeruginosa and one strain of Nostoc sp. The performance of the solid-phase extraction (SPE) cartridges for BMAA and DAB were evaluated using mixed standards and spiked cyanobacterial extracts, which demonstrated recoveries of BMAA and DAB ranging from 66% to 91%. Matrix effects in LC-MS/MS were evaluated, and while there was no effect on BMAA quantitation, suppression of DAB was found. Full scan (Q1) and enhanced product ion (EPI) monitoring showed that the DAB suppression may be due to closely eluting compounds, including lysine, histidine, arginine and three other compounds with [M + H](+) m/z of 88, 164 and 191. The procedures developed allow the sensitive and effective analysis of trace BMAA and DAB levels in cyanobacteria. While DAB was confirmed to be present, no BMAA was found in the cyanobacterial samples tested in the present study.
authors.affiliation: Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education, Qingdao, 266100, China. lafouc@ouc.edu.cn
authors.forename: Aifeng
authors.initials: A
authors.lastname: Li
authors.forename: Hua
authors.initials: H
authors.lastname: Fan
authors.forename: Feifei
authors.initials: F
authors.lastname: Ma
authors.forename: Pearse
authors.initials: P
authors.lastname: McCarron
authors.forename: Krista
authors.initials: K
authors.lastname: Thomas
authors.forename: Xianghai
authors.initials: X
authors.lastname: Tang
authors.forename: Michael A
authors.initials: MA
authors.lastname: Quilliam
mesh_terms: D000599:Amino Acids, Diamino / Q000032:analysis* / Q000302:isolation & purification; D000613:Aminobutyrates / Q000032:analysis* / Q000302:isolation & purification; D016477:Artifacts; D002853:Chromatography, Liquid / Q000379:methods*; D046508:Culture Techniques; D000087522:Cyanobacteria Toxins; D046931:Microcystis / Q000737:chemistry* / Q000254:growth & development; D009498:Neurotoxins / Q000032:analysis / Q000302:isolation & purification; D046937:Nostoc / Q000737:chemistry* / Q000254:growth & development; D052616:Solid Phase Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry
chemical_list: D000599:Amino Acids, Diamino; D000613:Aminobutyrates; D000087522:Cyanobacteria Toxins; D009498:Neurotoxins; C001824:beta-N-methylamino-L-alanine; C005959:2,4-diaminobutyric acid