A novel integrated strategy for the detection and quantification of the neurotoxin beta-N-methylamino-l-alanine in environmental samples

作者：Beri Joshua; Kirkwood Kaylie I; Muddiman David C; Bereman Michael S^*

来源：Analytical and Bioanalytical Chemistry, 2018, 410(10): 2597-2605.

DOI：10.1007/s00216-018-0930-0

• BMAA
• CZE
• Isomer separation
• Quantification
• HRAM MS/MS
• Seafood

We describe a set of new tools for the detection and quantification of beta-N-methylamino-l-alanine (BMAA) which includes a novel stable isotope-labeled BMAA standard (C-13(3),N-15(2)) and a chip-based capillary electrophoresis mass spectrometry platform for separation and detection. Baseline resolution of BMAA from its potentially confounding structural isomers N-2-aminoethylglycine (AEG) and 2,4-diaminobutyric acid (2,4-DAB) is achieved using the chip-based CE-MS system in less than 1 min. Detection and linearity of response are demonstrated across > 3.5 orders of dynamic range using parallel reaction monitoring (PRM). The lower limit of detection and quantification were calculated for BMAA detection at 40 nM (4.8 ng/mL) and 400 nM (48 ng/mL), respectively. Finally, the strategy was applied to detect BMAA in seafood samples purchased at a local market in Raleigh, NC where their harvest location was known. BMAA was detected in a sea scallop sample. Because the BMAA/stable isotope-labeled C-13(3),N-15(2)-BMAA (SIL-BMAA) ratio in the scallop sample was below the limit of quantification, a semiquantitative analysis of BMAA content was carried out, and BMAA content was estimated to be approximately 820 ng BMAA/1 g of wet scallop tissue. Identification was verified by high mass measurement accuracy of precursor (< 5 ppm) and product ions (< 10 ppm), comigration with SIL-BMAA spike-in standard, and conservation of ion abundance ratios for product ions between BMAA and SIL-BMAA. Interestingly, BMAA was not identified in the free protein fraction but only detected after protein hydrolysis which suggests that BMAA is tightly bound by and/or incorporated into proteins.

• 出版日期2018-4