Determination of BMAA and three alkaloid cyanotoxins in lake water using dansyl chloride derivatization and high-resolution mass spectrometry.
A new analytical method was developed for the detection of alkaloid cyanotoxins in harmful algal blooms. The detection of the nonproteinogenic amino acid β-N-methylamino-L-alanine (BMAA) and two of its conformation isomers, 2,4-diaminobutyric acid (DAB) and N-(2-aminoethyl) glycine (AEG), as well as three alkaloid cyanotoxins, anatoxin-a (ANA-a), cylindrospermopsin (CYN), and saxitoxin (STX), is presented. The use of a chemical derivatization with dansyl chloride (DNS) allows easier separation with reversed phase liquid chromatography. Detection with high-resolution mass spectrometry (HRMS) with the Q-Exactive enables high selectivity with specific fragmentation as well as exact mass detection, reducing considerably the possibilities of isobaric interferences. Previous to analysis, a solid phase extraction (SPE) step is used for purification and preconcentration. After DNS derivatization, samples are submitted to ultra high-performance liquid chromatography coupled with heated electrospray ionisation and the Q-Exactive mass spectrometer (UHPLC-HESI-HRMS). With an internal calibration using isotopically-labeled DAB-D3, the method was validated with good linearity (R (2)  > 0.998), and method limits of detection and quantification (MLD and MLQ) for target compounds ranged from 0.007 to 0.01 μg L(-1) and from 0.02 to 0.04 μg L(-1), respectively. Accuracy and within-day/between-days variation coefficients were below 15%. SPE recovery values ranged between 86 and 103%, and matrix effects recovery values ranged between 75 and 96%. The developed analytical method was successfully validated with 12 different lakes samples, and concentrations were found ranging between 0.009 and 0.3 μg L(-1) except for STX which was not found in any sample.
Department of Chemistry, Université de Montréal, CP 6128 Centre-Ville, Montréal, QC, H3C 3J7, Canada.
Audrey
A
Roy-Lachapelle
Morgan
M
Solliec
Sébastien
S
Sauvé
D000470:Alkaloids / Q000032:analysis*; D000599:Amino Acids, Diamino / Q000032:analysis*; D001427:Bacterial Toxins; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D000458:Cyanobacteria / Q000737:chemistry; D000087522:Cyanobacteria Toxins; D003619:Dansyl Compounds / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods; D005068:Eutrophication; D060106:Lakes / Q000032:analysis* / Q000382:microbiology; D057230:Limit of Detection; D013058:Mass Spectrometry / Q000379:methods*; D012530:Saxitoxin / Q000032:analysis*; D052616:Solid Phase Extraction / Q000379:methods; D014326:Tropanes / Q000032:analysis*; D014498:Uracil / Q000031:analogs & derivatives* / Q000032:analysis; D014877:Water Pollution, Chemical / Q000032:analysis
D000470:Alkaloids; D000599:Amino Acids, Diamino; D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D003619:Dansyl Compounds; D014326:Tropanes; C001824:beta-N-methylamino-L-alanine; C089595:cylindrospermopsin; D012530:Saxitoxin; D014498:Uracil; C509783:anatoxin a; C029038:dansyl chloride