Liquid chromatographic determination of the cyanobacterial toxin beta-n-methylamino-L-alanine in algae food supplements, freshwater fish, and bottled water.
Beta-N-Methylamino-L-alanine (BMAA) is a neurotoxin originally found in cycad seeds and now known to be produced by many species of freshwater and marine cyanobacteria. We developed a method for its determination in blue-green algae (BGA) food supplements, freshwater fish, and bottled water by using a strong cation-exchange, solid-phase extraction column for cleanup after 0.3 M trichloroacetic acid extraction of BGA supplements and fish. Bottled water was applied directly onto the solid-phase extraction column. For analysis of carbonated water, sonication and pH adjustment to 1.5 were needed. To determine protein-bound BMAA, the protein pellet left after extraction of the BGA supplement and fish was hydrolyzed by boiling with 6 M hydrochloric acid; BMAA was cleaned up on a C18 column and a strong cation-exchange, solid-phase extraction column. Determination of BMAA was by liquid chromatography of the fluorescent derivative formed with 9-fluorenylmethyl chloroformate. The method was validated by recovery experiments using spiking levels of 1.0 to 10 microg/g for BGA supplements, 0.5 to 5.0 microg/g for fish, and 0.002 microg/g for bottled water; mean recoveries were in the range of 67 to 89% for BGA supplements and fish, and 59 to 92% for bottled water. Recoveries of BMAA from spiked extracts of hydrolyzed protein from BGA supplements and fish ranged from 66 to 83%. The cleanup developed provides a useful method for surveying foods and supplements for BMAA and protein-bound BMAA.
Scott
Peter M
PM
Bureau of Chemical Safety, Health Canada, Banting Building, AL: 2203D, Ottawa, Ontario K1A 0K9, Canada. peter_scott@hc-sc.gc.ca
Niedzwiadek
Barbara
B
Rawn
Dorothea F K
DF
Lau
Ben P-Y
BP
D000599:Amino Acids, Diamino / Q000032:analysis*; D000818:Animals; D002853:Chromatography, Liquid; D000458:Cyanobacteria / Q000737:chemistry*; D000087522:Cyanobacteria Toxins; D019587:Dietary Supplements / Q000032:analysis; D005399:Fishes / Q000378:metabolism; D005453:Fluorescence; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D017747:Seafood / Q000032:analysis; D012680:Sensitivity and Specificity; D014867:Water / Q000737:chemistry
D000599:Amino Acids, Diamino; D000087522:Cyanobacteria Toxins; D014867:Water; C001824:beta-N-methylamino-L-alanine