Identification of microcystin-RR and [Dha7]microcystin-RR in commercial standards by electrospray ionization mass spectrometry.
Three different commercial standards of microcystin-RR were assessed for purity by the liquid chromatography coupled with electrospray ionization mass spectrometry (LC/ESI/MS) technique. Although the liquid chromatograms with photodiode array detector for each standard looked virtually identical, the analysis of corresponding mass spectra revealed that only one of them contained microcystin-RR per purity assay. The second standard was a mixture of microcystin-RR, and its demethyl variant identified as [Dha7]microcystin-RR, and the third one contained [Dha7]microcystin-RR only. We strongly recommend applying LC coupled with MS for purity assay of microcystin standards.
Health Canada, Safe Environments Programme, Chemistry Research Division, Environmental Health Centre, PL, Tunney's Pasture, Ottawa, Ontario, Canada. Cariton_kubwabo@hc-sc.gc.ca
Cariton
C
Kubwabo
Natalia
N
Vais
Frank M
FM
Benoit
D017033:Anabaena / Q000737:chemistry; D007202:Indicators and Reagents; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic / Q000032:analysis*; D012015:Reference Standards; D021241:Spectrometry, Mass, Electrospray Ionization
C492352:((Dha)7)-microcystin-RR; D007202:Indicators and Reagents; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; C063855:microcystin RR