title: 1H NMR quantification in very dilute toxin solutions: application to anatoxin-a analysis.
abstract: A complete procedure is described for the extraction, detection and quantification of anatoxin-a in biological samples. Anatoxin-a is extracted from biomass by a routine acid base extraction. The extract is analysed by GC-MS, without the need of derivatization, with a detection limit of 0.5 ng. A method was developed for the accurate quantification of anatoxin-a in the standard solution to be used for the calibration of the GC analysis. 1H NMR allowed the accurate quantification of microgram quantities of anatoxin-a. The accurate quantification of compounds in standard solutions is rarely discussed, but for compounds like anatoxin-a (toxins with prices in the range of a million dollar a gram), of which generally only milligram quantities or less are available, this factor in the quantitative analysis is certainly not trivial. The method that was developed can easily be adapted for the accurate quantification of other toxins in very dilute solutions.
authors.affiliation: Laboratório de Biotecnologia, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense, Av. Alberto Lamego 2000, Campos dos Goytacazes, RJ BR-28015-620, Brazil. dagnino@uenf.br
authors.forename: Denise
authors.initials: D
authors.lastname: Dagnino
authors.forename: Jan
authors.initials: J
authors.lastname: Schripsema
mesh_terms: D001427:Bacterial Toxins / Q000032:analysis* / Q000302:isolation & purification*; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D000087522:Cyanobacteria Toxins; D008401:Gas Chromatography-Mass Spectrometry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008387:Marine Toxins / Q000032:analysis* / Q000302:isolation & purification*; D052998:Microcystins; D011522:Protons; D014326:Tropanes
chemical_list: D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D008387:Marine Toxins; D052998:Microcystins; D011522:Protons; D014326:Tropanes; C509783:anatoxin a