title: Analysis of Natural Toxins by Liquid Chromatography-Chemiluminescence Nitrogen Detection and Application to the Preparation of Certified Reference Materials.
abstract: The implementation of instrumental analytical methods such as LC-MS for routine monitoring of toxins requires the availability of accurate calibration standards. This is a challenge because many toxins are rare, expensive, dangerous to handle, and/or unstable, and simple gravimetric procedures are not reliable for establishing accurate concentrations in solution. NMR has served as one method of qualitative and quantitative characterization of toxin calibration solution Certified Reference Materials (CRMs). LC with chemiluminescence N detection (LC-CLND) was selected as a complementary method for comprehensive characterization of CRMs because it provides a molar response to N. Here we report on our investigation of LC-CLND as a method suitable for quantitative analysis of nitrogenous toxins. It was demonstrated that a wide range of toxins could be analyzed quantitatively by LC-CLND. Furthermore, equimolar responses among diverse structures were established and it was shown that a single high-purity standard such as caffeine could be used for instrument calibration. The limit of detection was approximately 0.6 ng N. Measurement of several of Canada's National Research Council toxin CRMs with caffeine as the calibrant showed precision averaging 2% RSD and accuracy ranging from 97 to 102%. Application of LC-CLND to the production of calibration solution CRMs and the establishment of traceability of measurement results are presented.
authors.affiliation: National Research Council Canada, Measurement Science and Standards, Biotoxin Metrology, 1411 Oxford St, Halifax, NS, Canada B3H 3Z1.
authors.forename: Krista
authors.initials: K
authors.lastname: Thomas
authors.affiliation: National Research Council Canada, Measurement Science and Standards, Biotoxin Metrology, 1411 Oxford St, Halifax, NS, Canada B3H 3Z1.
authors.forename: Dominik
authors.initials: D
authors.lastname: Wechsler
authors.affiliation: National Research Council Canada, Measurement Science and Standards, Biotoxin Metrology, 1411 Oxford St, Halifax, NS, Canada B3H 3Z1.
authors.forename: Yi-Min
authors.initials: YM
authors.lastname: Chen
authors.affiliation: National Research Council Canada, Measurement Science and Standards, Biotoxin Metrology, 1411 Oxford St, Halifax, NS, Canada B3H 3Z1.
authors.forename: Sheila
authors.initials: S
authors.lastname: Crain
authors.affiliation: National Research Council Canada, Measurement Science and Standards, Biotoxin Metrology, 1411 Oxford St, Halifax, NS, Canada B3H 3Z1.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Quilliam
mesh_terms: D002853:Chromatography, Liquid / Q000592:standards; D049449:Luminescence; D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D013058:Mass Spectrometry / Q000592:standards; D008968:Molecular Conformation; D009584:Nitrogen / Q000737:chemistry*; D012015:Reference Standards; D014118:Toxins, Biological / Q000032:analysis*
chemical_list: D014118:Toxins, Biological; D009584:Nitrogen