Determination of chemical purity and isotopic composition of natural and carbon-13-labeled arsenobetaine bromide standards by quantitativeH-NMR.

Le, Phuong-Mai; Ding, Jianfu; Leek, Donald; Mester, Zoltan; Robertson, Gilles; Windust, Anthony; Meija, Juris

In this study, we report the characterization of three arsenobetaine-certified reference materials by quantitative NMR. We have synthesized an arsenobetaine bromide high-purity standard of natural isotopic composition (ABET-1) and two carbon-13-labeled isotopic standards (BBET-1 and CBET-1). Assignments of the chemical purity and isotopic composition are not trivial in the case of arsenobetaine, and in this study we utilized quantitativeH-NMR techniques for the determination of the mass fractions (chemical purity). The isotopic purity of all three standards was also assessed by NMR from the carbon-13 satellite signals. The standards are non-hygroscopic, high-purity (ca. 0.99 g/g), and the carbon-13 enrichment for both isotopic standards is x(C)≈0.99. These standards are designed for use as primary calibrators for mass spectrometric determination of arsenobetaine in environmental samples.

NATURAL isotopic abundance; NUCLEAR magnetic resonance spectroscopy; BROMIDES; ARSENIC poisoning; TOXICITY testing

Analytical & Bioanalytical Chemistry, 2016, Vol 408, Issue 26, p7413

1618-2642

Academic Journal

10.1007/s00216-016-9827-y