Stable isotopic characterization of ammonium metavanadate (NH4VO3).

ABSTRACT

This paper describes hydrogen ((2)H/(1)H), nitrogen ((15)N/(14)N), and oxygen ((18)O/(16)O) isotopic characterization of ammonium metavanadate (NH(4)VO(3)), a toxic industrial chemical (TIC). We analyzed nineteen high purity compounds obtained from nine suppliers, which show large ranges in trivariate stable isotope compositions, nearly 100-fold greater than analytical uncertainty. Covariation between δ(2)H and δ(15)N values indicates these ratios can be used to trace ammonia compounds, which are critical for the industrial purification of vanadyl ions and precipitation of ammonium metavanadate crystals. δ(2)H and δ(18)O plot far from the Meteoric Water Line (MWL), and suggest materials and industrial processing may lead to decoupling of H and O isotopes. We show how stable isotope characterization is a valuable forensic tool that discriminates between NH(4)VO(3) samples due to differences in source materials, modes of production, and facility location.