Rapid automated total arsenic and arsenic speciation by inductively coupled plasma mass spectrometry

Abstract

This work focuses on providing fast and reliable separations of arsenobetaine (AsB), trimethylarsine oxide (TMAO), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), arsenocholine (AsC), arsenite (As(III)), and arsenate (As(V)). Two different methods are presented: (1) a one-column method for the determination of AsB, DMA, MMA, AsC, As(III), and As(V) with a separation time of ∼2 minutes and (2) a two-column method for the determination of AsB, TMAO, DMA, MMA, AsC, As(III), and As(V) with a separation time of ∼4.5 minutes. Recovery of the two methods falls between 94 and 107%. Methods were evaluated for accuracy by analyzing proficiency samples from Centre de Toxicologie du Québec (CTQ) and New York Department of Health (NYDOH). Correlation between the measured values and reference values was very good, with a <4.5% difference in results. Limits of detection in a urine matrix ranged from 2.8–6.0 ng L⁻¹ As and 4.1–9.1 ng L⁻¹ As for the one- and two-column methods, respectively.