Transformation of diphenylarsinic acid and related compounds in groundwater: production of thiol-containing arsenicals

Abstract

Environmental context. Contamination of groundwater by arsenic compounds used in chemical warfare research is a recently discovered environmental problem in Japan. We report evidence that the arsenic compounds originally present in the groundwater are transforming to thio-arsenic compounds of currently unknown environmental fate.Abstract. During routine analyses of groundwater samples contaminated with diphenylarsinic acid (DPAA) at Kamisu, Ibaraki Prefecture, Japan, we obtained data indicating that unknown arsenic compounds accounted for up to 75 % of the total arsenic in some of the samples. Results from using liquid chromatography in combination with elemental mass spectrometry and tandem molecular mass spectrometry suggested that two of the main unknown peaks were diphenyldithioarsinic acid and methylphenyldithioarsinic acid. These assignments were later confirmed by comparison with chemically synthesised compounds. A potential transformation scheme for DPAA in the environment is proposed based on the derivatives identified in the environmental samples.

Contrasting effects of iron reduction on thionation of diphenylarsinic acid in a biostimulated Acrisol

“…One effective solution to remove DPAA from contaminated soils is biostimulation using indigenous microorganisms that are stimulated by exogenous carbon sources and nutrients, and the main transformation pathway of DPAA involves dephenylation (Maejima et al 2011b), methylation (Arao et al 2009), and thionation (Nakamiya et al 2013). Among these, thionation results in the most effective transformation of DPAA in biostimulated soils (Guan et al 2012) and diphenylthioarsinic acid (DPTAA) was the major metabolite detected after incubation with sulfate and lactate (Hisatomi et al 2013).…”

Simultaneous determination of diphenylarsinic and phenylarsinic acids in amended soils by optimized solvent extraction coupled to HPLC–MS/MS

“…Recently, diphenylarsinic acid (DPAA) and phenylarsinic acid (PAA) have increasingly gained attention due to their occurrence as chemical warfare agents at contaminated sites and their potential to generate public and environmental health concerns Nakamiya et al, 2013;Arao et al, 2009;Ochi et al, 2004). The main source of DPAA and PAA into the environment is aromatic arsenicals (AAs) such as Clark I (diphenylcyanoarsine) and Clark II (diphenychloroarsine), which were widely produced during World Wars I and II as chemical warfare agents.…”