title: Arsenic speciation in rice and soil containing related compounds of chemical warfare agents.
abstract: Diphenylarsinic acid, phenylarsonic acid, methylphenylarsinic acid (MPAA), dimethylphenylarsine oxide (DMPAO), and methyldiphenylarsine oxide (MDPAO) in soil and rice were extracted, separated by reversed-phase chromatography, and quantified by ICPMS with a membrane desolvating system. For the extraction of arsenicals from rice grain and straw, 68% HNO3 provided better extraction efficiency than water, 50% methanol, or 2.0 mol L(-1) trifluoroacetic acid. For the extraction from soil, 68% HNO3 provided better extraction efficiency than H2O, 1 mol L(-1) H3PO4, or 1 mol L(-1) NaOH. The contaminated soil contained all five aromatic arsenicals along with inorganic arsenicals as main species (5.86 +/- 0.19 microg of As kg(-1): 60.8 +/- 2.0% of total extracted As). After pot experiments, rice straw contained mainly DMPAO (7.71 +/- 0.48 microg of As kg(-1): 60.5 +/- 3.7%), MDPAO (0.91 +/- 0.07 microg of As kg(-1): 7.2 +/- 0.5%), and inorganic As (2.85 +/- 0.20 microg of As kg(-1): 22.3 +/- 1.6%). On the other hand, rice grain contained mainly MPAA (1.17 +/- 0.04 microg of As kg(-1): 86.7 +/- 2.7%). The root uptake of each species from the soil and transport from straw to grains were significantly related to the calculated log K(ow) values.
authors.affiliation: National Institute for Agro-Environmental Sciences, Tsukuba, Ibaraki 305-8604, Japan. kojibaba@affrc.go.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Baba
authors.forename: Tomohito
authors.initials: T
authors.lastname: Arao
authors.forename: Yuji
authors.initials: Y
authors.lastname: Maejima
authors.forename: Eiki
authors.initials: E
authors.lastname: Watanabe
authors.forename: Heesoo
authors.initials: H
authors.lastname: Eun
authors.forename: Masumi
authors.initials: M
authors.lastname: Ishizaka