Extraction of arsenic species from spiked soils and standard reference materials.
The abilities of various extractants to recover four arsenic species [As(iii), As(v), dimethylarsinic acid (DMA), and monomethylarsonic acid (MMA)] from soils spiked with 20 micro g g(-1) As were investigated. The extractants were water, buffer solutions (citrate and ammonium dihydrogen phosphate), acidic solutions (phosphoric acid and acetic acid), a basic solution (sodium hydroxide) and household chemicals (vinegar and Coca Cola). Gentle shaking at room temperature with each extractant for 24 h gave different recoveries for the different arsenic species. With 0.1 M NaOH solution 46% As(iii), 53% DMA, 100% MMA and 84% As(v) were recovered. A rapid extraction procedure using a sonicator probe has been developed to obtain higher extraction efficiencies. Extracts of arsenic-spiked soil, SRM 2711 Montana soil and SRM 2709 San Joaquin soil were analyzed by HPLC-ICP-MS. In the SRM water extracts, DMA and MMA were identified in addition to inorganic arsenic. The solution detection limits (3s) were 0.1, 0.12, 0.13 and 0.15 ng mL(-1) for As(iii), DMA, MMA and As(v), respectively for HPLC-ICP-MS.
Department of Chemistry, Lederle Graduate Research Tower A 701, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003-9336, USA. tyson@chem.umass.edu
Chethaka
C
Kahakachchi
Peter C
PC
Uden
Julian F
JF
Tyson
D001152:Arsenicals / Q000032:analysis*; D002623:Chemistry Techniques, Analytical / Q000379:methods; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*
D001152:Arsenicals; D012987:Soil; D012989:Soil Pollutants