EVALUATION OF COLUMN CHROMATOGRAPHY AND FLAMELESS ATOMIC-ABSORPTION SPECTROPHOTOMETRY FOR ARSENIC SPECIATION AS APPLIED TO AQUATIC SYSTEMS

Flameless atomic absorption (FAA) and chromatographic methods for routine analysis and speciation of environmental arsenic are presented. Matrix modification with Ni(NO3)2 was used with FAA to measure As concentrations in river water and sediment samples. Detection limits were 2 ng of As/L and FAA response for As concentration was independent of As species. Inorganic As [As(V) and As(III)], monomethylarsonic acid (MMAA), and dimethylarsinic acid (DMAA) were separated on cation exchange columns and detected by FAA. These methods were applied to samples collected from the Menominee River, Wis., where As contamination has resulted in As levels ranging from 1 to 1000 /ig/L in river water, from 10 to 7000 mg/L in sediment pore water, and from 4 to 30 mg/g in sediment solids. Field data are presented to illustrate the application of the procedures. Sampling methods and preparation are included. © 1979, American Chemical Society. All rights reserved.