Considerations in As Analysis and Speciation

Abstract

A modified field technique can quantify particulate As, soluble As(III), and soluble As(V) in drinking water. Several problems with commonly used techniques that analyze for arsenic are reported, and solutions are proposed. Analytical techniques can accurately detect \u3c0.5 μg/L total arsenic if certain conditions are met: iron, nitrate, and other interferences are overcome in hydride generation techniques, poor recoveries are overcome in graphite furnace atomic adsorption techniques, and chloride interferences are accounted for in inductively coupled plasma mass spectrometry techniques. Because no techniques adequately preserve arsenic species during storage, a speciation protocol that is fast (about 5 min/sample), relatively inexpensive (about $10/resin column), and user‐friendly and that can be applied in the field was developed. Particulate arsenic represents a significant fraction of total arsenic in drinking water