Solid Phase Extraction of Arsenic in River Water and Seawater Using a Zirconium (IV) Oxide-Supported Polyamino-Polycarboxylic Acid Type Chelating Resin

Abstract

The solid-phase extraction of arsenic was investigated. Zirconium (IV) oxide-supported polyamino-polycarboxylic acid type chelating resin was used in an attempt to concentrate arsenic. The amount of arsenic (Ⅲ) adsorbed on the resin exceeded 90％ at pH 7.5-8.5, and the amount of arsenic (Ⅴ) adsorbed on the resin exceeded 90％ at pH 2-8.5. The adsorbed arsenic could be eluted using 0.1M sodium hydroxide solution, and was then determined by Electrothermal Atomic Absorption Spectrometry. Adsorption behavior of five different organic arsenic compounds {Monomethylarsonic acid (MMA), Dimethylarsinic acid (DMA), Trimethylarsineoxide (TMAO), Arsenobetaine (AB), Arsenocholine (AC)} were studied with the described method. MMA was well adsorbed. However, other compounds showed low recovery. Decomposition of organic arsenic compounds were examined by photolysis by means of low-pressure mercury lamp. All organic arsenic compounds could be adsorbed on the resin. The proposed method was applicable to the analysis of river water samples and seawater certified reference materials.