A new method for the speciation of arsenic species in water, seafood and cigarette samples using an eggshell membrane

Abstract

This work is based on the application of the eggshell membrane (ESM) of fresh chicken as a sorbent in a solid phase extraction procedure for arsenic speciation with detection by electrothermal atomic absorption spectrometry. The ESM can adsorb several heavy metal ions from a dilute aqueous solution with high affinity and short contact time, depending on pH and ionic characteristics. It thusly becomes a promising candidate as a solid adsorbent in extraction systems. The procedure is based on the solid phase extraction of the complex formed by As(III) with ammonium pyrrolidine dithiocarbamate (APDC). Solutions of As(III) were percolated through the eggshell membrane-filled minicolumn (ESM). Then, the analyte contained in the sorbent was desorbed by a 4.0 mol L−1 HNO3/ethanol solution (2:3). The influence of variables such as eluent, sample volume, pH effect, APDC volume, eluent volume, atomization, pyrolysis temperature, and sample flow was studied. Under optimized conditions, the method presented a limit of detection and enrichment factor of 0.01 μg L−1 and 17, respectively. Arsenic speciation was also tested because As(V) does not react with APDC, but is retained by ESM. Thus, the determination of total arsenic and As(V) allows the determination of both species. The procedure was applied to the determination of arsenic species in water, seafood, and cigarette samples.