Extraction of Ultra Trace Amounts Bismuth in Water Samples Using Cloud Point Extraction with 2-Amino-Cyclopentene-1-Dithiocarboxylic Acid

Abstract

A new approach for a cloud point extraction-electrothermal atomic absorption spectrometric method
was used for determining bismuth. The aqueous analyte was acidified with sulfuric acid (pH 3.0–3.5). Triton X-
114 was added as a surfactant and 2-amino-cyclopentene-1-dithiocarboxylic acid was used as a complexing
agent. After phase separation at 50 ◦C based on the cloud point separation of the mixture, the surfactant-rich
phasen was diluted using tetrahydrofuran (THF). Twenty microliters (20 μL) of the enriched solution and 10 μl
of 0.1% (w/v) Pd (NO3)2 as chemical modifier were dispersed into the graphite tube and the analyte was
determined by electrothermal atomic absorption spectrometry. After optimizing extraction conditions and
instrumental parameters, a preconcentration factor of 195 was obtained for a sample of only 10 mL. The
detection limit was 0.04 ng ml−1 and the analytical curve was linear for the concentration range of 0.04–0.70 ng
mL−1. Relative standard deviations were <5%. The method was successfully applied for the extraction and
determination of bismuth in water samples.