title: Flame atomic absorption determination of trace amounts of cadmium after preconcentration using a thiol-containing task-specific ionic liquid.
abstract: Dispersive liquid-liquid microextraction (DLLME) based on a task-specific ionic liquid (TSIL) was developed for the extraction and preconcentration of trace amounts of cadmium from aqueous samples, followed by flame atomic absorption spectrometry (FAAS) determination. In the proposed approach, cadmium ions are extracted from aqueous samples using small volumes of trioctylmethylammonium thiosalicylate (TOMATS) dissolved in acetone. TOMATS is a thiol-containing TSIL that can form metal thiolate complexes due to the chelating effect of the ortho-positioned carboxylate group relative to the thiol functionality. The main parameters affecting the performance of DLLME based on TSIL, such as pH, amount of TOMATS, extraction time, injection volume, salt addition, and centrifugation time, were optimized. Under optimum conditions, an LOD of 1.16 ng/mL and a good RSD of 1.8% at 60.0 ng/mL were obtained (n=7). The proposed method was applied to tap water, wastewater, well water, and milk samples. The results showed that DLLME based on TSIL combined with FAAS is a rapid, simple, sensitive, selective, low cost, volatile organic solvent-free, and efficient analytical method for the separation and determination of trace amounts of cadmium ions.
authors.affiliation: Shahid Bahonar University of Kerman, Department of Chemistry, PO Box 76175-133, Kerman, Iran. m.mohamadi794@gmail.com
authors.forename: Maryam
authors.initials: M
authors.lastname: Mohamadi
authors.forename: Ali
authors.initials: A
authors.lastname: Mostafavi
mesh_terms: D000880:Anthraquinones; D002104:Cadmium / Q000737:chemistry*; D004785:Environmental Pollutants / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D052578:Ionic Liquids / Q000737:chemistry*; D007477:Ions; D015394:Molecular Structure; D012492:Salts; D013054:Spectrophotometry, Atomic / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013997:Time Factors
chemical_list: D000880:Anthraquinones; D004785:Environmental Pollutants; D052578:Ionic Liquids; D007477:Ions; D012492:Salts; D013438:Sulfhydryl Compounds; D002104:Cadmium; C036239:cyanine green G base