Flame Atomic Absorption Spectroscopy Combined with a New Univariate Strategy for Optimization of Cd(II) Preconcentration Procedure: Salicylideneaniline as Complexation-Agent-Based Traditional Dispersive Liquid-Liquid Microextraction

Abstract

A procedure based on dispersive liquid-liquid microextraction (DLLME) for cadmium (Cd) quantification in an Iraqi environmental matrix by flame atomic absorption spectroscopy (FAAS) was applied in this work. A case study approach was chosen to obtain further in-depth information on the Cd levels and to evaluate the effectiveness of N-salicylideneaniline (SAN) as a complexing agent for preconcentration and extraction of Cd. Univariate strategy was utilized for achieving the optimum extraction conditions: 75.0 μL of carbon tetrachloride as the extraction solvent, 10 mL of a sample solution adjusted the pH at 8.50 containing 0.8% (w/v) SAN, and 1400 μL of methanol as the dispersive solvent, within 30 s complexation time. The estimated limits of detection (LOD) and quantification (LOQ) under optimum conditions were 0.26 and 0.87 μg/L, respectively. Enrichment factors were obtained in two manners, found to be 24.4 and 44.3. To evaluate the accuracy of the method, known amounts of analytes were spiked and compared with the results achieved using microwave digestion/graphite furnace atomic absorption spectrometer (MWD/GF-AAS) for solid samples, and direct graphite furnace atomic absorption spectrometer (GF-AAS) for water samples. Procedure was applied for analyzing eight environmental samples, the Cd levels for water samples ranged from 3.01 to 7.33 μg/L with a relative standard deviation (4.1–10.4 RSD%), while the concentration for the solid sample (Mentha piperita) was 2.71 μg/g (RSD% = 7.4). DLLME/FAAS proposed procedure is eff ective, simple, and has the benefi t of minimizing the organic solvent consumption, by a few microliters, which results in little waste.