Development of effervescence-assisted liquid phase microextraction based on fatty acid for determination of silver and cobalt ions using micro-sampling flame atomic absorption spectrometry

Abstract

In this work, coupling of effervescence-assisted dispersive liquid-liquid microextraction based on a medium-chain fatty acid (EA-DLLME-FA) with accurate micro-sampling flame atomic absorption spectrometric (MS-FAAS) analysis was developed for the first time as a swift, facile, and effective analytical procedure for the satisfactory analysis of Ag+ and Co2+ ions from different real samples. During the microextraction process, 1-phenyl-1,2-propanedione-2-oximethiosemicarbazone (PPDOT) was used as a proper chelating agent to form hydrophobic complex compounds, causing easy and effective penetration of metal ions into the organic extraction phase. On the other hand, by providing proper pH values via addition of an efficacious effervescent agent, the extraction medium could acquire a dual hydrophilicity/hydrophobicity nature, leading to a simple and efficient proceeding of the foresaid microextraction, followed by a quick and no labor intensive collection of the organic solvent (upper phase) in a special home-made extraction cell. Also simple, rapid, accurate, efficient, and inexpensive analyses via the MS-FAAS technique distinguished the determination of the foresaid metal ions. Under other optimum conditions enriched via the central composite design, the studied ions could be accurately determined in the wide linear dynamic ranges of 5.0–150ngmL−1 and 8.0–200ngmL−1 for the Ag+ and Co2+ ions, respectively, with the determination coefficients (R2s) higher than 0.98. The low limits of detection and the good percentage relative standard deviations were found to be in the span of 2.0–3.0ngmL−1 and 3.4–4.2%, respectively. The percentage extraction recoveries and the enrichment factors were found to be reasonably quantitative. These valuable results indicated the high quality of the developed procedure for the influential quantification of the aforementioned metal ions from cow milk, vitamin B12, orange juice, and tap water.