A conventional SI system was used to construct an ingenious combination of graphite furnace (GF) AA detector, with microminiaturized solvent extraction concept, that somewhat resembles Heyrovskys hanging drop mercury electrode.
The micro-drop of di-isobutyl\ ketone (DIBK) (60 µL) is suspended at a glass capillary tip within the flow through micro extraction cell. The sample solution flows around the suspended droplet, while the analyte is being extracted into the organic phase. At the end of the extraction cycle the droplet is retracted, transferred via multiposition valve into the transfer loop (L) and from there, after a valve switch, further transported by air into a graphite furnace (GF).
Single Drop Micro-Extraction
2.3.33.
A model system based on complexation of cadmium with ammonium diethyldithiophosphate (REAGENT) and following extraction into DIBK, was used to validate this novel approach, which eliminates the troublesome components of traditional SE systems (segmentor and separator). The method uses submilliliter volumes of organic solvent per assay and demonstrates feasibility of equilibriation of 15mL of aqueous sample solution with a miniscule volume (60 µL) of organic phase. While this is indisputably an extraordinary achievement, the extraction efficiency and robustness of the setup should be carefully considered.
Anthemidis, A.N. and Adam, I.S.I. (2009) Anal. Chim. Acta, 632: 216220.
