Magnetic ionic liquid-based dispersive liquid-liquid microextraction technique for preconcentration and ultra-trace determination of Cd in honey

FIORENTINI, EMILIANO F.; ESCUDERO, LETICIA B.; WUILLOUD, RODOLFO G.

ANALYTICAL AND BIOANALYTICAL CHEMISTRY

SPRINGER HEIDELBERG

Año: 2018

1618-2642

A simple, highly efficient, batch, and centrifuge-less dispersive liquid-liquid microextraction method based on a magnetic ionicliquid (MIL-DLLME) and electrothermal atomic absorption spectrometry (ETAAS) detection was developed for ultra-trace Cddetermination in honey. Initially, Cd(II) was chelated with ammonium diethyldithiophosphate (DDTP) at pH 0.5 followed by itsextraction with the MIL trihexyl(tetradecyl)phosphonium tetrachloroferrate(III) ([P6,6,6,14]FeCl4) and acetonitrile as dispersant.The MIL phase containing the analyte was separated from the aqueous phase using only a magnet. A back-extraction procedurewas applied to recover Cd from the MIL phase using diluted HNO3 and this solution was directly injected into the graphitefurnace of ETAAS instrument. An extraction efficiency of 93% and a sensitivity enhancement factor of 112 were obtained underoptimal experimental conditions. The detection limit (LOD) was 0.4 ng L−1 Cd, while the relative standard deviation (RSD) was3.8% (at 2 μg L−1 Cd and n = 10), calculated from the peak height of absorbance signals. This work reports the first application ofthe MIL [P6,6,6,14]FeCl4 along with the DLLME technique for the successful determination of Cd at trace levels in different honeysamples.