Magnetic ionic liquid based microextraction and preconcentration technique for Arsenic speciation analysis by electrothermal atomic absorption spectrometry

MARIA N. OVIEDO; EMILIANO F. FIORENTINI; RODOLFO G. WUILLOUD

Simposio; 15th Rio Symposium on Atomic Spectrometry; 2019

LABORATORIO DE QUIMICA ANALITICA PARA INVESTIGACION Y DESARROLLO ; FACULTAD DE CIENCIAS EXACTAS Y NATURALES ; UNIVERSIDAD NACIONAL DE CUYO

In the present work, a novel LLME technique using the MIL trihexyl(tetradecyl)phosphonium hexachlorodisprosiate ([P6,6,6,14]3DyCl6) (MIL1) was developed for selective separation of As(III) with ammonium pyrollidine dithiocarbamate (APDC) as complexing agent. Then, the extraction and preconcentration of As(V) present in the aqueous phase was performed using the MIL trihexyl(tetradecyl)phosphonium tetrachloroferrate ([P6,6,6,14]FeCl4) (MIL2) by electrothermal atomic absorption spectrometry (ETAAS). This method consists in adjusting the acidity of aqueous samples to a concentration of 1 mol L -1 HCl, followed by the extraction of As(V) with the MIL2. After the vortex stage, the MIL2 was collected with the use of a magnetic rod, diluted in CHCl3 and an aliquot of the eluate was injected into the graphite furnace of ETAAS for As determination. Under optimal experimental conditions, an extraction efficiency of 92% was obtained, an LOD of 15 ng L-1 of As(V) and a relative standard deviation (RSD) of 3.6% (for a As(V) solution of 100 µg L-1 and n = 10). The proposed methodology was successfully applied to aqueous samples.