Trace mercury determination in drinking and natural water samples by room temperature ionic liquid based-preconcentration and flow injection-cold vapor atomic absorption spectrometry

ESTEFANÍA M. MARTINISA, PAULA BERTÓNA, ROBERTO A. OLSINAC, JORGELINA C. ALTAMIRANOA,B, RODOLFO G.WUILLOUDA,B,∗

JOURNAL OF HAZARDOUS MATERIALS.

ELSEVIER SCIENCE BV

Año: 2009 vol. 167 p. 475 - 481

0304-3894

A liquid–liquid extraction procedure (L–L) based on room temperature ionic liquid (RTIL) was developedfor the preconcentration and determination of mercury in differentwater samples. The analytewasquantitatively extracted with 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]) underthe form of Hg-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Hg-5-Br-PADAP) complex. A volumeof 500l of 9.0 mol L−1 hydrochloric acid was used to back-extract the analyte from the RTIL phase intoan aqueous media prior to its analysis by flow injection-cold vapor atomic absorption spectrometry (FICV-AAS). A preconcentration factor of 36 was achieved upon preconcentration of 20mL of sample. Thelimit of detection (LOD) obtained under the optimal conditions was 2.3 ng L−1 and the relative standarddeviation (RSD) for 10 replicates at 1gL−1 Hg2+ was 2.8%, calculated with peaks height. The methodwassuccessfully applied to the determination of mercury in river, sea, mineral and tap water samples and acertified reference material (CRM).© 2009 Elsevier B.