Abstract
This paper described a new approach for the preconcentration of lead (Pb2+) by temperature controlled ionic liquid-dispersive liquid phase microextraction (TIL-DLME) prior to analyzing by flame atomic absorption spectrometry (FAAS). An ionic liquid (IL) 1-Butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6] was used as an extractant solvent. The Pb2+ was complexed with ammonium pyrrolidinedithiocarbamate (APDC) and then entered into the infinite IL drops at high temperature (>70°C). Important variables affecting the microextraction efficiency such as pH, ligand concentration, amount of IL, temperature and incubation time were investigated. The results showed that the coexistent ions had no obvious negative effect on the determination of Pb2+. In the optimum experimental conditions, the limit of detection (LOD) and the enhancement factor (EF) were 0.13μgL−1 and 93, respectively. The relative standard deviation (RSD) of 10μgL−1 Pb2+ was 4.3%. The developed method was validated by determining Pb2+ in certified reference material (CRM) and the results showed that the determined values of Pb2+ were in good agreement with the certified value. The proposed method was applied satisfactorily for the preconcentration of Pb2+ in acid digested blood samples of children with different respiratory disorders.
► Trace Pb2+ analysis in blood samples of healthy children and with different respiratory disorders. ► Preconcentration of Pb2+ in acid digested blood samples after chelating with a complexing reagent. ► Using multivariate technique for screening the significant factors influencing TIL-DLME of Pb2+. ► The level of Pb2+ in diseased children was significantly higher than referents of same age group.