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Abstract
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A simple dispersive liquid–liquid microextraction methodology based on the application of 1
hexylpyridinium hexafluorophosphate [HPy][PF6] ionic liquid (IL) as an extractant solvent was proposed
for the preconcentration of trace levels of zinc as a prior step to determination by flame atomic absorption
spectrometry (FAAS). Zinc was complexed with 8-hydroxyquinoline (oxine) and extracted into ionic
liquid. Some effective factors that influence the microextraction efficiency such as pH, oxine concentration,
amount of IL, ionic strength, temperature and centrifugation time were investigated and optimized.
In the optimum experimental conditions, the limit of detection (3 s) and the enhancement factor were
0.22gL−1 and 71, respectively. The relative standard deviation (RSD) for six replicate determinations of
13gL−1 Zn was 1.92%. In order to validate the developed method, a certified reference material (NIST
SRM1549)was analyzed and the determined valueswere in good agreement with the certified values. The
proposedmethod was successfully applied to the trace determination of zinc in water and milk samples.
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