Abstract
Determination of lead by electrothermal atomic absorption spectrometry using ionic liquid single drop microextraction
Author(s): Saeid NazariA simple and efficientmethod for rapid extraction and determination of the trace levels of lead was developed by single dropmicroextraction combined with electrothermal atomic absorption spectrometry detection. 1-phenyl-3- methyl-4-benzoyl-5-pyrazolone (PMBP) was used as both extractant and chemical modifier and ionic liquid, 1- butyl- 4- methylpyridinium trifluoromethylsulfonate [BMPy][TfO] as the extraction solvent. Lead was complexed with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) and extracted into a 4µL ionic liquid drop. The extracted complex was directly injected into the graphite furnace. Several factors that influence the microextraction efficiency, such as type and volume of organic solvent, pH, concentration of chelating agent, extraction time, stirring rate and effect of salt were investigated and the optimized microextraction conditions were established. Under the optimum conditions, the enrichment factor and recoverywere 465 and 93%, respectively. The calibration graph was linear in the range of 0.02- 1 µg L-1with correlation coefficient of 0.9987 under the optimum conditions of the recommended procedure. The detection limit based on the 3Sb criterion was 0.008 µg L-1 and relative standard deviation for (RSD) for ten replicatemeasurement of 0.1 µg L-1and 0.3 µg L-1 leadwas 4.2 and 3.5%respectively. The characteristic concentration was 0.007 µg L-1 equivalent to a characteristicmass of 28 pg. The results for determination of lead in referencematerials local tapwater, river and wellwater demonstrated the accuracy, recovery and applicability of the presented method.
