Development of a reversed-phase dispersive liquid–liquid microextraction method for the extraction and preconcentration of lead and cadmium ions in some cosmetic products

In present study, a reversed-phase dispersive liquid–liquid microextraction method followed by flame atomic absorption spectrometry as a low cost, easy operation, high sensitivity, and accuracy analytical approach has been developed for the analysis of lead(II) and cadmium(II) ions in cosmetic samples. For this purpose, the samples were diluted by toluene and then a mixture of diluted nitric acid solution and acetonitrile was used as the extraction solvent and disperser solvent, respectively. Effect of some important parameters on efficiency of the method was investigated to reach high enrichment factors. Under optimum experimental conditions, the calibration curves were linear in the ranges of 10.0–200 and 1.0–175 μg Kg −1 for lead(II) and cadmium(II), respectively. Moreover, relative standard deviations of the developed procedure for intra- ( n = 6) and inter-day ( n = 4) precisions were in the ranges of 3.4–6.5% ( C = 20 μg Kg −1 of each cation). Eventually, the suggested method was successfully used in analysis of the chosen ions in various cosmetic brands.