Preconcentration of Total Thallium with a New Dispersive Suspended Droplet Microextraction Method and Its Determination by Flame Atomic Absorption Spectrometry

A fast and centrifuge-less method called dispersive–restoration suspended droplet microextraction was developed for selective determination of trace amounts of Tl(III) by flame atomic absorption spectroscopy. In this method, 8-hydroxy quinoline was used as a complexing agent and toluene was used as an extracting solvent. The effective parameters for determination of Tl(III), such as type of extraction solvent, dispersive time, resting time, magnetic stirrer speed and time, and pH were optimized. Under the optimum conditions, the calibration curve was found to be linear in the range of 8.0-1000 μg l-1 with R2 = 0.997. The percent of relative standard deviation (n = 15), limit of detection, and enrichment factor were 1.4%, 3.1 μg l-1 and 33, respectively. The method was successfully applied for determination of total thallium in real samples including water, nail and hair samples. The good recoveries in the range of 96-103% for real samples confirmed the accuracy and applicability of the present method.