Ultrasound-Assisted Emulsification Solidified Floating Organic Drop Microextraction for the Determination of Trace Cadmium in Water Samples by Flame Atomic Absorption Spectrometry

A liquid-phase microextraction technique was developed using ultrasound-assisted emulsification solidified floating organic drop microextraction (USAE-SFODME) combined with flame atomic absorption spectrometry (FAAS) for the extraction and determination of trace cadmium in water samples. Microextraction efficiency factors, such as extraction solvent type and extraction volume, time, temperature, pH, the amount of the chelating agent, and salt effect, were investigated and optimized. Under optimum conditions, an enrichment factor of 81.0 was obtained for 6.0 mL of water sample. The calibration graph was linear in the range of 10-450 mu g L-1 with a detection limit of 0.66 mu g L-1. The relative standard deviations (RSD) for ten replicate measurements of 20 and 300 mu g L-1 of Cd were 3.34% and 2.42%, respectively. The accuracy of the proposed method was assessed either by determination of Cd in a certified reference material of water or by addition-recovery experiments.