Development of an Accurate and Sensitive Analytical Method for the Determination of Cadmium at Trace Levels Using Dispersive Liquid-Liquid Microextraction Based on the Solidification of Floating Organic Drops Combined with Slotted Quartz Tube Flame Atomic Absorption Spectrometry.

A dispersive liquid-liquid microextraction (DLLME) technique based on a solidification-of-floating-organic-drop (SFOD) procedure was developed for the determination of trace amounts of cadmium (Cd) by using a flame atomic absorption spectrometer (FAAS) fitted with a slotted quartz tube (SQT). The extraction of Cd was achieved by forming a complex with diphenylcarbazone. Parameters affecting the formation of complex and extraction outputs were carefully optimized to obtain high-absorbance signals to achieve lower LODs. An SQT was fitted on top of the flame burner head to further enhance the absorbance of the signals recorded by the FAAS. Coupling the DLLME-SFOD procedure with SQT-FAAS produced an enhancement factor of about 183. The LOD of the method was 0.23 µg/L with an RSD of 3.8%. Matrix-matching was used to overcome any low recovery results obtained with tap water and municipal wastewater.