Development of a Hyphenated Method Called DLLME/TLM for Trace Analysis of Cd

Dispersive Liquid-Liquid Microextraction / Thermal Lens Microscopy (DLLME/TLM) was developed as a new combination method for preconcentration and determination of Cd. Thermal Lens Microscopy is suitable for the determination of analyte after DLLME because of the low volume of the remained phase after DLLME and increasing of the enhancement factor for the nonpolar organic solvents. Some effective parameters on the micro extraction, complex formation and combination were selected and optimized. Under optimum conditions, the calibration graphs were linear in the range of 0.05-20 µg/L with the detection limit of 0.008 µg/L. The Relative Standard Deviation (RSD) for 1 and 10 µg/L of cadmium was 3.1 and 2.3, respectively. The enhancement factor of 1200 was obtained from a sample volume of 10.0 mL. DLLME/TLM method was applied to the analysis of real samples. The accuracy of the method was proved by using standard reference materials and micro spectrophotometry.