Abstract
A novel and effective analytical method was developed for the determination of trace cobalt by slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) after simultaneous dispersive liquid-liquid microextraction (S-DLLME) based on contemporaneous complexation and extraction. Approximately 48 times enhancement in detection power was recorded based on the comparison of detection limits of the developed system (4.7 ng/mL) with the detection power of the conventional FAAS. Percent relative standard deviation for the lowest concentration was calculated as 3.8%. Spiked recovery experiments on chamomile tea extract samples were carried out to determine applicability of the developed method to real sample matrix. Percent recovery results for two different concentrations were approximately 100%, with standard deviation values below 10%. This graphical abstract shows the procedure of the developed S-DLLME-SQT-FAAS method. The extraction solvent was dispersed with the aid of ligand solution into the aqueous cobalt solution to allow for simultaneous complexation. Sedimental phase was collected and organic phase was evaporated at ≈70 °C. Concentrated HNO3 was added to dissolve the residue before absorbance measurement in a FAAS system.