Trace determination of nickel in Thymus serpyllum L. (wild thyme) tea with a matrix matching strategy by UV-Vis spectrometry after vortex-assisted DES/DPC-based microextraction

In our study, an environmentally friendly, simple, and novel analysis method was developed for the pre- concentration of nickel in Thymus serpyllum L. (wild thyme) tea samples before their analysis by UV-Vis spectroscopy. Deep eutectic solvent (DES)/1,5 Diphenylcarbazone (DPC) was used as the ligand solution in preconcentration and liquid-liquid microextraction (LLME) was applied. At the beginning of our study, parameters that could increase the extraction efficiency were optimized. Our method's detection and quantification limit values were calculated as 0.0002 mg/L and 0.0006 mg/L. A linear region was observed in the range of 0.0005-0.1 mg/L and the percent relative standard deviation (%RSD) was found to be 0.33. Matrix matching strategy was applied in percentage recovery studies. Percentage recovery values were found in the range of 91 %-116 %.