Simple and Green Vortex-Assisted Switchable Solvent Liquid Phase Microextraction for the Determination of Indium in Soil with Matrix Matching and Slotted Quartz Tube (SQT) – Flame Atomic Absorption Spectrometry (FAAS)

A novel preconcentration methodology to enhance the sensitivity of a flame atomic absorption spectrometer for indium determination was investigated in this study. The proposed methodology is based on the application of switchable solvent based liquid-phase microextraction combined with a slotted quartz tube. The isolation of indium was performed using N, N-dimethylbenzylamine as the extraction solvent after complexation with (E)-2,4-dibromo-6-(((3-hydroxyphenyl)imino)methyl)phenol. The detection power was enhanced by approximately 169-fold using the developed method with respect to the conventional flame atomic absorption spectrometry system. The quantification and detection limit values were 28.3 and 8.4 ng mL(-1), respectively. The assessment of several interfering ions on the analyte was performed, and spike experiments were used to validate the method's accuracy. Interferences were observed for a ratio of 1:10 analyte:interferent with a value of 27%. The recovery results obtained using matrix matching strategy indicated the applicability of the developed method for soil matrices.