Trace determination of manganese(II) by temperature-controlled/assisted ionic liquid-based dispersive liquid-phase microextraction and electrothermal atomic absorption spectrometry

A microextraction method, namely temperature-controlled/assisted ionic liquid-based dispersive liquid-phase microextraction (DLPME) for manganese(II) determination in environmental water samples is presented. Manganese(II) was extracted from aqueous solution into an ionic liquid (IL) after complexation with 1-(2-thiazolylazo)-2-naphthol (TAN) and directly introduced for electrothermal atomic absorption spectrometry (ETAAS) determination. Several factors that might affect ETAAS signal and extraction efficiency, such as pyrolysis and atomization temperature; and pH adjustment, concentration of TAN, extraction time, volume of IL and stirring rate were studied. Within optimal experimental conditions, the detection limit (3σ), the quantification limit (10σ), the enrichment factor and the relative standard deviation for five replicate determinations at 0.5 μg L−1 of manganese(II) were calculated as 0.023 μg L−1, 0.076 μg L−1, 58.7 and 6.3 %, respectively. The presented method was also successfully applied to the determination of manganese(II) in real samples. The main benefits of the method are simplicity, low cost, rapidity, high recovery, powerful extraction efficiency and the proposed approach is free of volatile organic solvents.