Plastic sieve equipped two-syringe assisted magnetic colloidal gel for dispersive solid-phase extraction of manganese in tea samples

In this study, a simple and effective analytical method was described for the determination of manganese in a spectrometric system. For this purpose, a plastic sieve fitted between two syringes was used as a dispersive solid phase extraction tool. The extraction of manganese was performed by using a magnetic colloidal gel (MCG), which was formed by mixing cobalt magnetic nanoparticle (Co-MNP) and deep eutectic solvent. All experimental parameters of the method including Co-MNP amount in MCG, MCG volume, cycle number for pressurized mixing in the two-syringe system and eluent type/volume in the desorption step were carefully evaluated in order to find the best experimental conditions for efficient extraction/preconcentration of manganese. The detection limit was calculated as 4.0 ng/mL for manganese extracted by 150 mu L of MCG from 8.0 mL of aqueous solution at pH 10 with 8 cycles of pressurized mixing. In order to validate the applicability and the accuracy of the developed system, the optimum conditions were applied to jasmine tea samples. The tea samples were analyzed using the standard addition method and the manganese the manganese content were found in the range of 133 - 245 ng/mL. The obtained results showed that the developed method is applicable, accurate and feasible for the determination of manganese at trace levels.