Preconcentration and Separation of Mn(II) from Eenvironmental Water Samples on N,N-bis (Salicylidene) Cyclohexanediamine Functionalized Amberlite XAD-4 Resin and Its Spectrophotometric Assessment

Abstract

A new and sensitive preconcentration procedure was developed for the determination of trace amount of Mn(II) in environmental water samples. Amberlite XAD-4 resin was functionalized with N,N-bis(salicylidene)cyclohexanediamine (SCHD) to preconcentrate and separate Mn(II) at the trace level concentrations. Mn(II) ion in environmental water samples was determined by the formaldoxime spectrophotometric method. The influences of analytical parameters including pH and volume of sample, type and concentration of elution solution, flow rate of sample and elution solution, etc. were investigated on the recoveries of Mn(II) ion. The adsorption was achieved quantitatively for Mn(II) on XAD-4-SCHD resin at the pH range of 3–10 and 3 mL min–1 sample flow rate. Elution was performed with 0.5 mol L–1 nitric acid solution. Under the optimized conditions, calibration curve was found to be linear in the concentration range of 0.1–5 mg L–1 with a limit of detection of 0.65 μg L–1. The effect of foreign ions on the perconcentration and determination of Mn(II) was studied and no adversely affecting ion was observed even at high ionic media. The recovery value was above 90%, with an enrichment factor of 100. The per cent relative standard deviation (%) value was found to be 1.8 for twenty repetitive measurements containing 1 mg L–1 of Mn(II). Sorption capacity of the Mn(II) ion on the XAD-4-SCHD resin was found to be 29.217 μg. The accuracy of the presented preconcentration and determination method was checked by the analysis of TMDA-70.2 Ontario lake Water certified reference material and synthetic water sample. The method was applied for the analyses of tap water and industrial wastewater samples for Mn(II). Almost the similar results were observed for the Mn(II) determination in different environmental water samples using both the proposed and ICP-MS methods.