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.