Separation and preconcentration of MnVII/MnII speciation on crosslinked chitosan and determination by flame atomic absorption spectrometry.

A novel method for the separation and preconcentration of MnVII/MnII with crosslinked chitosan (CCTS) and determination by flame atomic absorption spectrometry (FAAS) has been developed. The adsorption rate of CCTS for MnVII was 98% at pH 3, while MnII was not adsorbed. MnVII was eluted from the CCTS with 10% (m/v) oxammonium hydrochloride and determined by FAAS. MnII was determined from the total manganese present after MnII in the water samples was transformed into MnVII. The detection limit (3 sigma, n = 10) for MnVII was 1.98 micrograms l-1 and the relative standard deviation less than 6.6% at the 10 micrograms l-1 level. The method was applied to environmental water samples with recoveries of between 95-103%.