1. Introduction
The objective of this lab experiment is to separate species of Fe(II), Ni(II) and Cu(II)
using ion exchange chromatography and to determine the effectiveness of the separation
using visible spectroscopy. Ion exchange chromatography relies on charge-charge
interactions between the ion(s) in the sample and the charges immobilised on the resin
used. In ion exchange chromatography, the stationary phase (resin) consists of a charged
polymeric matrix with active or counter-ions that will exchange reversibly with other ions
in a surrounding solution. The electric charge carried by the polymer is effectively
neutralised by the charges on the counter ions. Ion exchange chromatography can be
divided into cation exchange chromatography, in which the ion exchanger or stationary
phase (resin) is a polymeric anion with active cations that exchange reversibly with
cations in solution; and anion exchange chromatography which uses a polymeric cation
with active anions for separation. A strong anion exchange resin is used in this
experiment to separate the species. A qualitative determination of concentration of the
species and the effectiveness of the separation achieved by the ion exchange
chromatography is tested using visible spectroscopy. This procedure and the calculation
of various parameters enable the analyst to determine the differences in affinities of the
separating species for the resin used and their responses to changes in the composition of
the mobile phase.
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