Three-component electrocatalytic

The sensitivity increase for some selective carbohydrates that is caused by the addition of Ba(II) is shown in Figure 3.229. While retention of the first three components remains practically the same when adding barium acetate, a slight retention decrease is observed for fructose and sucrose. At first view, this seems surprising one might suppose that the complete removal of carbonate would lead to a retention increase. However, since in this case Ba(II) has been added as acetate salt, and acetate is a stronger eluent than hydroxide, even traces of acetate in the mobile phase will result in a retention decrease. The sensitivity increase is attributed by Cataldi et al [219] to the inhibition of the gold oxide formation by alkaline-earth metals in the order Ca(ll) > Sr(II) > Ba(II) that, in turn, results in an increase of the electrocatalytic activity of the electrode. 

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