Evaluating Spectrophotometric Results The absorbance data is plotted on a graph on which the ordinate is absorbance and abscissa is tube number or fraction number. The absorbance scale need not be the same for each ion; maximum absorbance for each ion should simply be the top ofthe graph. Plot absorbance versus tube number for each ion, and connect the absorbance values with a smooth curve. In evaluating the efficiency of the separation, recall that ideally each ion would be removed totally from the column before a new one begins t o elute. Practically, however, each ion first appears in the eluant in low concentration, reaches a maximum and then taners off. As one ion's concentration decreases. another ion appears in the eluant. Some nv~rlnpof the lorn ulll rherefwr w w r duril~gthe elution. A separation may br cunsirlwrd rrawnahlr fur the purposes of this exprrlmtnl if the mnxlmum
