Mixtures of organic and inorganic anions

Dionex Corporation [86] have issued a technical note covering the application of anion exchange chromatography to the determination of the very wide range of anions, quoted above, in non saline waters. 

Although the ionic strength of the eluant may remain the same throughout the run, the backgroimd conductivity can decrease due to the changing dielectric constant. These baseline changes can be compensated either by chemical means or by computer baseline subtraction. Often, mobile phase ion chromatography is used to elute ions which are very 

Source Reproduced with permission from the American Chemical Society [85] 

The analytical conditions recommended by Dionex for analysing mixtures of anions listed under the heading to this section are given below. 

Although many columns and eluants can be used for gradient elution, the conditions used in Figs. 2.16 and 2.17 are recommended as a good starting point. The HPIC-ASSA (5p) separator with sodium hydroxide eluant provides the optimum combination of efficiency, selectivity, and speed without an unacceptable baseline slope. If fewer ions than the 36 shown in Fig. 2.16 need to be separated, the gradient steepness can be increased to reduce the run time. 

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