Eluents potassium hydrogenphthalate

Fig. 3-28. Separation of various inorganic anions on a Wescan 269-001 silica-based anion exchanger. — Eluent 0.004 mol/L potassium hydrogenphthalate flow rate 1.5 mL/min detection direct conductivity injection volume no specification solute concentrations 10 ppm each (taken from [34]).

Fig. 3-62. Separation of inorganic anions using potassium hydrogenphthalate as the eluent. — Separator column Waters IC-PAK Anion eluent 0.001 mol/L KHP, pH 7.0 flow rate 2 mlVmin detection direct conductivity injection volume 10 pL solute concentrations 100 ppm each.

Potassium hydrogenphthalate is suited for the analysis of iodide, thiocyanate, and thiosulfate in combination with direct conductivity detection. When silica-based exchangers are used, some methanol or 2-propanol is added to the eluent to lessen adsorption effects. Fig. 3-77 shows such a separation, the characteristic of which is the elution of monovalent iodide prior to the divalent sulfate. Noticeable is the relatively long time... 

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