Trace Anions in Samples Containing High Levels of Chloride or Sulfate

2 Trace Anions in Samples Containing High Levels of Chloride or Sulfate 

A good answer to this problem is to use an eluent containing the same ion as the sample matrix. Marheni, Haddad and McTaggart used eluents containing chloride or sulfate for samples containing a high concentration of chloride or sulfate, respectively 

With a 50 X 4.6 mm column packed with a polymethacrylate anion exchanger of 30 3 p/mL capacity, the chromatographic behavior of several anions was studied by direct photometric detection at 210 nm. Linear plots were obtained for log k (log retention factor) vs. log NaCl concentration in the eluent (Fig. 6.15). 

The eluent chosen for practical separations contained 15 mM sodium chloride and 5 mM phosphate buffer at pH 6.5. Separation of the ten anions gave very similar chro- 

Fignre 6.1S. Variation of log k with the concentration of chloride in the eluent. (From Ref. 16] with permission). 

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