Separation behavior of inorganic anions on an octadecyl-bonded silica column coated with cetyltrimethylammonium by phthalate and salicylate eluents

The separation behavior of seven common inorganic anions on an octadecyl-bonded silica (ODS) column coated with cetyltrimethylammonium (CTA(+)) by phthalate and salicylate eluents was examined with indirect UV detection. The separation became better with increasing anion-exchange capacity for the phthalate eluent, but not for the salicylate eluent. The CTA(+)-coated column, equilibrated with 1 mM CTA(+) in water-methanol (MeOH) (80:20, v/v) (anion-exchange capacity, 0.26 mequiv./column) and 1.5 mM sodium phthalate eluent (pH 6.8) was effective for the determination of inorganic anions in river and pond water samples.