Indirect electrochemical detection of cations with cerium(III) in the mobile phase.

Cerium(III) has been used in the mobile phase for indirect electrochemical chromatography of cations. Lithium, sodium, ammonium, and potassium ions have been separated within 4 min and detected with both glassy carbon and Kel-F wax carbon paste electrodes. With a Kel-F wax/graphite electrode at 0.7 V, the detection limit for sodium, ammonium, and potassium ions are 1.5, 1.1, and 2.0 ppm, respectively.

Pre- and postcolumn derivatization chemistry in conjunction with HPLC for pharmaceutical analysis.

Descriptions of derivatization reactions applied to high-performance liquid chromatography for pharmaceuticals classified as alkaloids, amines, antibiotics, barbiturates, carbonyl/carboxylic compounds, catecholamines, hydroxy compounds, steroids, sulfur compounds, and miscellaneous are summarized.