Polarography of Salicylic Acid - Analytical Chemistry (ACS Publications)

Electrochemical reduction of benzoic acid at mercury and lead electrodes. R.G. Barradas , O. ... Mechanism of the electrochemical reduction of salicyl...
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Polarography of Salicylic Acid N. HALE

CECIL H. HALE and MARGIE

Southwestern Analytical Chemicals, 7 707 W e s t Gibson St., Austin 4, Tex.

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H E polarographic reduction of benzoic acid has been reported by von Stackelberg and Stracke (6). They observed that the reduction occurred in two steps with half-wave potentials of - 1.94 and -2.46 volts 1's. S.C.E. Elving and Hilton ( 1 ) did not find a reduction wave for benzoic acid using lithium chloride and hydroxide as supporting electrolytes. It was suspected that the location of the hydroxyl group adjacent to the carboxyl group would make salicylic acid more easily reducible than benzoic. However, according to a paper published in 1949 ( 4 ) , salicylic acid was not found to be reducible in alkaline solutions of trt 1 amethylammonium hydroxide. With tetramethylammoniuni iodide as supporting electroll te> one reduction was observed at -1.66 to -1.83 volts, dtxpending upon the concentration of salicylic acid. This reduction was attributed hv the author