ELECTROCHEMICAL ENHANCEMENT OF HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY UV DETECTION FOR DETERMINATION OF PHENYLPROPANOLAMINE

A common difficulty for many high-performance liquid chromatographic (HPLC) analyses is the inadequate detectability of analytes in the chromatographic eluent. One of the most common detection modes for HPLC, UV absorption, is also amont the most problematic in this regard. A fast, simple and inexpensive solution to this problem is accomplished through an application of spectroelectrochemistry. A post-column electrochemical reactor placed before the UV detector was used to oxidize phenylpropanolamine (PPA), a common drug with a very low UV absorptivity, to species the UV absorptivities of which were significantly higher. The net effect of the oxidation was a significant enhancement of detector sensitivity for PPA. Electrochemical and spectroelectrochemical data, reactor design chanracteristics and application of the system to the analysis of PPA in dosage forms are presented. © 1990.