Optimization of the amperometric detection of nitrite by reaction with iodide in a post-column reactor for liquid chromatography of non-volatile nitrosamines.

✍ Scribed by G.A. Sacchetto; G. Favaro; P. Pastore; M. Fiorani

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 835 KB
• Volume: 294
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(94)80308-0

✦ Synopsis

Following previous studies on this subject, the use of iodide reagent in acidic medium for the liquid chromatographic amperometric determination of non-volatile nitrosamines has been investigated in a two-line flow-injection manifold coupled with a voltammetric flow-through detector. The peak current signals obtained for the nitrite-iodide reaction were compared with those obtained for the iodate-iodide reaction used as a reference for the production of the electroactive species I;. The effect of adsorption-desorption phenomena on the reactor walls was investigated and analyzed by the "exponentially modified Gaussian" model applied to flow-injection peaks obtained under different experimental conditions, as to composition of the carrier liquid (water and water-acetonitrile mixtures), concentration of the reagent'and temperature of the reactor. From an analytical point of view, the method ensures a satisfactory linear response, a higher sensitivity and a much lower detection limit (about 1 X lo-' M) than those found with the cerium(IV) reagent, and a comparable band broadening and tailing.