Quantitative polarographic determination of some quaternary pyridine aldoximes

Abstract

It was demonstrated [1] that some quaternary pyridine aldoximes (2-PAM, 4-PPM, etc.), which have proved to be effective antidotes (cholinesterase reactivators) against organic compounds, are capable of generating nitric oxide during oxiclarion. It was therefore of interest to study the electrochemical reduction of these compounds on a mercury dropping electrode with a view to finding a method of their quantitative determination. At present, the most widely used quantitative method of oxime determination is based on their hydrolysis with concentrated sulfuric acid, followed by analysis of a distilled carbonyl compound or a bottom residue of hydroxylamine hydrochioride [2]. Other methods are based on the reaction of oxime reduction to amines (predominantly by trivalent titanium salts [3]). As is known, oximes exhibit electrochemical reduction on a mercury dropping electrode, which is a promising method for the synthesis of functionally substituted amines [4]. A general scheme of the electrochemical reduction of oximes in acid media according to Lurid [5] is as follows. The first stage is the rupture of nitrogen-oxygen bonds with the formation ofimines. This is followed by the reduction ofimines to amines: