Authors:Daniel Jun, Petr Stodulka, Vit Koleckar, and Kamil Kuca
A quick and simple TLC method has been established for distinguishing among benzalkonium salts differing in the length of the side alkyl chain. The method could be used not only for determination of benzalkonium salts but also for distinguishing among other long-chain quaternary salts, for example tetraalkylammonium, pyridinium, quinolinium, and isoquinolinium compounds, used as micellar catalysts or as disinfectants.
Authors:Daniel Jun, Petr Stodulka, Martina Hrabinova, Miroslav Pohanka, Bohuslav Doleza, and Kamil Kuca
Four thin-layer chromatographic (TLC) methods for identification of twelve bisquaternary acetylcholinesterase reactivator HI-6 salts (sulfate, chloride, acetate, bromide, phosphate, mesylate, tartrate, iodide, malonate, salicylate, maleinate, and tosylate) are described. By use of TLC, particular E and Z isomers of each salt on the oxime group were also separated. These TLC methods could be of high interest for rapid identification of each salt and for purity control.
Authors:Tamás Csermely, Georg Petroianu, Kamil Kuca, Józsel Fűrész, Ferenc Darvas, Zsolt Gulyás, Rudolf Laufer, and Huba Kalász
Quaternary pyridinium aldoximes have been analyzed by thin-layer chromatography. Their separation was adequate when silica plates were used with a mobile phase with a high water content. As a consequence of their limited migration, reversed-phase TLC was not appropriate for determination of the lipophilicity of quaternary pyridinium aldoximes. Displacement TLC of some quaternary pyridinium aldoximes is, nevertheless, possible using silica as stationary phase with water-acetone-hydrochloric acid mobile phases. Normal-phase TLC with different concentrations of organic modifier gave a series of
values for the pyridinium aldoximes. Approximation of the different plots of
against organic modifier concentration to straight lines afforded
values and the slopes of the lines. The
values and the slopes both serve as indicators of the hydrophilic character of the compounds.
Authors:Gellért Balázs Karvaly, Kornélia Tekes, Zoltán Szimrók, József FŰrÉsz, Kamil KuČa, and Huba Kalász
Mono- and bis-pyridinium quaternary aldoximes (K-oximes) have long been employed as cholinesterase reactivator components of antidotes against lethal cholinesterase-inhibiting organophosphorous chemicals. Their positive charge poses difficulties in their chromatographic analysis, resulting in the publication of different approaches for each K-oxime. A multiplexed method is presented for the rapid quantitation of 10 K-oximes in blood with its utility demonstrated in vivo. Liquid chromatography with absorbance detection was employed. Reversed-phase separation was achieved on a highly nonpolar stationary phase. Method validation was based on the respective guideline of the European Medicines Agency. Times to peak concentrations and 120-min areas under the time–concentration curves were determined in rats following intraperitoneal administration. Adequate retention and separation of K-oximes with acceptable peak shapes in short isocratic runs was achieved by adjusting ionic strength, organic content and the concentration of the ion-pairing agent of the mobile phase. Chromatographic properties were governed by optimizing the concentration of dissolved ions. Accurate adjustment of the organic content was indispensable for avoiding peak drifting and splitting. Dose-adjusted exposure to K-347 and K-868 was exceptionally low, while exposure to K-48 was the highest. The method is suitable for screening systemic exposure to various K-oximes and can be extended.