OFF-LINE HYPHENATION OF THIN-LAYER CHROMATOGRAPHY WITH ATOMIC-ABSORPTION SPECTROMETRY IN THE STUDY OF THE STABILITY OF ZINC-COMPLEXES

Off-line hyphenation of two analytical methods, thin layer chromatogra phy (TLC) and atomic absorption spectrometry (AAS) has been used for a preliminary study of the stability of mixed zinc carboxylato complexe s with two nicotinic acid ligands during chromatographic separation on Silufol layers. The zinc content, determined by AAS, in fractions scr aped from the layers after chromatographic analysis of the complexes i s indicative of dissociation of the complexes during chromatography. I t was found that the chromatographic stability of the solutes is subst antially influenced by the concentration of organic modifier in the el uent. It was also confirmed that two nicotinic acid ligands are of dif ferent stability. The reproducibility of the TLC-AAS method was found to be 91%. The TLC-AAS method is simple, does not acquire additional e xpensive equipment, and can be used in many branches of interfaced ino rganic chromatographic analysis.