Investigation of separation and identification possibilities of some metal-DEDTC complexes by sequential TLC-IR system

The separation and identification possibilities of some metal-diethyldithiocarbamate (DEDTC) complexes are investigated by thin-layer chromatography-IR sequential system. DEDTC complexes of metal cations are prepared in a predetermined optimum pH or pH range. Optimum separation conditions of these complexes and the reproducibilities of their retention factor (Rf) values are investigated on a series of precoated or laboratory-made TLC plates. Rf values are determined using the one-dimensional ascending technique. The precision of the procedures is determined for five replicates in terms of standard deviation. Detection limits are also determined for each of the metal complexes. The IR spectra are scanned and interpreted for their precise identifications after preconcentration with a wick-stick procedure for the complexes, giving the overlapped Rf values. The complexes could be identified by the aid of IR absorption bands. It has been determined that these IR absorption bands can also be used as reference spectral bands in possible quantitative studies. It is concluded that an efficient and successful qualitative analysis is possible for incompletely-separated complex compounds using an IR spectrophotometer as the TLC detector.