A Note on: A Simple and Rapid High Performance Thin-Layer Chromatographic Method for the Separation and Identification of Heavy Metal Dithiocarbamates and Related Compounds

Abstract

Dithiocarbamates and other accelerators such as thiuram sulphides (thiurams), are widely used in the Rubber Industry for the curing of natural and synthetic rubber, as stabilisers against ultra-violet radiation, and as heat-ageing inhibitors (antioxidants). Analytical methods for these compounds have been reviewed by Burger[1] and Auler[2], the latter giving special emphasis to paper chromatographic methods. Prior to 1965 very few applications of thin-layer chromatography (TLC) were reported in this field. However, in 1969 Kreiner and Warner [3] published detailed methods for the identification of many rubber compounding ingredients by TLC using plates self-coated with Merck Silica Gel G (Non-fluorescent). The visualization procedures employed by these workers were complex. In 1970 Rai and Kukreja[4] published a short paper on the separation of the diethyl dithiocarbamates of bismuth, cobalt, copper, chromium lead, mercury, nickel, palladium, silver, thallium and uranium, using very simple eluents and the same adsorbent. Compounds were detected by their own color or visualized using yellow ammonium sulphide. Solution strengths and application volumes were not reported. Onuska[5] quantitatively determined various N,N-dialkyldithiocarbamates and thiurams in waste waters using Eastman pre-coated 6060 silica gel fluorescent plates and a densitometer.