Determination of zinc diethyldithiocarbamate released into artificial sweat from natural rubber latex vulcanizates by HPLC

A simple high-performance liquid chromatography method is adopted in order to quantitate the amount of zinc diethyldithiocarbamate (ZDEC) released into artificial sweat from natural rubber latex vulcanizates. The artificial sweat is extracted with dichloromethane, and the residue is recovered and redissolved in a known quantity of dichloromethane. ZDEC is quantitated as its copper complex by reacting with copper(ll) sulphate. A reversed-phase C18 column and detection wavelength of 435 nm are used to measure the copper-dithiocarbamate complex. The procedure is repeated with cobalt(ll) chloride, and the amount of ZDEC obtained by both the methods is compared. It is found that the recovery of ZDEC from the artificial sweat is high when copper(ll) sulphate is used, indicating that the copper(ll) sulphate is a better complexing agent than cobalt(ll) chloride under the conditions used in the present study. The limits of detection and the quantitation of ZDEC are found to be 0.25 and 0.86 pg/mL, respectively. The present method, based on precolumn derivatization using copper(ll) sulphate, facilitates the quantitation of ZDEC in latex products.