Levels of the PCB-substitute Ugilec (tetrachlorobenzyltoluene) in fish from areas of extensive mining

Abstract

Tetrachlorobenzyltoluenes, which represent the major constituent of the PCB substitutes Ugilec 141 and Ugilec T, have been widely used in the last few years as hydraulic fluids in underground mining. Their use has been termed a "closed application", but there are obviously considerable losses. Tetrachlorobenzyltoluenes released underground can enter the environment vit pia water, mine outputs or ventilation systems and as a consequence they can contaminate the food-chain, especially in fish. In fish from areas where there is extensive mining concentrations of tetrachlorobenzyltoluenes in edible portions ranged up to 25 mg/kg. The compounds were extracted from the freeze-dried material with petroleum ether. Gel chromatography on Bio-Beads S-X3 was chosen for the removal of fat followed by adsorption chromatography on silica gel according to the method of Specht and Tillkes. A combination of gas chromatography/mass spectrometry employing an ion trap detector was used for the separation and detection of the compounds. The great selectivity of mass selective detection combined with the high resolving power of capillary gas chromatography made it possible to determine and confirm the presence of Ugilec in fish down to a level of 0.02 mg/kg, even if there was a large PCB surplus.