ASSESSMENT OF THE TOXICITY OF LINEAR ALKYLBENZENE SULFONATE AND QUATERNARY ALKYLAMMONIUM CHLORIDE BY MEASURING C-13-GLYCEROL IN DUNALIELLA SP

The toxic effects of linear alkylbenzenesulfonate (LAS) and quaternary alkylammonium chloride on Dunaliella sp. were studied by measuring C- 13-glycerol. C-13-glycerol (five isomers of [1,2,1'-C-13(1,2,3)]-glyce rol) was produced in Dunaliella sp. from C-13-sodium bicarbonate added and the amounts of C-13-glycerol was lowered quantitatively with incr eased concentration of surfactants. The ratio of glycerol to C-13-glyc erol was found to be about 45:55 by gas chromatographic/mass spectrome tric analysis. The 24-h median effective concentration (EC50-24h) were 3.5 mg/l for LAS, 0.79 mg/l for alkyltrimethylammonium chloride (TM), 18 mg/l for dialkyldimethylammonium chloride (DM) and 1.3 mg/l for al kyldimethylbenzylammonium chloride (BM) : the toxic potencies were in the order of TM>BM>LAS>DM. The suppression of C-13-glycerol formation by LAS seemed to be related to the process of photosynthesis from C-13 -sodium bicarbonate. (C) 1997 Elsevier Science Ltd.