Toxic effects of linear alkylbenzenesulfonate and quaternary alkylammonium chloride on Dunaliella sp. as measured by 1H-NMR analysis of glycerol

A new method to assess the toxic effects of linear alkylbenzenesulfonate (LAS : alkyl carbon number; 12) and quaternary alkylammonium chloride was established by using living green alga, Dunaliella sp.. This method is based on the 1H-NMR determination of glycerol which decreased quantitatively with increased concentrations of surfactants. The flagella immobilities and the cell mortalities following the exposure of LAS and TM (alkyltrimethylammonium chloride : alkyl carbon number ; 16–18 ) increased with decreased glycerol contents. High correlations were found between the glycerol contents and the flagella immobilities, and the cell mortalities. No leakage of glycerol of which detection limit was 0.02 mM/L media into the media was detected. The EC50-24h values of surfactants were 3.3 mg/L for LAS, 0.38 mg/L for TM, 18 mg/L for DM (dialkyldimethylammonium chloride : alkyl carbon number ; 16–18) and 1.8 mg/L for BM (alkyldimethylbenzylammonium chloride: alkyl carbon number; 12–14). The toxic potencies were in the order of TM>BM.LAS>DM.