Determination of 2-(4-morpholinyl)benzothiazole in environmental samples by a gas chromatograph equipped with a flame photometric detector

2-(4-Morpholinyl)benzothiazole (24MoBT) exists in automobile tire rubber as an impurity of a vulcanization accelerator and has been proposed as a potential molecular marker of street runoff (Spies, R. B.; Andresen, B. D.; Rice, D. W., Jr. Nature 1987, 327,697-699. The present paper describes an analytical method for 24MoBT in environmental samples (e.g., street dusts and river sediments) by gas chromatography. The method relies upon extraction with a 6:4 (v/v) mixture of benzene and methanol, purification by acid extraction, and adsorption column chromatography, followed by determination using capillary GC equipped with a sulfur-selective detector (i.e., FPD). The recovery of 24MoBT for the entire procedure was 85%, and the relative standard deviation for four replicated analyses was 1.5%. The detection limit was 0.08 ng injected 24MoBT, corresponding to 0.20 ng/g of dry sample. The selectivity and sensitivity of the present method permit the determination of 24MoBT at the trace levels (e.g., similar to ng/g) encountered in environmental samples. 24MoBT concentrations in various environmental samples are also reported.