An automated dispersive liquid-liquid microextraction method of detecting and quantifying N-nitrosamines in an aqueous sample. The method includes (a) extracting an aqueous solution comprising the N-nitrosamines by mixing an extraction solvent and a dispersive solvent with the aqueous solution, such that the N-nitrosamines, or a portion thereof, re-distribute from the aqueous solution to the extraction solvent, (b) permitting the resulting mixture in (a) to form a two-phase mixture comprising an aqueous phase comprising the aqueous solution with reduced amounts of the N-nitrosamines and an organic phase comprising the extraction solvent with the N-nitrosamines extracted from the aqueous solution, (c) injecting the organic phase, or a portion thereof, into an injection port of a gas chromatograph coupled with at least one mass spectrometer, and (d) analyzing the N-nitrosamines by gas chromatography and mass spectrometry to detect and quantify the concentration of the N-nitrosamines in the aqueous solution.