triple quadrupole mass spectrometry with liquid chromatography and dispersive liquid-liquid microextraction for the determination of monoterpenes in alcoholic drinks

Five monoterpenes (linalool, geraniol, eugenol, carvacrol, and thymol) were directly preconcentrated from alcoholic drinks with no previous sample treatment step using a miniaturized technique based on dispersive liquid-liquid microextraction. chloroform (300 μl) was rapidly injected into 8 ml of sample, while the addition of a disperser solvent was obviated because of the ethanol content of the alcoholic beverages. the enriched phase was evaporated, reconstituted in 50 μl water, and analyzed by reversed phase liquid chromatography with a mobile phase consisting of 25% acetonitrile (0.1% formic acid) and 75% water (0.1% formic acid) and tandem mass spectrometry with a triple quadrupole in the selected reaction monitoring mode. the matrix effect was evaluated, and quantification by the standard additions method is recommended. limits of detection ranged from 0.003 to 1.5 ng ml−1, depending on the compound and the matrix. enrichment factors of between 12 and 88 were obtained. the method was validated through recovery tests, finding values in the 76–128% range. the intraday precision was lower than 20% in terms of relative standard deviation. different types of alcoholic drinks were analyzed, monoterpenes being detected at concentrations from 0.4 to 627 ng ml−1.