Large Phase Ratio Spontaneous Extraction Followed by GC–MS for the Determination of Caffeine in Beverages
A single-step large phase ratio spontaneous extraction procedure followed by gas chromatography–mass spectrometry (GC–MS) was successfully applied for the determination of caffeine in beverages. Before the GC–MS analysis, as little as 25 μL sample was spontaneously extracted with 1 mL chloroform in a 2 mL autosampler vial for 15 min. The methodology exhibited excellent linearity in the range of 0.001–20 mg L−1 with correlation coefficient of determination, r 2 > 0.9999 and a detection limit of 0.004 mg L−1. Good repeatability of extraction performance was obtained with relative standard deviation lower than 2% and the recovery of the caffeine when spiked to three different brand beverages was in the range of 98.8–102.3%. The new application-oriented single-step spontaneous extraction method was fast, efficient, and is a good alternative to routine methods for caffeine analysis in beverages.
KeywordsGas chromatography–mass spectrometry Spontaneous extraction Large phase ratio Caffeine
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