Rapid Caffeine Profiling in Non- Alcoholic Beverages: Using Liquid-Liquid Extraction and FTIR Spectroscopy Approach

Abstract

Caffeine, a naturally occurring methylxanthine alkaloid, is commonly present in consumables such as coffee, tea, chocolate, soft drinks, and energy drinks. This study investigated the extraction and characterization of caffeine from various sources using liquid-liquid extraction followed by Fourier-transform infrared (FTIR) spectroscopy. The extraction utilized an organic solvent to selectively partition caffeine from aqueous matrices, and subsequent solvent evaporation yielded crude caffeine extract.

FTIR analysis enabled the identification of key functional groups in caffeine, based on characteristic infrared absorption bands. Notable peaks included carbonyl (C=O) stretching near 1650 cm⁻¹, C–N stretching around 1150 cm⁻¹, and N–H bending near 1550 cm⁻¹. Additional absorption bands observed in the 2800–3100 cm⁻¹ range corresponded to C–H stretching, whereas aromatic ring vibrations were detected at approximately 1500 cm⁻¹. Variations in the spectral intensity among the samples suggested differences in caffeine concentration and potential matrix interference.

The results confirm that liquid-liquid extraction is a robust method for isolating caffeine from complex mixtures, and FTIR spectroscopy serves as a rapid, non-destructive tool for its qualitative analysis. This methodology is relevant for routine quality control and comparative compositional analysis in the food and beverage industry.