Comparison of HPLC and GC-MS Analysis of Furans and Furanones in Citrus Juices

The lack of quantitative agreement between HPLC and GC-MS values for 2,5-dimethyl-4-hydroxy-3(2H)-furanone (Furaneol), furfural and 5-hydroxymethylfurfural reported in the literature is due to incomplete HPLC resolution. Furanoids of interest were not resolved from other citrus juice components using reversed phase HPLC with detection at 290 nm. Attempts to develop a rugged chromatographic separation to resolve all components were unsuccessful. A more accurate procedure was developed which employed a second detecting wavelength (335 nm) to provide maximum response from the interfering compounds and minimum response from the furanoids of interest. Reconstructed difference chromatograms (290-335 nm) negated interfering compounds thus providing the spectral selectivity to accurately quantify the furanoids of interest. GC-MS studies demonstrated that contrary to literature reports, Furaneol is thermally stable under GC conditions and can be chromatographically or spectrally resolved from other juice components.