Capillary liquid chromatographic determination of neutral phenolic compounds in apple juices

Capillary liquid chromatography (CLC) is evaluated as an alternative to conventional HPLC to analyse complex phenolics. Several neutral phenolic compounds were separated on a packed-reversed phase fused-silica capillary column, and determined with UV detection. A conventional liquid chromatographic equipment was adapted for such purposes. Application of the proposed method to the quantification of neutral phenols in apple juices is reported. Phenolics are extracted and fractionated into neutral and acidic compounds by means of a C18 solid-phase cartridge. Typical recoveries ranging from 90 to 105% are obtained and reproducibility between extractions is <7% in all cases. Mass detection limits are at the subnanogram level.