Analysis of oxygen heterocyclic compounds in citrus essential oils by capillary electrochromatography and comparison with HPLC

A new method for the analysis of oxygen heterocyclic compounds in bergamot, mandarin and sweet orange oils by capillary electrochromatography (CEC) is reported. The fused silica capillaries employed were slurry-packed in house with 3 mum ODS1 stationary phase. The repeatability of the technique has been investigated with two neutral standard mixtures. Conditions for the analysis have been optimised by varying several parameters such as applied voltage, temperature composition of the buffer and percentage of organic solvent. The best separations were obtained using the buffer acetonitrile/TRIS 10 mM at pH 7.8 in the ratio 80:20. The results were compared with those obtained by high performance liquid chromatography (HPLC) in terms of time of analysis, resolution and efficiency. A study on the behaviour of oxygen heterocyclic compounds analysed with a "non-aqueous" mobile phase has also been carried out.