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 hous e with 3 mum ODS1 stationary phase. The repeatability of the technique has been investigated with two neutral standard mixtures. Conditions for the an alysis have been optimised by varying several parameters such as applied vo ltage, temperature composition of the buffer and percentage of organic solv ent. 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 ob tained by high performance liquid chromatography (HPLC) in terms of time of analysis, resolution and efficiency. A study on the behaviour of oxygen he terocyclic compounds analysed with a "non-aqueous" mobile phase has also be en carried out.