Analysis of steryl esters in cocoa butter by on-line liquid chromatography-gas chromatography

On-line liquid chromatography-gas chromatography (LC-GC) has been applied t o the analysis of steryl eaters in cocoa butter. Separation of the steryl e sters was achieved after on-line transfer to capillary GC. HPLC removes the large amount of triglycerides and pre-separates the components of interest , thus avoiding time-consuming sample preparation prior to GC analysis. The identities of the compounds were confirmed by CC-MS investigation of the c ollected HPLC fraction and by comparison of the mass spectra (chemical ioni zation using ammonia as ionization gas) to those of synthesized reference c ompounds. Using cholesteryl laurate as internal standard, steryl esters wer e quantified in commercial cocoa butter samples, the detection Limit being 3 mg/kg and the quantification limit 10 mg/kg, respectively. Only slight di fferences in percentage distributions of steryl esters depending on the geo graphical origin of the material were observed. The patterns were shown to remain unchanged after deodorization. The method described might be a valua ble tool for authenticity assessment of cocoa butter. (C) 2001 Elsevier Sci ence B.V. All rights reserved.