Separation of delta-, gamma- and alpha-tocopherols by CEC.
In this study capillary electrochromatography (CEC) was used for the separation of three tocopherols (TOHs), namely delta-, gamma- and alpha-TOH and the antioxidant compound, butylated hydroxytoluene (BHT). The CEC experiments were carried out using an octadecylsilica (ODS) stationary phase packed, in our laboratory, in a fused-silica capillary (100 microm I.D., 365 microm O.D. x 33 cm of total length and 24.6 or 8.4 cm effective length). The mobile phase was composed by a mixture of methanol (MeOH) and acetonitrile (ACN), at different concentrations and 0.01% (w/v) of ammonium acetate. Retention time (t(R)), retention factor (k), resolution (R(s)) of the three TOHs were strongly influenced by the organic solvent composition of the run buffer and by the effective length of the capillary. Optimum experimental conditions were found even employing the short effective length of the capillary achieving the baseline separation of the studied analytes in a relatively short time (less than 5 min). The optimized method was applied to the qualitative analysis of vitamin E (alpha-TOH) present in a human serum extract.
Istituto di Cromatografia del C.N.R., Area della Ricerca di Roma, Via Salaria Km 29,300-C.P., P.O. Box 10, Monterotondo Scalo, Rome, Italy.
Salvatore
S
Fanali
Paolo
P
Catarcini
Maria Giovanna
MG
Quaglia
Emanuela
E
Camera
Mariarosa
M
Rinaldi
Mauro
M
Picardo
D000975:Antioxidants / Q000302:isolation & purification*; D002084:Butylated Hydroxytoluene / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods; D006801:Humans; D007202:Indicators and Reagents; D024502:alpha-Tocopherol / Q000097:blood / Q000302:isolation & purification*; D024504:gamma-Tocopherol / Q000097:blood / Q000302:isolation & purification*
D000975:Antioxidants; D007202:Indicators and Reagents; D002084:Butylated Hydroxytoluene; D024504:gamma-Tocopherol; D024502:alpha-Tocopherol