Ajg. Mank et Es. Yeung, DIODE LASER-INDUCED FLUORESCENCE DETECTION IN CAPILLARY ELECTROPHORESIS AFTER PRECOLUMN DERIVATIZATION OF AMINO-ACIDS AND SMALL PEPTIDES, Journal of chromatography, 708(2), 1995, pp. 309-321
Citations number
25
Categorie Soggetti
Chemistry Analytical","Biochemical Research Methods
The use of diode laser-induced fluorescence (DIO-LIF) detection in the
field of capillary electrophoresis (CE) is examined. A simple but sen
sitive detection system was constructed. The performance of the system
was evaluated with respect to design factors and its sensitivity was
compared with the theoretically achievable sensitivity. To enhance the
applicability of direct DIO-LIF detection in CE, a derivatization met
hod for amines was developed. A red-absorbing label, consisting of a d
icarbocyanine fluorophore with a succinimidyl ester functionality, was
synthesized for this purpose. After derivatization of 1 x 10(-6) M gl
ycine, a detection limit of 0.1 amol was observed for the labeled glyc
ine. Similar detection limits were observed for other amino acids. To
show that derivatization preserves the separation efficiency of CE for
the analytes examined, 18 amino acids and tyramine were separated wit
h micellar electrokinetic chromatography after labeling. In addition,
even labeled peptides, including structurally related enkephalin-type
compounds, were separated from each other with zone electrophoresis. T
o test the applicability of the derivatization method to biological sa
mples, tyramine was determined in urine before and after the consumpti
on of cheese.