INQUIMAE   12526
INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Detection of organic ionics by Ion Selective Electrodes used as an HPLC detector: applications to alkaloids in plant extracts
Autor/es:
M.R. FERNÁNDEZ; DEVIN DAEMS; JOSEPH EVERAERT; GUY VAN CAMP; DELIA L. BERNIK ; LUC NAGELS
Lugar:
Santa Fe
Reunión:
Congreso; VI Congreso Argentino de Química Analítica; 2011
Institución organizadora:
Asociación Argentina de Químicos Analíticos
Resumen:
In
the present study, we developed a potentiometric HPLC detector which
selectively detects the positively charged alkaloids from phenolic compounds
present in a plant extract. The characteristics of the detector, such as
selectivity, sensitivity, calibration curve behaviour, speed of response were
studied in FIA, using the sensorgram methodology.
Several
conditions such as temperature of the detection system, coating and eluent
composition were varied and their effect on the response times was compared.
The
detectors response is typical for a surface phenomenon dependent system,
showing on and off kinetics. Response speeds are described by a double
exponential function. These response times (t90) were calculated for cocaine
on and off kinetics being 2.154±0.055 and 1.191±0.033 seconds respectively.
Alkaloids as cocaine, ergocorine, solanidine and metergoline can be easily
detected at concentrations of 2.5 10-7M, 7 10-7M, 1 10-7M and 1.7 10-7M in HPLC
respectively. The detectors ability to be used as an alkaloids detector in
HPLC is was confirmed in several chromatograms, with UV detection for
comparison.
Alkaloids
can be sensitively detected and differentiated from other secondary plant
compounds in a plant extract without pre-purification. Potentiometry and UV
peak shape matching shows the applicability of this detector in HPLC.