INVESTIGADORES
GOICOECHEA hector Casimiro
congresos y reuniones científicas
Título:
Multiresponse simultaneous optimization applied to epinastine determination in human serum by using capillary electrophoresis
Autor/es:
GOICOECHEA, HÉCTOR C; AC OLIVIERI,; VERA CANDIOTI, LUCIANA
Lugar:
Campinas
Reunión:
Congreso; 10th Internacional Conference on Chemometrics in Analytical Chemistry (CAC 2006); 2006
Institución organizadora:
CAC
Resumen:
The design of the experiments and the optimization of the experimental
procedures for chemical measurements constitute an important area of chemometrics.
The
objectives of their application involve the study of the influence of different
factors over a certain objective function, in order to find the experimental conditions
for the simultaneous optimization of the response. This allows to develop
quantitative methods with properties such as high resolution, sensitivity and
specificity, as well as decreasing costs and operational time.
On the other
hand, it is known that separation by capillary electrophoresis depends on many different
factors. As a consequence, the simultaneous study of all the potential factors becomes
a complex task, mainly because it requires to spend a long time to carry out the
analyses.1
In the present work, a Plackett-Burman
experimental design was applied to the determination of the main factors affecting
the peak resolution between the target analyte (epinastine) and lidocaine hydrochloride,
used as an internal standard.
The analyzed factors were:
concentration and pH of the buffer, voltage and time of injection, and voltage
of separation.
An ANOVA test was applied to the
experimental data with the following results that injection voltage, injection time
and pH of the buffer are all significant (p < 0.05).
Subsequently, three responses: resolution, wide and
area of the epinastine peak were simultaneously optimized by resorting to the
desirability function, which allows one to find experimental conditions where
the system generates desirable results. 2,3
A central composite design consisting of twenty experiments
was used. It was built with combinations of the independent variables in the
following ranges: pH 3.00 4.00, voltage of injection 5 10 kV and time of injection 10
20 seconds. The latter ranges were
selected based on the prior knowledge of the system under study. On the other
hand, the buffer concentration and the separation voltage were set at 20 mmol.
L1 and 20 kV, respectively. The wavelength detector was set at 214
nm and the temperature was fixed at 25 ºC.
The experimental conditions corresponding to a maximum
of the desirability function (D = 0.713) are:
20 mmol. L1 of buffer concentration, pH 4.00, voltage of
separation of 20 kV, voltage of injection of 5 kV and 20 seconds of time of
injection.
Finally, the selected conditions were applied to the analysis of
epinastine in human serum samples.