Biomedical subjects

S Sentellas

Publications and source records attributed to S Sentellas.

5 recordsLinked to original sources

PubMed2003

Quantitation in multianalyte overlapping peaks from capillary electrophoresis runs using artificial neural networks.

The potentiality of artificial neural networks for multicomponent analysis in unresolved peaks from capillary electrophoresis (CE) is evaluated. The system chosen consists of mixtures of three ebrotidine metabolites, which cannot be successfully separated by CE. Data selected for analysis consist of UV spectra taken at the maximum of the CE peak. The most dissimilar analyte, in terms of spectral differences, is accurately quantitated in any type of mixture with an overall prediction error of 5%. Because of the strong interference of the two most overlapped compounds, a preliminary procedure for spectral data filtering based on principal component analysis is performed to improve their quantitation.

Electrophoresis, Capillary↗

PubMed2002

Determination of ebrotidine and its metabolites by micellar electrokinetic capillary chromatography.

Ebrotidine and its potential metabolites were determined by micellar electrokinetic capillary chromatogaphy (MECC) using sodium dodecylsulfate (SDS) as surfactant. The influences of buffer composition, SDS concentration and addition of a neutral surfactant such as Brij 35 were studied. A 40 mM phosphate buffer at pH 7.50 containing 50 mM of SDS was selected as carrier electrolyte, and provided the optimum separation with regard to resolution and migration time. Linear calibration curves over the range studied (5.0-50 microg ml(-1)), limits of detection between 0.25 and 2.0 microg ml(-1) and run-to-run precision lower than 10% were obtained. The MECC method was applied to the determinaton of these compounds in spiked human urine.

Benzenesulfonates↗

PubMed2001

Multivariate calibration methods for quantification in strongly overlapping capillary electrophoretic peaks.

Capillary zone electrophoresis with diode-array detection was applied to the separation of ebrotidine and its metabolites. However, three of these, which are neutral in the conditions studied, co-migrated with the electroosmotic flow signal. Therefore, strongly overlapping peaks were observed. The main aim of this study was to show the potentiality of capillary electrophoresis in combination with chemometrics. Multivariate calibration methods were applied to quantify these analytes in synthetic mixtures. The results obtained using partial least squares (PLS) were in agreement with actual values, with an overall prediction error of 9.7%.

Calibration↗

PubMed2001

Determination of ebrotidine metabolites in overlapping peaks from capillary zone electrophoresis using chemometric methods.

This paper illustrates the possibilities of chemometric methods in the resolution and quantification of various compounds in overlapping peaks from capillary electrophoresis. Ebrotidine and most of its metabolites were efficiently separated by capillary zone electrophoresis (CZE) in a fused-silica capillary. However, the procedure was not suitable for the physical separation of the three less ionizable metabolites, which comigrated and overlapped with the electroosmotic flow signal. Multivariate curve resolution based on an alternating least squares procedure was used for their mathematical resolution. For such a purpose, data obtained in the CZE system with a diode array detector, which consisted of UV spectra registered over time, were analyzed. The ebrotidine metabolites were successfully resolved and quantified in synthetic mixtures and urine samples.

Benzenesulfonates↗

PubMed2000

Determination of ebrotidine and its metabolites by capillary electrophoresis with UV and mass spectrometry detection.

This study describes the application of capillary electrophoresis (CE) to the analysis of ebrotidine and its metabolites as an alternative analytical technique to liquid chromatography. Comparison between UV-diode array spectroscopy and mass spectrometry (MS) using an ion-trap system with electrospray ionization as detection systems has been performed. The quality parameters of the UV detection method were established, obtaining linear calibration curves over the range studied (8-200 mg ml(-1)), limits of detection between 3.4 and 4.3 microg ml(-1), and run-to-run and day-to-day precision lower than 14%. For these compounds the protonated species [M+H]+ and, in some cases, sodium adducts were observed in the MS spectra. Using MS coupled to CE, limits of detection were between 0.5 and 2.6 microg ml(-1).

Benzenesulfonates↗