Evaluation of data produced by optode arrays under flow injection analysis (FIA) conditions using a partial least
1Lehrstuhl für Biologische Chemie, Technical University of Munich, Germany.
Journal of Biochemical and Biophysical Methods
|October 8, 1999
Summary
This study demonstrates a method for simultaneously determining penicillin and ampicillin using an enzyme optode at two pH levels. Simple linear regression effectively analyzes spectral data, enabling accurate quantification of these antibiotics.
Area of Science:
- Analytical Chemistry
- Biomedical Engineering
- Spectroscopy
Background:
- Simultaneous determination of antibiotics like penicillin and ampicillin is crucial for quality control and therapeutic monitoring.
- Enzyme optodes offer a sensitive platform for detecting specific analytes.
- Developing robust methods for analyzing complex mixtures from optode signals is essential.
Purpose of the Study:
- To develop and validate a method for the simultaneous determination of penicillin and ampicillin using an enzyme optode.
- To evaluate the effectiveness of different pH working points for sample discrimination.
- To assess the utility of partial least-squares (PLS) regression for analyzing time-dependent spectral data.
Main Methods:
- Transient diffuse reflectance spectra in the visible range were acquired from an enzyme optode.
- The optode was operated at two distinct working pH values to differentiate between penicillin and ampicillin.
- Flow injection analysis (FIA) was employed, and data were analyzed using ordinary linear regression and partial least-squares (PLS) with cross-validation.
Main Results:
- A linear range in time-dependent signals was observed and successfully fitted using ordinary linear regression.
- Partial least-squares (PLS) analysis, utilizing static and dynamic features, enabled effective evaluation of the enzyme-catalyzed reaction.
- Interpretation of spectral loadings and correlation matrices identified optimal variable sets, leading to a robust analytical model.
Conclusions:
- The enzyme optode, operated at two pH values, successfully discriminated and allowed for simultaneous determination of penicillin and ampicillin.
- Ordinary linear regression proved sufficient for on-line pre-processing, effectively avoiding systematic errors.
- PLS regression, combined with careful variable selection, provided a powerful tool for analyzing complex spectral data from enzyme optodes.
