Wavelet Transforms and Applications in Drug
Analysis
Erdal DİNÇ*°
* Ankara University, Faculty of Pharmacy, Department of Analytical Chemistry, 06100 Tandoğan, Ankara, Turkey
°Corresponding Author :
Phone: +90 (312) 203 31 76
Fax: +90 (312) 213 10 81
E-mail: dinc@ankara.edu.tr
SUMMARY
As it is known, the basis of the modern analytical chemistry is the
instrumental analysis methods based on the evaluation of analytical
signals such as spectra, chromatograms, kinetic curves and others
obtained from instruments. Nowadays, the traditional evaluation
of analytical signals may not always provide the desired results
for the chemical and pharmaceutical analysis, where most of the
analysis processes is hyper complex. Hence, combined application of
conventional instrumental methods and some chemometric signal
processing methods can be necessary for the analysis of complex
systems. As a result, conventional analysis techniques coupled with
signal processing tools enhance their ability of resolution, separation
and analysis tremendously. In this context, several signal processing
tools have been developed for many application areas from data
analysis to data compression. One of the newest additions has been
wavelets.
Wavelet transform (WT) can be classified into two categories;
discrete wavelets transform and continuous wavelets transform. WT
approach is a powerful signal processing tool for data reduction, denoising,
baseline correction and resolution of overlapping spectra. In
our previous studies, the WT signal processing tools in combination
with conventional spectral analysis techniques were applied to the
analysis of drugs in multicomponent samples. Very recently, fractional
wavelet transform was successfully applied to increase the lower signal
content and to reduce the spectral data length for the drug analysis.
In this review I will give some typical applications of the wavelet
transforms to spectrophotometric, voltammetric and chromatographic
signals for the analysis of drug substances.
Key Words:Drug analysis, chemometrics, signal processing, wavelet
transform, continuous wavelet transform, discrete wavelet transform.