Quantification of melatonin and its photodegradation product by using the fractional wavelet transform – continuous wavelet transform

Recently, the fractional wavelet transform started to play a very important role in the area of signal analysis. This method was applied for the first time in pharmaceutical analysis and it was reported that this approach provides reliable and successufull results, particularly for the analysis of mixtures containing low and high concentration condition [1-3]. Especially, this new approach can be applied in combination with some standard chemometric techniques in order to get better analytical results. In this study a new signal processing approach based on the simultaneous use of fractional and continuous wavelet transforms were improved for the quantitative determination of melatonin and its photodegradation products in their samples. The UV spectra of melatonin and its degradation product were recoreded between 200- 455 nm and processed by the fractional wavelet algorithm.The obtained fractional wavelet coefficients were treated by biorthogonal and symplets wavelt families in order to quantify melatonic and its photodegradation product ,respectively. The calibration graphs for the related compounds were obtained by measuring the fractional-continuos amplitudes at 432 nm for melatonin and 435 nm for its degradation product. The validity and applicability of the double fractional and continuous wavelet transforms were tested by analyzing various synthetic mixtures of main compound and its degradation product. Successfful results were reported in the application of the improved fractional-continuous wavelet transform to the sample analysis.