Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Article Citation - WoS: 5Citation - Scopus: 9Combined Application of Continuous Wavelet Transform-Zero Crossing Technique in the Simultaneous Spectrophotometric Determination of Perindopril and Indapamid in Tablets(Soc Brasileira Quimica, 2009) Pektas, Goezde; Baleanu, Dumitru; Dinc, Erdal; Baleanu, Dumitru; Pektag, Gözde; MatematikSignal processing methods based on the combined use of the continuous wavelet transform (CWT) and zero-crossing technique were applied to the simultaneous spectrophotometric determination of perindopril (PER) and indapamide (IND) in tablets. These signal processing methods do not require any priory separation step. Initially, various wavelet families were tested to identify the optimum signal processing giving the best recovery results. From this procedure, the Haar and Biorthogonal 1.5 continuous wavelet transform (HAAR-CWT and BIOR 1.5-CWT, respectively) were found suitable for the analysis of the related compounds. After transformation of the absorbance vectors by using HAAR-CWT and BIOR 1.5-CWT, the CWT-coefficients were drawn as a graph versus wavelength and then the HAAR-CWT and BIOR 1.5-CWT spectra were obtained. Calibration graphs for PER and IND were obtained by measuring the CWT amplitudes at 231.1 and 291.0 rim in the HAAR-CWT spectra and at 228.5 and 246.8 nm in BIOR 1.5-CWT spectra. respectively. In order to compare the performance of HAAR-CWT and BIOR 1.5-CWT approaches, derivative spectrophotometric (DS) method and HPLC as comparison methods, were applied to the PER-IND samples. In this DS method, first derivative absorbance values at 221.6 for PER and 282.7 nm for IND were used to obtain the calibration graphs. The validation of the CWT and DS signal processing methods was carried out by using the recovery study and standard addition technique. In the following step, these methods were Successfully applied to the commercial tablets containing PER and IND compounds and good accuracy and precision were reported for the experimental results obtained by all proposed signal processing methods.Article Citation - WoS: 13Citation - Scopus: 18Continuous Wavelet Transform and Chemometric Methods for Quantitative Resolution of a Binary Mixture of Quinapril and Hydrochlorothiazide in Tablets(Soc Brasileira Quimica, 2007) Baleanu, Dumitru; Dinc, Erdal; Baleanub, DumitruQuantitative resolution of the quinapril and hydrochlorothiazide mixture in tablets was achieved by using continuous wavelet transform and chemometric methods. In the case of the continuous wavelet transform, various continuous wavelet families were tested in order to find the optimum point of the wavelet signal processing technique. The Mexican hat wavelet function was reported to be the optimal one. The Mexican hat wavelet function was applied to the absorption spectra of quinapril and hydrochlorothiazide in the spectral range of 200-320 nm for standard series of drugs in the concentration range of 4.0-20.0 mu g mL(-1) quinapril and 2.5-12.5 mu g mL(-1) hydrochlorothiazide. The calibration functions for quinapril at 230.6 nm and for hydrochlorothiazide at 271.1 nm were calculated based on the relationship between the measurements of continuous wavelet signals and their concentrations. According to the chemometric approach, partial least squares and principal component regression calibrations were constructed by a training set of 21 mixtures, containing two drugs and their corresponding absorbance data, in the wavelength range of 205-290 nm. All proposed methods were validated by the independent analysis of the synthetic mixtures and by the standard addition technique. The application of the methods indicated that their selectivity and the sensitivity were satisfactory. The investigated methods were successfully applied to tablet analysis.Article Citation - WoS: 15Citation - Scopus: 16Application of Haar and Mexican Hat Wavelets To Double Divisor-Ratio Spectra for the Multicomponent Determination of Ascorbic Acid, Acetylsalicylic Acid and Paracetamol in Effervescent Tablets(Soc Brasileira Quimica, 2008) Baleanu, Dumitru; Dinc, ErdalSimultaneous determination of ascorbic acid (AA), acetylsalicylic acid (ASP) and paracetamol (PAR) in their synthetic mixtures and effervescent tablets were performed by Haar and Mexican continuous wavelet transforms (HAAR-CWT and MEXH-CWT, respectively) together with double divisor technique. The signal processing methods are based on the application of HAAR-CWT and MEXH-CWT to the double divisor-ratio spectra (DDRS). These spectra were obtained by dividing the absorption spectra of pure compound and its ternary mixtures by a double-divisor or standard spectrum corresponding to a mixture of two compounds in ternary mixture. A combined use of HAAR-CWT and MEXH-CWT with double divisor-ratio spectra (DDRS) was denoted by DDRS-HAAR CWT and DDRS-MEXH CWT. To check the ability or applicability of the developed DDRS-CWT methods, the double divisor-ratio spectra-derivative spectrophotometric (DDRS-DS) method, as a comparison method, was applied to the above mentioned samples containing AA, ASP and PAR and satisfactory results were obtained.