Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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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: 6Citation - Scopus: 7Fractional-Continuous Wavelet Transforms and Ultra-Performance Liquid Chromatography for the Multicomponent Analysis of a Ternary Mixture Containing Thiamine, Pyridoxine, and Lidocaine in Ampules(Oxford Univ Press inc, 2012) Baleanu, Dumitru; Dinc, ErdalNew chemometric approaches based on the application of partial least squares (PLS) and principal component regression (PCR) algorithms with fractional wavelet transform (FWT) and continuous wavelet transform (CWT) are proposed for the spectrophotometric multicomponent determination of thiamine hydrochloride (B-1), pyridoxine hydrochloride (B-6), and lidocaine hydrochloride (LID) in ampules without any separation step. In this study PLS and PCR techniques were applied to the raw spectral data, FWT-coefficients, and FWT-CWT-coefficients. These calibration models were labeled as Raw-PLS and Raw-PCR, FWT-PLS and FWT-PCR, and FWT-CWT-PLS and FWT-CWT-PCR, respectively. A new ultra-performance liquid chromatographic (UPLC) method was developed for the comparison of the results obtained by applying the chemometric calibration methods. Chromatographic separation and determination of B-1, B-6, and LID in ampules were performed on an Acquity UPLC (R) BEH C18 column (50 x 2.1 mm id, 1.7 mu m particle size) using gradient elution with a mobile phase consisting of methanol and 0.01 M HCl at a constant flow rate of 0.6 mL/min. These combined chemometric calibrations and UPLC were validated by analyzing various ternary mixtures, B-1, B-6, and LID. The proposed chemometric approaches (signal processing-multivariate calibrations) and UPLC method were applied to the quantitative multicomponent analysis of marketed ampules containing the vitamins B1 and B-6 with LID.Conference Object Citation - WoS: 8Citation - Scopus: 9Fractional Wavelet Transform-Continous Wavelet Transform for the Quantification of Melatonin and Its Photodegradation Product(Taylor & Francis inc, 2012) Ragno, Gaetano; Baleanu, Dumitru; De Luca, Michele; Ioele, Giuseppina; Dinc, ErdalIn this study a new signal processing approach based on the simultaneous use of fractional and continuous wavelet transforms was suggested for the quantitative estimation of melatonin and its photodegradation products in their samples. The UV spectra of melatonin and its degradation product were recorded between 200.0 and 455.0 nm and processed by the fractional wavelet algorithm. The obtained fractional wavelet coefficients were treated by biorthogonal and symplets wavelet families in order to quantify melatonic and its photodegradation product, respectively. The calibration graphs for the related main compound and its degradation product were obtained by measuring the fractional-continuous wavelet amplitudes at 432.0 nm for melatonin and 435.0 nm for its degradation product. The validity and applicability of the double transforms based on fractional and continuous wavelets were confirmed by analyzing various synthetic mixtures of melatonin and its degradation product. Successful results were reported in the application of the improved fractional-continuous wavelet transform to the sample 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.Article Citation - WoS: 29Citation - Scopus: 30Fractional Wavelet Analysis for the Simultaneous Quantitative Analysis of Lacidipine and Its Photodegradation Product by Continuous Wavelet Transform and Multilinear Regression Calibration(Oxford Univ Press inc, 2006) Ragno, Gaetano; Ioele, Giuseppina; Baleanu, Dumitru; Dinc, ErdalFractional wavelet transform (FWT) was applied to the original absorption spectra of lacidipine (LAC) and its photodegradation product (LACD), and the resulting FWT spectra were processed by continuous wavelet transform (CWT) and multilinear regression calibration (MLRC) for the simultaneous quantitative analysis of both products in their binary mixtures. These methods do not require any chemical separation step and chemical complex reaction to obtain a detectable signal for the degradation product. By using the Mexican hat function, 2 calibration functions for LAC and LACD were obtained by measuring the CWT transformed signals at 416.1 nm for LAC and 414.6 nm for LACD, after FWT processing of the original absorption spectra. The calibration graphs were linear in the concentration range of 5.08-40.64 mu g/mL for LAC and 0.51-8.16 mu g/mL for LACD. The limit of detection and the limit of quantitation were found to be 0.289 and 0.956 mu g/mL for LAC and 0.036 and 0.118 mu g/mL for LACD, respectively. For comparison, the MLRC algorithm was applied to the linear regression functions for the individual drug and its photoproduct. In this approach, a set of linear regression functions was obtained from the relationship between concentrations and FWT signals in the wavelength range 411.0-412.4 nm. Both methods were applied to the quantitative evaluation of LAC and LACD in laboratory and pharmaceutical samples, and produced very satisfactory results.