WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653
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Article Citation - WoS: 8Citation - Scopus: 8Determination of Salicin Content of Some Salix L. Species by Hplc Method(Chiminform Data S A, 2007) Guvenc, Aysegul; Baleanu, Dumitru; Arihan, Okan; Altun, M. Levent; Dinc, Erdal; Baleanu, Dumitru; MatematikIn this paper, we find the salicin content of the nine species of Salix L from the province of Ankara, Turkey, namely Salix triandra, S. alba, S. excelsa, S. fragilis, S. babylonica, S. caprea, S. cinerea, S. pseudomedemii and S. amplexicaulis. A simple HPLC method was applied to the determination of Salicin of these nine species in barks and leaves of female and male. Chromatographic separation was carried out by a mobile phase consisting of bidistilled water, tetrahydrofuran and ortho-phosphoric acid (97.7: 1.8: 0.5) (v/v/v). The salicin amount of these samples was analyzed by measuring the peak area at the wavelength, 270 nm. A reversed phase phenyl column (250 x 4.6mm, 5 mu m) was used and flow rate was set to 1 ml/min. in an isocratic elution. The results provided 6 HPLC method was found in agreement with those indicated by European Pharmacopoeia. It was observed that S. babylonica female bark sample possess the highest salicin content (2.675), while S. caprea female bark (0.058) has the lowest salicin content as w/w (%).Article Citation - WoS: 7Citation - Scopus: 6Simultaneous Determination of Chlorotetracycline and Benzocaine in Bolus by Chemometric Methods(Chiminform Data S A, 2007) Dinc, Erdal; Baleanu, Dumitru; Kanbur, Murat; Baleanu, Dumitru; MatematikTwo chemometric methods were applied to the simultaneous determination of chlortetracycline (CTC) and benzocaine (BC) in their binary mixture. The methods involve multivariate calibration based on principal least-squares (PCR) and partial least-squares (PLS) regressions. A concentration set consisting of binary mixtures of CTC and BC in 13 different combinations were randomly prepared in 0,011 M HCl. Both multivariate calibration models were constructed by using the relationship between the concentration set and its corresponding absorption data in the spectral region of 200-305 nm, The accuracy and the precision of the methods were validated by analyzing synthetic mixtures containing investigated drugs. The recovery results obtained by applying PCR and PLS calibrations to artificial mixtures were found between 100.2 and 101.0%. Data treatments, regressions and statistical analysis were performed by using the Microsoft EXCEL and PLS toolbox 3.5 in Matlab 7.0 software. Satisfactory results for both artificial and commercial veterinary samples were obtained. The experimental results from two chemometric methods were compared with each other.Article Citation - WoS: 3Citation - Scopus: 5Simultaneous Determination of Quinapril and Hydrochlorothiazide in Tablets by Ratio Spectra Derivative Spectrophotometric and Chemometric Methods(Chiminform Data S A, 2007) Dinc, Erdal; Baleanu, Dumitru; Altynoz, Sacide; Baleanu, Dumitru; MatematikSimultaneous determination of quinapril (QA) and hydrochlorothiazide (HCT) in tablets were accomplished by ratio spectra first order derivative spectrophotometry (graphical method) and chemometric method (numerical method). Both methods do not require any chemical separation step. In the application of two analytical methods, the absorption spectra in the working range of 4.0-20.0 mu g/mL QA and 2.5-12.5 mu g/mL HCT were plotted in the wavelength range of 210-350 nm. In the graphical approach, the absorption spectra of QA and its binary mixtures in the selected spectral range of 210-280 nm were divided by the standard spectrum of 10 mu g/ mL HCT and their absorption spectra were obtained. In the similar way, the ratio spectra of HCT in the wavelength region of 210-350 nm were also obtained by using the standard spectrum of 12 mu g/mL QA. First derivative of the ratio spectra obtained in the above steps were calculated by Delta lambda=5 nm interval for both drugs. Calibration equation functions were obtained by measuring (he ratio spectra derivative amplitudes of the minima at 219.9 nm for QA and 283.2 nm for HCT in the above mentioned spectral ranges for each drug. In the numerical method, the critical wavelengths corresponding to maximum points at 213.0 nm for QA and 220.0 nm for HCT in the zero-order absorption spectra were selected to construct the least squares calibration (CLS). Both graphical and numerical methods developed in this study were completely validated and applied to the quantitative analysts of tablets containing QA and HCT The results obtained from the developed methods were compared with each other as well as to those obtained by classical derivative spectrophotometry, which have different experimental conditions than the previous derivative method, and the difference was not observed statistically significant.Article Citation - WoS: 5Citation - Scopus: 5Spectral Continuous Wavelet Transform for the Simultaneous Spectrophotometric Analysis of a Combined Pharmaceutical Formulation(Chiminform Data S A, 2009) Dinc, Erdal; Baleanu, Dumitru; Baleanu, Dumitru; MatematikContinuous wavelet transform (CWT) combined with zero crossing technique was proposed for the simultaneous spectrophotometric determination of telmisartan (TMS) and hydrochlorothiazide (HCT) in their binary mixtures without using a chemical pretreatment. This new hybrid analytical approach is based on the application of the CWT method to the absorption spectra of the analytes and their samples. In the signal analysis, Gaussian (GAUS3) with order 3 and BiorSplines (BIOR1.2) with 1.2 order were found to be suitable for the quantitative spectral resolution of TMS and HCT in samples. These hybrid approaches were named as GAUS3-CWT and BIOR1.2-CWT The validation of the CWT signal processing methods was carried out by using various binary mixtures of the analytes. The amounts of TMS and HCT in tablets were successfully determined by using the proposed GAUS3-CWT and BIOR1.2-CWT tools.Article Simultaneous Determination of Hydrochlorotiazide and Olmesartan Modoxomil in a Binary Mixture by the Calibrations of the Spectral Linear Regression Equations(Chiminform Data S A, 2012) Dinc, Erdal; Baleanu, Dumitru; Buker, Eda; Baleanu, Dumitru; MatematikTwo new approaches were proposed for the quantitative analysis of the commercial samples consisting of hydrochlorotiazide (HCT) and olmesartan modoxomil (OLM). The proposed bivariate calibration (BC) and multivariate linear regression calibration (MLRC) methods are based on the simultaneous use of the linear regression equations for each compound. The UV absorption spectra of calibration solutions in the linear concentration range of 1.0-16.0 mu g/mL for both HCT and OLM were recorded between the 200-300 nm wavelength regions. The individual linear regression equations of the subjected compounds were obtained by using the relationships between the concentration and absorbance values at the 62 wavelength points with the interval of 1.0 nm from 218 nm to 279 nm. The BC and MLRC model based linear regression equations were validated by analyzing the binary mixture samples containing HCT and OLM in the different concentration compositions. The proposed BC and MLRC approaches were found to be accurate, precise and rapid for the simultaneous determination of HCT and OLM in combined dosage form.Article Citation - WoS: 3Citation - Scopus: 4Spectrophotometric Determination of Ramipril and Hydrochlorothiazide in a Mixture(Asian Journal of Chemistry, 2011) Dinc, Erdal; Baleanu, Dumitru; Baleanu, Dumitru; MatematikDouble wavelet transforms based on the use of continuous wavelets transform (CWT) and discrete wavelets transform (DWT) were proposed for the simultaneous quantification of hydrochlorothiazide and ramipril in tablets. DMEY-CWT was applied to the simultaneous quantitative resolution of the overlapping spectra of the UV spectra of the related compounds and their two-component mixtures. After that DMEY-CWT spectra were processed by BIOR3.5-DWT due to the noises and fluctuations coming from instrumentation and experimental media, respectively, to obtain the smoothing and denosing double transformed signals. Calibration graphs for ramipril and hydrochlorothiazide were obtained by measuring the double transformed wavelet amplitudes at 254.1 and 246.4 nm in the spectral region 230.0 and 281.1 nm, respectively. The validation of the continuous wavelets transform signal processing method was performed on the recovery study. The proposed method was successfully applied to the commercial tablets containing two compounds and good accuracy and precision were reported.Article Citation - WoS: 2Citation - Scopus: 3An Application of Principal Component Analysis - Artificial Neural Network for the Simultaneous Quantitative Analysis of a Binary Mixture System(Chiminform Data S A, 2009) Dinc, Erdal; Baleanu, Dumitru; Sen Koktas, Nigar; Köktaş, Nigar; Baleanu, Dumitru; Kökias, Nigar Şen; MatematikArtificial neural networks (ANNs) based on the use of principal components and the original absorbance data were proposed for the simultaneous quantitative analysis of amlodipine (AML) and atorvastatin (ATO) in tablets. A concentration set of mixtures containing ATO and AML in different concentration composition between 0.0-20.0 mu g/mL was prepared in methanol. The measured absorbance data matrix for the concentration data set was obtained and the principal components were extracted. In the next step five principal components were selected as an input data for the artificial neural network. This combined approach was named principal components-artificial neural network (PCA-ANN). The same problem was solved by using the application of the artificial neural network to the original absorbance data matrix. This approach was denoted as ANN. The classical ANN approach was used as a comparison method. Both PCA-ANN and ANN methods were tested by analyzing various synthetic mixtures corresponding to the validation set of AML and ATO compounds. The proposed methods were successfully applied to the quantitative analysis of the commercial tablets and a coincidence was reported between the proposed methods.Article Citation - WoS: 1Citation - Scopus: 1Ultra Performance Liquid Chromatography for the Rapid Determination of Allura Red in a Commercial Liquid Drink(Chiminform Data S A, 2011) Dinc, Erdal; Baleanu, Dumitru; Buker, Eda; Baleanu, Dumitru; MatematikA new ultra performance liquid chromatographic (UPLC) method was developed for the rapid determination of allura red in a commercial liquid drink. Chromatographic separation and quantitation of allura red were accomplished on an Acquity UPLC (TM) BEH C(18) (50 mm x 2.1 mm, 1.7 mu m) column system using an isocratic elution with a mobile phase consisting of acetonitrile and acetic acid with 3 % triethylamine (20:80: v/v) at a constant flow rate, 0.4 mL/min. Chromatographic calibration graph for allura red in the linear concentration range of 1.0-10.0 mu g/mL was calculated by using the linear least square regression analysis based on the relationship between the concentration and the peak area with photodiode array detection at the wavelength 510 nm. The UPLC method was validated by using the standard addition technique and successfully applied to the UPLC quantitation of the commercial liquid drinking samples. We conclude that a good agreement of UPLC quantitation results was reported.Article Citation - WoS: 1Citation - Scopus: 2Wavelet Transform With Chemometrics Techniques for Quantitative Multiresolution Analysis of a Ternary Mixture Consisting of Paracetamol, Ascorbic Acid and Acetylsalicylic Acid in Effervescent Tablets(Chiminform Data S A, 2006) Baleanu, Dumitru; Dinc, Erdal; Ozdemir, Abdil; Taş, Kenan; Baleanu, Dumitru; Tas, Kenan; MatematikQuantitative multiresolution analysis of paracetamol (PAR), ascorbic acid (AA) and acetylsalicylic acid (ASP) in pharmaceutical samples was carried out by using simultaneous use of discrete wavelet transformation (DWT) and afterward partial least squares (PLS) and classical least squares (CLS) techniques. The desired concentration was obtained using a set of 20 different calibration samples of PAR, AA, and ASP in different concentration ratio. The absorption spectra in the spectral range of 220-305 nm were recorded and their absorption values were measured at 850 points with intervals of Delta lambda = 0. 1 nm. The obtained DWT-CLS and DWT-PLS calibrations were tested by analysing the independent synthetic mixture containing the above subject compounds. The experimental results showed that DWT-CLS and DWT-PLS techniques are suitable for simultaneous determination of PAR, AA and ASP in samples. The obtained results were compared with those in literature.Article Citation - WoS: 16Citation - Scopus: 13Wavelet Transform and Artificial Neutral Network for the Quantitative Resolution of Ternary Mixtures(Revista Chimie Srl, 2006) Dinc, Erdal; Baleanu, Dumitru; Baleanu, Dumitru; Tas, Aysegul; MatematikTwo different approaches continuous wavelet transform (CWT) and artificial neural network (ANN) were successfully applied to the quantitative resolution of ternary mixtures of paracetamol (PAR), metamizol (MET) and caffeine (CA) having strongly overlapping spectra. First approach is based on the use of CWT signals of the ratio spectra of three active compounds in samples. Various CWT families were tested for the extraction of cardinal information and small noise condition and higher peaks of the original spectra. In this paper, three methods: Mexican hat function (MEX) (a = 70), reverse biorthogonal (RBIO3.5) (a = 100) and biorthogonal (BIOR2.4) (a = 90) were found suitable for determination of three active compounds and their signal analysis. ANN, as a multivariate numerical method, was used for the quantitative resolution of the same ternary mixtures. The performance of CWT and ANN approaches was validated by analyzing the synthetic mixtures of PAR, MET and CA compounds. In addition, the standard addition technique was also used for the same purpose. The experimental results provided by CWT technique were compared with each other and those obtained by ANN method and a coincidence was observed for all the obtained results.