Matematik Bölümü Yayın Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/413

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Browsing Matematik Bölümü Yayın Koleksiyonu by Author "105547"

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    Citation Count: Üstündağ, Ö., Dinç, E., Baleanu, D. (2008). Applications of Mexican Hat Wavelet Function to Binary Mixture Analysis. Revista De Chimie, 59(12), 1387-1391.
    Applications of Mexican Hat Wavelet Function to Binary Mixture Analysis
    (Chiminform Data S A, 2008-12) Üstündağ, Özgür; Dinç, Erdal; Baleanu, Dumitru; 105547; 6981; Çankaya Üniversitesi, Fen Edebiyat Fakültesi, Matematik Bilgisayar Bölümü
    The simultaneous determination of pyridoxine hydrochloride (B6) and isoniazide (INH) in tablets was performed by using the Mexican hat wavelet function (MEXH). The absorption spectra of B6, INH and their samples were recorded in the spectral range of 200-330 nm. Linear regression functions for B6 and INH in the linear concentration range of 5-45 mu g/mL were obtained by measuring the transformed signals at 253.5 nm corresponding to the zero-crossing point for INH and at 270.6 nm corresponding to the zero-points for B6, respectively. The validation of MEXH method was performed by using the synthetic mixtures. The percent mean recoveries and their relative standard deviations were found as 98.7% and 2.06 for B6 and 98.9% and 1.89 for INH in the synthetic mixture analysis. The MEXH method was applied to the real samples and a good sensitivity and selectivity was reported. The MEXH method was sucessfully compared with classical derivative method
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    Citation Count: Dinç, E...et al. (2006). "Chemometric determination of naproxen sodium and pseudoephedrine hydrochloride in tablets by HPLC", Chemical & Pharmaceutical Bulletin, 54(4), 415-421.
    Chemometric Determination of Naproxen Sodium and Pseudoephedrine Hydrochloride in Tablets by HPLC
    (Pharmaceutical Soc Japan, 2006-04) Dinç, Erdal; Özdemir, Abdil; Aksoy, Halil; Üstündağ, Özgür; Baleanu, Dumitru; 6981; 26096; 105547; Çankaya Üniversitesi, Fen Edebiyat Fakültesi, Matematik Bilgisayar Bölümü
    A new chemometric determination by high-performance liquid chromatography (HPLC) with photodiode array (PDA) detection was implemented for the simultaneous determination of naproxen sodium and pseudoephedrine hydrochloride in tablets. Three chemometric calibration techniques, classical least squares (CLS), principle component regression (PCR) and partial least squares (PLS) were applied to the peak area at multiwavelength PDA detector responses. The combinations of HPLC with chernometric calibration techniques were called HPLC-CLS, HPLC-PCR and HPLC-PLS. For comparison purposes the HPLC method called the classic HPLC method was used to confirm the results obtained from combined HPLC-chemometric calibration techniques. A good chromatographic separation between two drugs with losartan potassium as an internal standard was achieved using a Waters Symmetry (R) C18 Column 5 mu m 4.6 +/- 250 mm and a mobile phase containing 0.2 m acetate buffer and acetonitrile (v/v, 40 : 60). The multiwavelength PDA detection was measured at five different wavelengths. The chromatograms were recorded as a training set in the mobile phase. Three HPLC-chemometric calibrations and the classic-HPLC method were used to test the synthetic mixtures of naproxen sodium and pseudoephedrine hydrochloride in the presence of the internal standard. The HPLC-chemometric approaches were applied to real samples containing drugs of interest. The experimental results obtained from HPLC-chemometric calibrations were compared with those obtained by a classic HPLC method
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    Citation Count: Dinç, E...et al. (2006). Discrete and continuous wavelet transforms for the multicomponent determination of sunset Yellow and tartrazine in their soft drink powders. Revista De Chimie, 57(1), 29-35.
    Discrete and continuous wavelet transforms for the multicomponent determination of sunset Yellow and tartrazine in their soft drink powders
    (Chiminform Data S A., 2006-01) Dinç, Erdal; Baleanu, Dumitru; Üstündağ, Özgür; Aboul-Enein, Hassan T.; 6981; 105547; Çankaya Üniversitesi, Fen Edebiyat Fakültesi, Matematik Bilgisayar Bölümü
    The multicomponent quantitative resolution of the binary mixtures containing, sunset Yellow (SN) and tartrazine (TR) without any pre-chemical treatment, in the presence of the overlapping signals was accomplished by the simultaneous use of the discrete and the continuous wavelet transform (CWT) followed by a zero crossing technique. We propose G transformation approach of signals in wavelet domain, based on both one-dimensional CWT and zero-crossing technique for obtaining a higher resolution of the binary mixtures. The application of this approach contains three steps: firstly, UV-recorded spectra were transferred into the wavelet domain and were subject to the one-dimensional discrete wavelet transform for obtaining an appropriated de-noising signal; secondly, CWT was applied on the de-noising signal and a new transformed signal was obtained so that it contains many zero-crossing points and higher peaks.; thirdly, a zero-crossing technique was applied to the transformed signal obtained in step two, The calibration graphs were drawn by choosing a one-dimensional continuous family, namely, Symlets2 (SYM2) and Gauss3 (GAUS3) followed by a zero-crossing technique. The quantitative analysis of the commercial product containing the above colorants was carried out by using this approach and successful results were obtained.
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    Citation Count: Dinç, E...et al. (2006). Simultaneous determination of tartrazine and allura red in commercial preparation by chemometric HPLC method. Journal of Food and Drug Analysis, 14(3), 284-291
    Simultaneous determination of tartrazine and allura red in commercial preparation by chemometric HPLC method
    (Natl Laboratorıes Foods Drugs, 2006-09) Dinç, Erdal; Aktaş, A. Hakan; Baleanu, Dumitru; Üstündağ, Özgür; 6981; 17107; 105547; Çankaya Üniversitesi, Fen Edebiyat Fakültesi, Matematik Bilgisayar Bölümü
    The concentrations of tartrazine (TAR) and allura red (ALL) in binary mixtures and commercial preparation were determined by the combined use of chemometric (or multivariate) calibrations and HPLC method. In this study, partial least squares (PLS), principal component regression (PCR) and classical least squares (CLS) based on multiwavelength HPLC data were refined as multivariate calibration techniques such as CPLS, CPCR, CCLS. The relation between multiwavelength peak area data (x-block) and concentration set (y-block) were used to obtain the chromatographic multivariate calibrations. Multiwavelength-chromatograms or multiwavelength peak area data were obtained by using photodiode array (PDA) detectors. Waters Symmetry (R) C18 Column 5 mu m 4.6 x 250 mm and a combination of 0.2 M acetate buffer (pH = 5), acetonitrile, methanol and bidistilled water (55:20:10 v/v) at the flow rate of 1.9 mL/min were used to obtain a good chromatographic separation between TAR and ALL in presence of sunset yellow (Internal Standard (IS)). These chromatographic multivariate techniques were validated by analyzing the different synthetic mixtures and by using standard addition technique. These methods were applied to the commercial soft drinking powder samples containing TAR and ALL. The results from these chromatographic multivariate techniques were compared with each other as well as obtained by alternative single HPLC method