TR Dizin İndeksli Yayınlar / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7149
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Article Development of Chemometrics Method Based on Infrared Spectroscopy for the Determination of Cement Composition and Process Optimization [article](ACG Publications, 2022) Özdemir, Durmuş; Gümüş, Mehmet Gökhan; Tepeli, DilekIn combination with a multivariate calibration method, FTIR-ATR spectroscopy was presented as a rapid method for the determination of some major oxides (CaO, SiO2, Al2O3, Fe2O3) and minor oxides (MgO, SO4, Na2O, and K2O) in diverse materials (raw material, raw meal, additives, clinker, and types of cement) in cement manufacturing. The FTIR spectroscopy based multivariate models were generated by taking X-ray fluorescence (XRF) as a reference method. Among a number of spectral preprocessing methods, extended multiplicative scatter correction (EMSC) yielded the best PLS models. The standard error of prediction (SEP) for the optimal FTIR based PLS models ranged from 0.10 to 2.07 (w/w%), and the regression coefficient (R2) ranged from 0.95 to 0.99 for PLS predicted vs XRF reference plots. Statistical evaluation of the both methods was carried out by paired t-test at the 95% confidence level and the results showed that the FTIR-ATR combined with PLS model results are consistent with the XRF reference measurements for all the oxides studied. Compared to the XRF method, which can take anywhere from a few minutes to an hour for each measurement, the proposed method is faster, cheaper, and safer. The presented technology also allows rapid monitoring of a cement factory production line.Article Citation - WoS: 6Citation - Scopus: 6Benzodiazepine Derivatives From Marine-Derived Streptomyces Cacaoi 14cm034(ACG Publications, 2021) Çetinel Aksoy, Semiha; Küçüksolak, Melis; Uzel, Ataç; Bedir, Erdal7-methoxy-8-hydroxy cycloanthranilylproline (2), a new natural product with pyrrolobenzodiazepine (PBD) framework, was isolated from marine-derived actinobacterium Streptomyces cacaoi 14CM034, together with cycloanthranilylproline (1). Structural elucidation of the compounds was based on FTIR, 1D-(H-1 and C-13 NMR), 2D-NMR (COSY, HMBC and NOESY) and HR-MS analyses. Compounds 1 and 2 exhibited notable antimicrobial activity. The presence of PBD derivatives in S. cacaoi was first demonstrated with this study.Article Citation - WoS: 8Citation - Scopus: 8Simple High-Performance Liquid Chromatographic Method for Determination of Donepezil Hcl in Pharmaceutical Formulations(ACG Publications, 2020) Bulduk, İbrahim; Aydın, Beyza SultanDonepezil HCl is a hydrochloride salt of a piperidine derivative acetylcholinesterase inhibitor and, it uses in treatment demantia of Alzheimer’s disease. In this study, a sensitive and rapid HPLC-UV method was developed and validated for determination of Donepezil HCl in API and tablet dosage forms. Chromatographic separation was performed using a Ace 5 C18 (5 ?m, 250 x 4.6 mm) by using isocratic phosphate buffer at pH:2.0 and acetonitrile (55:45, v/v) mobile phase was used at the rate of 1.2 mL/min. The column temperature was set at 30 ?C and the UV detection was recorded at 268 nm. The method was validated with respect to specificity, precision, accuracy, linearity, repeatability and reproducibility parameters in a concentration range of 25-125 µg/mL. The limit of detection (LOD) and limit of quantification (LOQ) were determined as 1.40 and4.20 µg/mL, respectively. The uncertainty budget of the measurement for Donepezil HCl was estiamted as 5.80 % at 95% confidence level (k = 2).