12 research outputs found
Preconcentration of Aluminum on Nano ZrO2/B2O3 and Its Determination by Flame Atomic Absorption Spectrometry
12th National Spectroscopy Congress -- MAY 18-22, 2011 -- Antalya, TURKEYWOS: 000303588400006This study presents a chelating agent free solid phase extraction method for preconcentration of Al(III) using hybrid nano zirconium dioxide-boron oxide (ZrO2/B2O3) sorbent. This method is based on the sorption of Al(III) ions directly onto nano sorbent, followed by the elution with 10 mL of 4 mol L-1 HNO3 and determination by flame atomic absorption spectrometry (FAAS). Preconcentration parameters, including pH of the sample solution, volume and concentration of the eluent, sample volume, and flow rate of the sample solution, that affect the recovery of the Al(III) ions have been optimized. Under the optimized experimental conditions, analytical parameters such as limit of detection, limit of quantification, linear working range, precision, and accuracy were determined. The analytical limit of detection for Al(III) was found as 7.71 mu g L-1. The reusability and adsorption capacity of the new hybrid sorbent for Al(III) ions were also investigated. Interfering effects of matrix constituent on the recovery of the Al(III) ions were studied. The accuracy of the method was checked by determining Al(III) ions in a certified reference water sample (SPS-WW1 Waste Water). The proposed procedure was applied for the determination of Al(III) ions in dam waters.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [110T111]This work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK, Project No. 110T111)
Application of full factorial design for the preconcentration of chromium by solid phase extraction with Amberlyst 36 resin
5th Aegean Analytical Chemistry Days Conference -- OCT 05-08, 2006 -- Thessaloniki, GREECEWOS: 000255126900002The preconcentration of chromium(III) by solid phase extraction and its determination from aqueous solutions by flame atomic absorption spectrometry (FAAS) is investigated by applying an experimental design. The optimization of the preconcentration variables such as pH of the sample solution, flow rate of the sample solution and concentration of elution solution was carried out using 2(3) full factorial design. The most important parameter affecting the preconcentration of chromium is the concentration of eluent. In the established experimental conditions, chromium can be determined with a relative standard deviation of 2.0% (N = 7) for a chromium concentration of 100 mu g L-1. The detection limit for chromium was 1 mu g L-1 (N= 20). The adsorption capacity of Amberlyst 36 is found to be 90.9 mg g(-1) for chromium. Effect of other ions on the procedure was also evaluated. The method was validated by the analysis of certified reference materials (tea leaves GBW 07605 and fish tissue IAEA-407). The method was applied to the determination of chromium in waste water, dam water, carrot, parsley and lettuce
A Solid Phase Extraction Application of Hybrid Nano B2O3/ZrO2 for Separation and Determination of Trace Indium in Environmental Samples
WOS: 000430996100049Hybrid nanomaterials have attracted considerable interest in environmental science, analytical chemistry and atomic spectroscopy. In the present study, a column solid phase extractioo procedure was developed for the separation and preconcentration of indium in various matrixes by using hybrid nanomaterial B2O3/ZrO2 (HNMBZ). Various experimental and analytical parameters such as sample solution pH, sample solution volume, flow rate of sample solution and eluent, volume and concentration of eluent and amount of HNMBZ, effect of common matrix ions and capacity of sorbent were investigated. The adsorbed metal ions on HNMBZ were eluted with 6 mL of 1 mol . L-1 HNO3 solutions and their concentrations were determined by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Under the optimized conditions, detection limits for indium for 3 pixels and 5 pixels were found as 0. 20 and 0. 16 mu g . L-1, respectively. The accuracy of the procedure was checked by spiked water samples. The developed procedure was successfully applied to real samples for the separation and determination of indium.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [110T111, 214Z221]the Scientific and Technological Research Council of Turkey (TUBITAK Grants no. 110T111, 214Z221
HEAVY METAL BIOSORPTION OF COPPER IONS BY IMMOBILIZED BIOMASS OF STICHOCOCCUS SUBTILIS (KUTZING) KLERCKER
WOS: 000413499500011In this study, the ability of Stichococcus subtilis (Kiitzing) Klercker was used for heavy metal removal adsorbstion capacity. The sorption ability of S. subtilis was investigated using Cu metallic solutions. In the analysis, pH effect, equilibrium timing, initial metal ions concentration and temperature ranges were investigated. For single metal systems, sorption isotherms were well-fitted to the Langmuir model. The results of the maximum Cu biosorption capacities were found as 2.70 and 10.4 mg/g for alginate and alginate cells, with pH 5.5, corresponding to the initial Cu concentration of 50 mg/L. Cu biosorption on all the tested biosorbents agreed with Langmuir adsorption isotherm model
High-resolution continuum source flame atomic absorption spectrometric (HR-CS FAAS) determination of trace aluminium and lead in water and some beverage samples after separation and preconcentration procedure
WOS: 000334065100004In the present study, a solid phase extraction procedure has been presented for the separation and preconcentration of aluminium (Al) and lead (Pb) in various matrixes such as water, cola and fruit juice samples. 4-[(3-amino-5-{[(2-hydroxyphenyl) methylidene] amino}-1H-pyrazol-4-yl) diazenyl] benzoic acid (AHPMAPDAB) was used as a ligand. AHPMAPDAB chelates of Al and Pb ions in aqueous solutions were adsorbed on polystyrene-graft-ethyl methacrylate copolymer (Poly S-15-g-EMA(120)). Various experimental and analytical parameters such as sample solution pH, sample volume, flow rate of sample solution and eluent, volume and concentration of eluent, amount of ligand and adsorbent, effect of common matrix ions and capacity of adsorbent were investigated. The adsorbed metal ions on resin were eluted with 6mL of 2molL(-1) HCl solutions and their concentrations were determined by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Under the optimised conditions, limits of detections were 0.32 mu gL(-1) and 0.24 mu gL(-1) for Al and Pb, respectively. The accuracy of the procedure was confirmed by analysing certified materials (NIST SRM 1643e, Trace elements in water) and spiked real samples. The developed procedure was successfully applied to real samples.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [110T111]We would like to thank the Scientific and Technological Research Council of Turkey (TUBITAK grant no. 110T111). The authors are also grateful to Prof. Dr. Memet Sekerci for ligand synthesis
A low energy HEVC inverse transform hardware
In this paper, a novel energy reduction technique for High Efficiency Video Coding (HEVC) Inverse Discrete Cosine Transform (IDCT) and Inverse Discrete Sine Transform (IDST) for all transform unit (TU) sizes is proposed. The proposed technique calculates IDCT and IDST only for DC coefficient if the values of several predetermined forward transformed low frequency coefficients in a TU are smaller than a threshold. The proposed technique reduces the computational complexity of IDCT and IDST significantly. It increases the bit rate slightly for most video frames. It decreases the PSNR slightly for some video frames, and it increases the PSNR slightly for some video frames. In this paper, a low energy HEVC 2D inverse transform (IDCT and IDST) hardware for all TU sizes is also designed and implemented using Verilog HDL. In the worst case, the proposed hardware can process 48 Quad HD (3840x2160) video frames per second. The proposed technique reduced the energy consumption of this hardware up to 32%. Therefore, the proposed hardware can be used in portable consumer electronics products that require a real-time HEVC encoder.(1
A low energy HEVC inverse DCT hardware
In this paper, a novel energy reduction technique for High Efficiency Video Coding (HEVC) Inverse Discrete Cosine Transform (IDCT) for all Transform Unit (TU) sizes is proposed. An efficient HEVC 2D IDCT hardware for all TU sizes is also designed and implemented using Verilog HDL. The proposed hardware can decode 48 Quad HD (3840×2160) video frames per second. The proposed technique reduced its energy consumption up to 23%
Inhibitory effects of ticlopidine and clopidogrel on the intimal hyperplastic response after arterial injury
Objective: The purpose of this study was to compare the effects of ticlopidine and clopidogrel on the development of neointimal hyperplasia after experimental arterial injury