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Öğe Determination of mineral and trace elements in some medicinal herbs and their infusions consumed in Turkey(Elsevier, 2006) Basgel, S; Erdemoglu, SBFourteen mineral and trace elements (Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sr and Zn) were determined in the herbs and their infusions consumed for medical purposes in Turkey such as chamomile (Matricaria chammomile L.), fennel (Foeniculum vulgare), linden (Tilia vulgaris), nettle (Urtica dioical), rosehip (Fr.Rosa caninae), sage (Salvia officinalis) and senna tea (Cassia anqustifolia). Microwave digestion procedure was applied under optimized conditions for dissolution of medicinal herbs. Element concentrations in the medicinal herbs and their infusions were determined by FAAS and ICP-AES. The accuracy and precision were verified against a GBW 07605 Poplar leaves and Tea certified reference material. The mineral and trace element content of medicinal herbs and their infusions showed a wide variability. However, distribution of the elements in the infusions is not high and it is nil especially for Cd, Co, Cr and Pb. (C) 2005 Elsevier B.V. All rights reserved.Öğe Determination of total and fluoride bound aluminium in tea infusions by ion selective electrode and flame atomic absorption spectrometry(Marcel Dekker Inc, 2000) Erdemoglu, SB; Türkdemir, H; Güçer, SSpeciation of metallic compunds is important especially for their bioavailability. In this present study fluoride bound aluminium species were determined in tea infusion. Total aluminium was measured using name atomic absorption spectrometry (FAAS). Free fluoride and total fluoride were measured by fluoride selective ion electrode (FISE) with the assistance of TISAB buffer solution used for adjustment of pH and total ionic strength, and ALCOA buffer solution which decomposes all of the Al-fluoride complexes in solution. During the studies, the effects of pH and time on the formation of Al-F complexes and interference of some metal ions found in tea infusion such as Al3+, Mg2+, Fe2+, Fe3+ and Mn2+ on the concentration of free fluoride were investigated. The concentration of each Al-fluoride complexes in tea infusion were determined indirectly by calculation using pF-Mole Fraction Diagram. It was found that 1.13+/-0.15 mg l(-1) of 12.00+/-0.86 mg l(-1) total aluminium is fluoride bound aluminium, which means that approximately 10% of total aluminium in tea infusion is complexed with fluoride.Öğe Optimisation of microwave digestion for determination of Fe, Zn, Mn and Cu in various legumes by flame atomic absorption spectrometry(Wiley, 2006) Erdogan, S; Erdemoglu, SB; Kaya, SFe, Zn, Mn and Cu levels in three Turkish legumes, kidney bean (Phaseolus vulgaris L.), lentil (Lens esculenta) and chickpea (Cicer avietinum), were determined by flame atomic absorption spectrometry. Dissolution conditions in the microwave-assisted wet digestion method were studied by investigating several variables, including type of acid mixture, acid volume, digestion time, microwave power input and sample weight. Comparison with conventional wet acid digestion was also made. In order to check the element losses during digestion and the accuracy of the results, all tests were repeated after the addition of a spiked standard element solution to the legume sample. The microwave-assisted digestion procedure optimised for kidney bean was adapted for lentil and chickpea. Fe, Zn, Mn and Cu concentrations (mg per 100 g sample) were determined in kidney bean as 6.27 +/- 0.94, 2.23 +/- 0.36,1.64 +/- 0.14 and 0.99 +/- 0.19, in lentil as 8.24 +/- 1.11, 2.46 +/- 0.06, 1.17 +/- 0.19 and 1.01 +/- 0.28 and in chickpea as 6.00 +/- 1.40, 2.21 +/- 0.14, 1.60 +/- 0.43 and 0.58 +/- 0.18 respectively. (c) 2005 Society of Chemical Industry.Öğe Selective determination of aluminum bound with tannin in tea infusion(Japan Soc Analytical Chemistry, 2005) Erdemoglu, SB; Güçer, SIn this study, an analytical method for indirect measurement of Al bound with tannin in tea infusion was studied. This method utilizes the ability of the tannins to precipitate with protein. Separation conditions were investigated using model solutions. This method is uncomplicated, inexpensive and suitable for real samples. About 34% of the total Al in brew extracted from commercially available teas was bound to condensed and hydrolyzable tannins.Öğe Speciation of aluminum in tea infusion by ion-exchange resins and flame AAS detection(Elsevier Science Bv, 2000) Erdemoglu, SB; Pyrzyniska, K; Güçer, SIn this study, it was attempted to fractionate aluminum that bound to hydrolyzable polyphenols and its cationic species, and to determine their concentrations in tea infusion by using ion exchange resins and flame AAS detection. In order to separate the hydrolyzable polyphenols bound aluminum species Amberlite XAD-7 resin was used while Chelex-100 resin was used to separate cationic aluminum species. For separation of aluminum species, after the optimization study based on the model solutions, the effluent from column filled with Amberlite XAD-7 was pumped directly through the column filled with Chelex-100 resin. Aluminum in all effluents was determined by FAAS method. It was found that about 30% of aluminum from black tea leafs transfers into the infusion that contains 11-12 mg l(-1) of Al and that about 10-19% of total aluminum in tea infusion is present as cationic species, while about 28-33% of as hydrolyzable polyphenols bound aluminum. (C) 2000 Elsevier Science B.V. All rights reserved.Öğe The synthesis and application of new adsorbents for removal of heavy metal ions and phenols from aqueous solution(Parlar Scientific Publications (P S P), 2003) Sener, S; Sayilkan, F; Erdemoglu, SB; Akarsu, M; Sayilkan, HIn this study, a TiO2 adsorbent powder was synthesized from Titan (IV)-n-propoxyallyl acetoacetate by the sol-gel process. This powder and its coated forms (SH-and NH2- functional silanes) were investigated for their phenol, p-chlorophenol, Cu2+, Ph2+ and Zn2+ adsorption. It was found that Pb2+ and Zn2+ adsorption on the adsorbent coated with NH2-functional silane and Cu2+, Pb2+ adsorption on the adsorbent coated with SH-functional silane were nearly complete.
