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The aim of this study is to investigate the perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) levels in patients with different stages of chronic kidney disease (CKD). Sixty-one CKD stage 1-4 patients who applied to the nephrology outpatient clinic were recruited. A control group consisting of 26 age- and sex-matched healthy controls were also included in the study. Concentrations of PFOA and PFOS were determined by comparing their peak areas with their standard curves. All samples were analyzed three times. The average values of blank samples were subtracted from the detected PFOA and PFOS values. PFOA and PFOS levels were significantly higher in CKD group than the controls (11.4 ± 7.47, 0.45 ± 0.55; 0.13 ± 0. 17, 0.19 ± 0.4 ng/mL, respectively) (P = 0.001). Hemoglobin, serum albumin, and estimated glomerular filtration rate (eGFR) levels were significantly lower and potassium and uric acid levels were higher in the CKD group than the controls. PFOA and PFOS levels were significantly higher in all stages of CKD patients than healthy controls. However, there was no correlation between eGFR, and PFOS and PFOA. We have demonstrated significantly increased PFOA and PFOS concentrations in different stages of CKD patients. We could not find an association between eGFR, age, and serum PFOS and PFOA concentrations.

The main function of food packaging is to delay natural processes that lead to food spoilage. To this end, antioxidants are often included in food packaging materials during processing and released into packaged food through a controlled diffusion mechanism. The use of antioxidants in food packaging helps delay both lipid oxidation and protein denaturation. In recent years, natural antioxidant packages have been preferred in food packages rather than synthetic ones. In this study, it was aimed to determine the effect of using packaging containing natural antioxidant essential oils on delaying the decay time of Clarias gariepinus. Films containing natural antioxidant essential oils (Thymus sp., Mentha piperita, Foeniculum vulgare, Laurus nobilis, Fructus cumini) were prepared. Then, the effect of prepared films on the chemical quality of C. gariepinus was investigated during refrigerated storage for 15 days. The preservative effect of films was assessed periodically by a free fatty acid, thiobarbituric acid value, peroxide value, and total sulfhydryl content analyses. Obtained results showed that the use of active packaging films containing natural antioxidant essential oils improved the oxidative stability of C. gariepinus.

Polymer-supported pendant urea groups have been demonstrated to be very efficient in selective removal of mercuric ions from aqueous solutions. Methyl methacrylate (0.5 mol)-glycidyl methacrylate (0.4 mol)-divinylbenzene (0.1 mol) terpolymer beads have been prepared by suspension polymerisation. Urea functions have been incorporated into the bead polymer (210-420 mum) via a two-step modification of the epoxy groups involving firstly reaction with excess of triethylenetetramine followed by acidic isocyanate. The resulting polymer resin has a urea group loading of 7.8 mmol g(-1) and shows excellent mercury binding capacity > 6.7 mmol g(-1) even in the presence of excess chloride ions. The mercury sorption is strictly selective and Ca(II) Mg(II) Zn(H) Pb(II) Fe(II) and Cd(II) ions (0.2-0.3 M) do not give rise to any interference. The mercury can be recovered from loaded beads using hot acetic acid thereby regenerating the polymer. Recovered samples can be recycled more than 20 times without loss of activity as a result of the hydrolytic stability of the urea group in acetic acid. (C) 2002 Elsevier Science B.V. All rights reserved.

N-octyl methane sulfonamide (OMSA) has been demonstrated to be a very efficient reagent for selective extraction of Hg(II) ions from aqueous solutions. The extraction bases on rapid reaction of OMSA with Hg(II) ions yielding mono and disulfonamido mercury compounds in ordinary conditions. Solubility of OMSA and its mercury compounds in 2-ethyl hexanol provide a clear-cut phase separation in the extraction. The solution of OMSA in 2-ethyl hexanol (0.4 mol L-1) is able to extract 82.2% of mercuric-acetate (0.4 mol L-1) in non-buffered conditions. Although the process depends on the nature of accompanying anions the distribution coefficient is reasonably high (k(d) greater than or equal to 1.27) even in the presence of chloride ions. The extraction is strictly selective and the presence of Cd(II) Zn(II) Pb(II) do not bring any interference. The extraction system works in moderate concentrations. Extracted mercury in the organic phase can be recovered by back-extraction with concentrated HCl or H2SO4 solutions. After acid treatment the organic solution of OMSA becomes regenerated without losing its activity due to reasonable hydrolytic stability of the sulfonamide linkage and it can be recycled for further extractions.

A new method for depositing metal onto a polymer surface has been developed in which the metal coating of polymer beads is performed with hydrazine functions as reducing agents on the surface of the polymer itself. In this study, glycidyl methacrylate–methyl methacrylate–divinyl benzene terpolymer was prepared as spherical beads with a suspension polymerization methodology. Beads of the polymer sample (210–420-μm fraction) containing 3.4 mmol g−1 epoxy were treated with an excess of hydrazinium hydroxide to yield a polymer with 2.3 mmol g−1 hydrazine functions. The hydrazine functions on the polymer surfaces were efficient in metal reductions. Therefore, the modified bead polymer samples, when soaked in aqueous ammonia solutions of Ni(II), Ag(I), and Cu(II) ions (0.1 M), were covered rapidly by the corresponding zero-valent metal ions. Metal deposition took place almost quantitatively (ca. 4.5 mmol/g of the polymer) within 60 min of the contact times. The accumulations of metal were followed visually and occurred only on the polymer beads. There was no evidence that the reaction occurred within the solution. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 748–754, 2002; DOI 10.1002/pola.10158

The stability constants of the complexes formed between the rare earth metal ions and the anion of trimetaphosphoric acid have been determined at a temperature of 20 degrees C and an ionic strength of mu = 0.1 by the ion-exchange equilibrium method. The investigations indicate that stabilities of complexes increased from La to Lu. The highest and the lowest stability constant values (beta) were found to be 7.76 and 3.82 for Lu3+ and La3+ respectively.