Adsorption isotherms, kinetic and thermodynamic studies on cadmium and lead ions from water solutions using Amberlyst 15 resin.

Adsorption isotherms, kinetic and thermodynamic parameters for Cd(II) and Pb(II) ions in water solutions by using Amberlyst 15 resin were performed and evaluated by utilizing solid phase extraction method with the batch system at 298, 308, and 318 K. Flame atomic absorption spectrometry was utilized for absorbance measurements of Cd and Pb in solutions. The Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models, respectively were implemented to equilibrium results obtained. Experimental and theoretical monolayer adsorption capacities of resin for adsorptions of Cd(II) and Pb(II) by the Langmuir isotherm model were approximately the same and they were 120 and 116 mg/g for Cd(II) and Pb(II) ions, respectively at 318 K. Most appropriate kinetic model for adsorption of Cd(II) and Pb(II) on the resin was found as pseudo-second-order. Contact time and temperature for adsorption of analytes on the resin were optimized at 45 min and 298 K. Activation energies (Ea) and thermodynamic values (ΔG°, ΔH° and ΔS°) were determined and assessed. Results showed that adsorptions of Cd(II) and Pb(II) on Amberlyst 15 were spontaneous, exothermic, and chemical ion-exchange processes.

Evaluation of an Innovative and Sustainable Pre-Commercial Compound as Replacement of Fish Meal in Diets for Rainbow Trout during Pre-Fattening Phase: Effects on Growth Performances, Haematological Parameters and Fillet Quality Traits.

The aim of the study was to determine the potential and sustainable use of pre-commercial product ITTINSECT™ APS V1 as a major protein source in rainbow trout (Oncorhynchus mykiss) diets. A 60-day feeding experiment was conducted to potentially use ITTINSECT as fish meal replacement in the diets of rainbow trout. Five isonitrogenous in dry matter (38% crude protein) and isolipidic (15% crude lipid) diets were produced: a control diet (fishmeal-based) (ITT0) and four experimental diets replacing fishmeal by 25 (ITT25), 50 (ITT50), 75 (ITT75) and 100 (ITT100) %, with ITTINSECT™ APS V1. Triplicate tanks, containing 15 fish each (65.81 ± 1.26 g), were hand-fed to apparent satiation twice every day during the experiment. At the end of the feeding trial, significantly higher growth performance was observed in the group fed ITTM25 and ITTM50 diets. This performance was supported by growth-related gene expressions analyzed in muscle; significantly higher GH and IGF-I genes expression levels were determined in ITT25 and ITT50 when compared to control (ITT0) (p < 0.05). While no significant differences were found between the hematology values (p > 0.05), serum total protein, globulins and glucose levels were significantly different between experimental groups (p < 0.05). In addition to this, the immune-related genes such as TNF-α, IL8 and IL1-ß expression levels were determined to be significantly different (p < 0.05). In conclusion, in order to achieve the best growth performance in rainbow trout and enhance sustainable aquaculture practices, replacement of fish meal with up to 50% ITTINSECT™ APS V1 in diets for rainbow trout is suggested.

Cardiac Chamber Quantification by Echocardiography in Adults With Sickle Cell Disease: Need Attention to Eccentric Hypertrophy.

Introduction and aim Sickle cell anemia (SCA) is the most common hemoglobinopathy worldwide, and cardiovascular diseases are the most common causes of death. In these patients, cardiac remodeling begins from childhood and leads to sickle cell cardiomyopathy in the following years. Concentric hypertrophy and eccentric hypertrophy are known to predict early cardiac events. This study aims to reveal the relationship between cardiac remodeling types and survival in patients with SCA and investigate the factors that may affect left ventricular mass. Materials and methods A total of 146 patients with SCA were included in the study, and the left ventricular mass index (LVMI) and relative wall thickness (RWT) of the patients were calculated according to echocardiographic measurements, and the patients were categorized into normal, concentric remodeling (CR), concentric hypertrophy (CH), and eccentric hypertrophy (EH) groups. Results The median age of the patients is 32 (18-72). In logistic regression analysis, hemoglobin S (HbS) and ferritin levels were independent predictors for LVMI (p = 0.01 and p < 0.001, respectively). It was observed that 56 (38.4%) of the patients had normal left ventricles, 24 (16.4%) had CR, 21 (14.4%) had CH, and 45 (30.8%) had EH. 31 (21.2%) of the patients died. When we look at the survival curves, there was a statistically significant difference between the four groups (log-rank p < 0.001). It was observed that patients with EH were the group with the lowest probability of survival. Conclusion Cardiac death is one of the most common causes of death in patients with SCA. Early detection of cardiac disorders and starting treatment may be important in reducing mortality in these patients.

Solid Phase Extraction of Cadmium and Lead from Water by Amberlyst 15 and Determination by Flame Atomic Absorption Spectrometry.

Preconcentration of Cd(II) and Pb(II) was carried out by using column solid phase extraction method. Amberlyst 15 was used as solid phase for these analytes. The optimum extraction conditions such as pH (4), type and volume of eluent (5 mL of 2 mol L-1 HNO3) sample flow rate (1 mL min-1) and sample volume (100 mL for Cd(II) and 750 mL for Pb(II)) were determined. The recoveries were found for Cd(II) and Pb(II) as 104% ± 1% and 102 % ± 2%, respectively. The limit of detections were found as 0.23 µg L-1 for Cd(II) and 0.13 µg L-1 for Pb(II). The effects of foreign ions were also studied. The method was validated by analyzing standard reference material and spiked water samples. Percent relative error and relative standard deviation were below 3% and 4%, respectively.

Chelating agent free-solid phase extraction (CAF-SPE) of Co(II), Cu(II) and Cd(II) by new nano hybrid material (ZrO2/B2O3).

New nano hybrid material (ZrO(2)/B(2)O(3)) was synthesized and applied as a sorbent for the separation and/or preconcentration of Co(II), Cu(II) and Cd(II) in water and tea leaves prior to their determination by flame atomic absorption spectrometry. Synthesized nano material was characterized by scanning electron microscope, transmission electron microscope and X-ray diffraction. The optimum conditions for the quantitative recovery of the analytes, including pH, eluent type and volume, flow rate of sample solution were examined. The effect of interfering ions was also investigated. Under the optimum conditions, adsorption isotherms and adsorption capacities have been examined. The recoveries of Co(II), Cu(II) and Cd(II) were 96 ± 3%, 95 ± 3%, 98 ± 4% at 95% confidence level, respectively. The analytical detection limits for Co(II), Cu(II), and Cd(II) were 3.8, 3.3, and 3.1 µg L(-1), respectively. The reusability and adsorption capacities (32.2 mg g(-1) for Co, 46.5 mg g(-1) for Cu and 109.9 mg g(-1) for Cd) of the sorbent were found as satisfactory. The accuracy of the method was confirmed by analyzing certified reference material (GBW-07605 Tea leaves) and spiked real samples. The method was applied for the determination of analytes in tap water and tea leaves.

A new method for indirect determination of iodide and thiosulfate in table salt and milk based on a combination of solid-phase extraction and flame atomic absorption spectrometry.

A new indirect method for the determination of iodide and thiosulfate ions in table salt and milk by flame atomic absorption spectrometry was described. This method is based on the reduction of chromium (VI) to chromium(III) with the reducing action of iodide and/or thiosulfate, separation of unreacted Cr(VI) as its 1,5-diphenilcarbazide complex on a column filled with Amberlite XAD-16, elution of the complex by 10 mL of 0.05 mol L-1 H2SO4 in methanol and determination by flame atomic absorption spectrometry. Amount of the analytes were calculated from the amount of Cr(VI) reacted with the analytes. The optimum conditions for the determination of iodide and thiosulfate ions, including pH and volume of sample solution were examined. The effect of interfering species on the recovery of the iodide and thiosulfate ions was also investigated. The precision of the proposed method is good as it provides relative standard deviation value of 3.5% for thiosulfate and 4.5% for iodide during five replicate determinations of 10 µg mL-1 of thiosulfate and 15 µg mL-1 of iodide, respectively. The accuracy of the procedure was tested by analyzing spiked real samples and certified reference sample (BCR 150 Milk powder). The procedure described was successfully applied for the determination of iodide in table salt and milk and, thiosulfate in table salt. Iodide and thiosulfate ions have been determined in real samples with relative error below 15%.

Synthesis of nano B2O3/TiO2 composite material as a new solid phase extractor and its application to preconcentration and separation of cadmium.

A new solid phase extractor, nano-scale diboron trioxide/titanium dioxide composite material, was synthesized and used for separation and/or preconcentration of trace cadmium ion from various samples. The characterization of the synthesized material was performed by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffractometer methods (XRD). The specific surface area of the material was also determined and found as 3.4m(2)/g. Analytical parameters including pH of sample solution, sample volume, flow rate of sample solution, volume and concentration of eluent for the column solid phase extraction (SPE) procedure were examined. The effect of common matrix ions on the recovery of the cadmium has also been investigated and found that they did not interfere on cadmium preconcentration. Under the optimum experimental conditions, preconcentration factor and analytical detection limit were determined as 50 and 1.44 microg/L, respectively. The reusability (stabile up to 100 run) and adsorption capacity (49 mg/g) of the sorbent were excellent. The accuracy of the method was confirmed by analyzing certified reference materials (Tea leaves GBW-07605). The results demonstrated good agreement with the certified values (relative error <10%). The precision of the method was also satisfactory. The recovery of cadmium under the optimum conditions was found to be 96+/-3% at 95% confidence level. The method was applied for the determination of cadmium in tap water and tea leaves.

Optimization of selenium determination in chicken's meat and eggs by the hydride-generation atomic absorption spectrometry method.

Effect of selenium-enriched feed on the selenium content of chicken meat and eggs was investigated. Selenium was determined by hydride-generation atomic absorption spectrometry (HG-AAS). The effect of digestion procedures on the determination was also studied. Optimum values of the variables applied for the HG-AAS method, such as HCl and NaBH(4) concentration, and the flow rate of carrier gas were determined experimentally. Analytical parameters such as the selectivity, accuracy, precision, sensitivity, limit of detection and limit of quantification were also determined. The limit of detection and the limit of quantification were 0.78 microg/l and 2.35 microg/l, respectively. The effect of interfering elements that are possibly present in the samples analyzed on the recovery of selenium was also investigated. The measurements were validated using diverse types of certified reference materials (IRMM IMEP 19, LGC 7160 and GBW 08572) and by a method of yield measurement of calibration solution addition in mineralized samples. The accuracy and precision of the method are satisfactory and the relative standard deviation is less than 4%, and the relative error is less than 10% for a 500 microl sample containing 10 microg/l selenium. It was observed that the selenium content of chicken meat and eggs obtained from the chickens nourished with fortified feed was higher than those without fortified feed.

Penicillium digitatum immobilized on pumice stone as a new solid phase extractor for preconcentration and/or separation of trace metals in environmental samples.

This study presents a column solid phase extraction procedure based on column biosorption of Cu(II), Zn(II) and Pb(II) ions on Penicillium digitatum immobilized on pumice stone. The analytes were determined by flame atomic absorption spectrometry (FAAS). The optimum conditions such as: pH values, amount of solid phase, elution solution and flow rate of sample solution were evaluated for the quantitative recovery of the analytes. The effect of interfering ions on the recovery of the analytes has also been investigated. The recoveries of copper, zinc and lead under the optimum conditions were found to be 97+/-2, 98+/-2 and 98+/-2%, respectively, at 95% confidence level. For the analytes, 50-fold preconcentration was obtained. The analytical detection limits for Cu(II), Zn(II) and Pb(II) were 1.8, 1.3 and 5.8 ng mL(-1), respectively. The proposed procedure was applied for the determination of copper, zinc and lead in dam water, waste water, spring water, parsley and carrot. The accuracy of the procedure was checked by determining copper, zinc and lead in standard reference tea samples (GBW-07605).

Removal of cadmium(II) ion from aqueous system by dry biomass, immobilized live and heat-inactivated Oscillatoria sp. H1 isolated from freshwater (Mogan Lake).

Oscillatoria sp. H1 (Cyanobacteria, microalgae) isolated from Mogan Lake was used for the removal of cadmium ions from aqueous solutions as its dry biomass, alive and heat-inactivated immobilized form on Ca-alginate. Particularly, the effect of physicochemical parameters like pH, initial concentration and contact time were investigated. The sorption of Cd(II) ions on the sorbent used was examined for the cadmium concentrations within the range of 25-250 mg/L. The biosorption of Cd(II) increased as the initial concentration of Cd(II) ions increased in the medium up to 100 mg/L. Maximum biosorption capacities for plain alginate beads, dry biomass, immobilized live Oscillatoria sp. H1 and immobilized heat-inactivated Oscillatoria sp. H1 were 21.2, 30.1, 32.2 and 27.5 mg/g, respectively. Biosorption equilibrium was established in about 1 h for the biosorption processes. The biosorption was well described by Langmuir and Freundlich adsorption isotherms. Maximum adsorption was observed at pH 6.0. The alginate-algae beads could be regenerated using 50 mL of 0.1 mol/L HCl solution with about 85% recovery.

Method validation for the determination of lead in raw cow's milk by electrothermal atomic absorption spectrometry.

In this study, lead in raw cow's milk has been determined by validated electrothermal atomic absorption spectrometry (ETAAS) with Zeeman-effect background correction. Maximum pyrolysis and optimum atomization temperatures of lead were determined in the presence of modifiers. Pd + Mg(NO3)2 has been found a powerful modifier mixture for the determination of lead. The analytical parameters of the method such as limit of detection, limit of quantification and the effect of interfering ions have been investigated. The detection limit (3sigma) achieved by the method was calculated to be 0.62 ng/mL for Pb. Repeatability of the method evaluated as the relative standard deviation of 16-17 replicates using 5 ng/mL, under optimum experimental conditions were about 1.5% for synthetic sample solution and about 3% for real sample (N = 5). The described method has been validated by analyzing certified reference material (BCR-CRM 150) and by comparing the results with those obtained by inductively coupled plasma mass spectrometry (ICP-MS). The validated method was applied to raw cow's milk samples produced in 7 different regions of Turkey in 2003-2004. Raw cow's milk contained a mean (range) of 31.4 (2.5 - 313) microg kg(-1) lead with a relative error below 2%.

Optimization of a new resin, Amberlyst 36, as a solid-phase extractor and determination of copper(II) in drinking water and tea samples by flame atomic absorption spectrometry.

A new simple and reliable method has been developed to separate and preconcentrate trace copper ion in drinking water and tea samples for subsequent measurement by flame atomic absorption spectrometry (FAAS). The copper ions are adsorbed quantitatively during passage of aqueous solutions through Amberlyst 36 cation exchange resin. After the separation and preconcentration stage, the analyte was eluted with a potassium cyanide solution and determined by FAAS. Different factors including pH of sample solution, sample volume, amount of resin, flow rate of aqueous solution, volume and concentration of eluent, and matrix effects for preconcentration were examined. The analytical figures of merit for the determination of copper are as follows: analytical detection limit (3 sigma), 0.26 microg/L; precision (RSD), 3.1% for 100 microg/L; enrichment factor, 200 (using 1000 mL of sample solution and 5 mL of eluent); time of analysis, 3.5 h (for obtaining enrichment factor of 200); capacity of resin, 125 mg/g. The method was applied for copper determination by FAAS in tap water, commercial natural spring water, commercial treated drinking water, and commercial tea bag sample. The accuracy of the method is confirmed by analyzing tea leaves (GBW 07605). The results demonstrated good agreement with the certified values.

Determination of trace cadmium in waters by flame atomic absorption spectrophotometry after preconcentration with 1-nitroso-2-naphthol-3,6-disulfonic acid on Ambersorb 572.

A procedure for the determination of trace amount of cadmium after adsorption of its 1-nitroso-2-naphthol-3,6-disulfonic acid chelate on Ambersorb 572 has been proposed. This chelate is adsorbed on the adsorbent in the pH range 3-8 from large volumes of aqueous solution of water samples with a preconcentration factor of 200. After being sorbed, cadmium was eluted by 5 mL of 2.0 mol L(-1) nitric acid solution and determined directly by flame atomic absorption spectrophotometery (FAAS). The detection limit (3sigma) of cadmium was 0.32 microg L(-1). The precision of the proposed procedure, calculated as the relative standard deviation of recovery in sample solution (100 mL) containing 5 microg of cadmium was satisfactory (1.9%). The adsorption of cadmium onto adsorbent can formally be described by a Langmuir equation with a maximum adsorption capacity of 19.6 mg g(-1) and a binding constant of 6.5 x 10(-3) L mg(-1). Various parameters, such as the effect of pH and the interference of a number of metal ions on the determination of cadmium, have been studied in detail to optimize the conditions for the preconcentration and determination of cadmium in water samples. This procedure was applied to the determination of cadmium in tap and river water samples.

Application of silica gel 60 loaded with Aspergillus niger as a solid phase extractor for the separation/preconcentration of chromium(III), copper(II), zinc(II), and cadmium(II).

Sorption properties of silica gel 60 loaded with fungi cells characterized as Aspergillus niger were evaluated for trace enrichment of Cr(III), Cu(II), Zn(II), and Cd(II) from various water samples prior to the description of flame atomic absorption spectrometric analysis. The proposed SPE method is cheap, simple, highly sensitive, accurate, and selective for enrichment of analytes. The effect of experimental parameters, such as pH of sample solution, amount of solid phase, eluent type, and volume of sample solution on the recovery of the metal ions has been investigated. The effect of diverse ions was also investigated. The recoveries of Cr(III), Cu(II), Zn(II), and Cd(II) under the optimum experimental conditions were 98 +/- 2, 98 +/- 3, 99 +/- 2, 100 +/- 2%, respectively, at the 95% confidence level. The analytical detection limits were found to be 3.1, 1.6, 1.1, and 1.4 microg/L for Cr(III), Cu(II), Zn(II), and Cd(II), respectively. The proposed enrichment method was applied to the determination of analytes in Atatürk Dam, Egirdir Lake, and tap-water samples. The analytes were determined with a relative error lower than 8% in various water samples. The method has been validated by analyzing spiked water samples.