? Shin, S.R. (2006), Analysis of smoking and smoking cessation related nursing research in Korea and its future direction. Taehan Kanho Hakhoe Chi, 36 (2), 415-425.
Full Text: 2006\Tae Kan Hak Chi36, 415.pdf
Abstract: PURPOSE: The purpose of this study was to analyze the contents and trend of smoking and smoking cessation related nursing research in Korea and to suggest the directions for future research. METHOD: Eight nursing professional Journals published by the Korean Academic Nursing Society and by 7--adult, community, psychiatric, fundamental, obstetrics, pediatrics, administrative--nursing societies from beginning edition to October 2005 were selected. They were examined for the proportion of published research, participants, research designs, key words, measurement tools, and the intervention outcomes in the case of the experimental research. RESULT: Of the research analyzed, 87 studies were smoking and smoking cessation related research. The Journals, which had published the most number of smoking and smoking cessation research were J of Korean Academic Society, J of Korean Adult Nursing Society, J of Korean Community Nursing Society. The most popular research design was an descriptive design. The major concepts studied were related psychosocial variables. Among 87 studies, only 11 were experimental research. CONCLUSION: Research on smoking and smoking cessation in the nursing discipline are increasing. However more research to test the effectiveness of nursing intervention programs are needed.
Publisher Address: PO Box 211, 1000 AE Amsterdam, Netherlands
Chemistry, Analytical: Impact Factor
Brainina, Kh.Z. and Tchernyshova, A.B. (1974), Inverse voltammetry of antimony with triphenylmethane dyes. Talanta, 21 (4), 287-293.
Full Text: 1960-80\Talanta21, 287.pdf
Abstract: A method is suggested for the determination of traces of antimony by inverse voltammetry of the solid phases formed with triphenylmethane dyes (Crystal Violet, Methyl Violet and Malachite Green) as the precipitants. The authors have studied the effect of concentration, adsorption and oxidation of the triphenylmethane dyes, potential and time of pre-electrolysis, and concentration of antimony(III) and some other elements on the polarogram shape and stripping current. A method for determining antimony traces in chromic salts is described as an example.
López-Cueto, G., Casado-Riobó, J.A. and Lucena-Conde, F. (1974), Catalytic effect of copper on the hexacyanoferrate(III)-cyanide redox reaction. Talanta, 21 (6), 669-670.
Full Text: 1960-80\Talanta21, 669.pdf
Abstract: The oxidation of cyanide with hexacyanoferrate(III) is a thermodynamically possible but kinetically slow reaction, which is catalysed by copper(II). The catalysed reaction has a second-order dependence on hexacyanoferrate(III) concentration, and the pseudo second-order rate constant increases linearly with the copper concentration, at least in the range from 10-7 to 10-3M.
Robberecht, H. and Van Grieken, R. (1982), Selenium in environmental waters: Determination, speciation and concentration levels. Talanta, 29 (10), 823-844.
Full Text: 1982\Talanta29, 823.pdf
Abstract: This article reviews the different methods used for the determination of selenium species in all types of environmental waters. Basic difficulties are discussed and the efficiency of the methods is explained in view of the sub-µg/1. concentration levels. Special attention is paid to preconcentration steps. Published data on speciation and concentration levels in various water samples are critically reviewed.
? Myasoedova, G.V., Antokolskaya, I.I. and Savvin, S.B. (1985), New chelating sorbents for noble metals. Talanta, 32 (12), 1105-1112.
Full Text: 1985\Talanta32, 1105.pdf
Abstract: properties of the new chelate-forming “POLYORGS” sorbents for concentration of noble metals are discussed. POLYORGS are made from different polymeric matrices (polystyrene, copolymers of styrene with divinylbenzene, fibrous materials). They contain heterocyclic amine and amidoxime groups, and are selective for noble metals. Some methods of noble metal determination after preliminary concentration of POLYORGS sorbents are given.
Tsezos, M. and Mattar, S. (1986), A further insight into the mechanism of biosorption of metals, by examining chitin EPR spectra. Talanta, 33 (3), 225-232.
Full Text: 1986\Talanta33, 225.pdf
Abstract: Experimental chitin-uranium-copper EPR spectra have been simulated by computer. The simulation suggests that the chitin-copper-uranium EPR spectra are primarily due to a chitin-copper interaction, with insignificant contribution from other paramagnetic species. The simulation suggests two possible complex configurations, both involving one ligand nitrogen atom.
El-Shahawi, M.S. (1994), Retention and separation of some organic water pollutions with unloaded and tri-n-octylamine loaded polyester-based polyurethane foams. Talanta, 41 (9), 1481-1488.
Full Text: 1994\Talanta41, 1481.pdf
Abstract: The analytical utility of unloaded and polyester-based polyurethane loaded foams with tri-n-octylamine (TOA) in the removal of some phenols from water were carried out. In static mode, the TOA-loaded foams showed a good affinity of extraction towards the tested compounds as compared to the untreated foams. The various parameters affecting the retention efficiency of the tested compounds from aqueous media by the foam were examined via batch technique. The TOA-loaded foams were employed in column modes for the extraction and recovery of the tested phenols. The retention efficiency and the recovery of the tested compounds from the loaded foam column were up to 98.5%. Sorption of the compounds by the foam were brought by solvent extraction mechanism. The molecular weight and the pKa of the compounds play an important role in the extraction process. The height equivalent to a theoretical plate (HETP) of the TOA-foam column was found in the range 1.8–2.05 ± 0.1 mm at flow-rates up to 10 cm3/min. Separation of some of the tested phenols was also carried out by the TOA-foam columns. The membrane properties of the polyester foam sorbents give unique advantages over conventional granular sorbents in rapid, versatile and effective separations and preconcentrations of the tested compounds.
Notes: highly cited
? Fang, Z.L., Xu, S.K., Dong, L.P. and Li, W.Q. (1994), Determination of cadmium in biological-materials by flame atomic-absorption spectrometry with flow-injection online sorption preconcentration. Talanta, 41 (12), 2165-2172.
Full Text: 1994\Talanta41, 2165.pdf
Abstract: A new on-line preconcentration flame atomic absorption spectrometry (FAAS) system for trace element determination was developed based on sorption of soluble metal complexes on the walls of a PTFE knotted reactor using flow injection techniques. The system was applied to the determination of cadmium in biological materials. Cadmium complexed with sodium diethyldithiocarbamate was sorbed on the inner walls of the reactor and eluted on-line by isobutyl methyl ketone. The retention efficiency was 81% at a sampling loading rate of 5.2 ml/min. The enhancement factor was 66 and the concentration efficiency was 61/min with a 50 sec preconcentration period, consuming 4.2 ml sample. A detection limit of 0.1 mu g/l. Cd (3 sigma) was obtained with a sampling frequency of 55/hr. The precisions were 1.2% RSD for 20 mu g/l. Cd (N = 11). Thiourea and ascorbic acid/phenanthroline were used to overcome interferences from copper and iron, respectively. The analytical results obtained for powdered rice and human hair standard reference materials were in good agreement with the certified values.
? Katragadda, S., Gesser, H.D. and Chow, A. (1995), Evaluation of a -diketone-imbedded polyurethane foam. Talanta, 42 (5), 725-731.
Full Text: 1995\Talanta42, 725.pdf
Abstract: A beta-diketone-imbedded polyurethane foam was made for the sorption of uranium from aqueous solutions. The incorporation of the beta-diketone functional group into the polyurethane foam was simple, and relatively inexpensive. The beta-diketone foam was ground to facilitate the evaluation of its ability to extract uranium from aqueous solutions with a wide range of temperature and pH values. The beta-diketone material showed superior extractability of uranium from solutions with pH 7±3. In general, the beta-diketone material showed greater extractability of uranium at all temperatures and pH values tested when compared to a blank polyurethane foam without the beta-diketone functional group.
Sarkar, A.R., Datta, P.K. and Sarkar, M. (1996), Sorption recovery of metal ions using silica gel modified with salicylaldoxime. Talanta, 43 (11), 1857-1862.
Full Text: 1996\Talanta43, 1857.pdf
Abstract: Trace metals in water were preconcentrated with silica gel modified with salicylaldoxime and determined by AAS. Optimum conditions for the maximum recovery of metal ions, viz. Cu(II), Ni(II), Co(II), Zn(II) and Fe(III), for both batch and column methods were developed. The efficiency of the adsorbent with respect to different experimental conditions was established. (C) 1996 Elsevier Science B.V. All rights reserved.
Ahuja, M., Rai, A.K. and Mathur, N. (1996), Adsorption behaviour of metal ions on hydroximate resins. Talanta, 43 (11), 1955-1963.
Full Text: 1996\Talanta43, 1955.pdf
Abstract: Some new chelating ion-exchange resins containing a hydroxamic acid moiety attached to a divinylbenzene styrene (DVBS) copolymer, i.e., glycine hydroximate in DVBS (GH-DVBS), anthranilic acid hydroximate in DVBS (AAH-DVBS), malonic acid dihydroximate in DVBS (MAH-DVBS) and iminodiacetic acid dihydroximate in DVBS (IDAAH-DVBS), have been synthesized and their various physicochemical characteristics studied. The degree of retention of metal ions by the resins at equilibrium has been determined in terms of the molar distribution coefficient (Kd). In general, the resins having a dihydroximate moiety are found to be more efficient compared to monohydroximate resins. However, it is of interest to note that the monohydroximate derivative of amino acid (GH-DVBS) showed better metal retention capability than the dihydroximate of carboxylic acid (MAH-DVBS). The selectivity of the resins for transition and highly charged metal ions is quite high compared to that for alkaline earth metals. All the synthesized resins can be utilized for the separation of a mixture of metal ions because the differences in the distribution coefficient values are large enough to permit good separations on columns. However, the GH-DVBS resin was tried for the separation of copper-cobalt and copper-nickel mixtures at pH 5.5 using the column mode of operation.
? Katragadda, S., Gesser, H.D. and Chow, A. (1997), Extraction of uranium from aqueous solution by phosphonic acid imbedded polymethane foam. Talanta, 44 (10), 1865-1871.
Full Text: 1997\Talanta44, 1865.pdf
Abstract: Phenylphosphonic acid was imbedded into the matrix of the polyurethane foam during the fabrication process of the polymer. The extraction of uranium by phosphonic acid-imbedded polyurethane foam and blank polyurethane (i.e., foam without phosphonic acid functional groups) was investigated. Phosphonic acid-imbedded foam showed superior extractability of uranium from solutions with pH = 7.0 +/- 1.5 over a wide range of temperature. (C) 1997 Elsevier Science B.V.
Denizli, A., Kesenci, K., Arıca, M.Y., Salih, B., Hasırcı, V. and Pişkin, E. (1998), Novel dye-attached macroporous films for cadmium, zinc and lead sorption: Alkali Blue 6B-attached macroporous poly(2-hydroxyethyl methacrylate). Talanta, 46 (4), 551-558.
Full Text: 1998\Talanta46, 551.pdf
Abstract: Alkali Blue 6B-attached poly(2-hydroxyethyl methacrylate) (poly(HEMA)) microporous films were investigated as chelate forming sorbents for heavy metal removal. Poly(HEMA) microporous films were prepared by UV-initiated photo-polymerization of HEMA in the presence of an initiator (azobisisobutyronitrile (AIBN)). Alkali Blue 6B was attached covalently. These films with a swelling ratio of 58%, and carrying 14.8 mmol Alkali Blue 6B m−2 which were then used in the removal of Cd(II), Zn(II) and Pb(II) from aqueous media. Adsorption rates were very high, equilibrium was achieved in about 30 min. The maximum adsorption of heavy metal ions onto the Alkali Blue 6B-attached films were 41.4 mmol m−2 for Cd(II), 52.4 mmol m−2 for Zn(II), and 64.5 mmol m−2 for Pb(II). When the heavy metal ions competed during the adsorption from a mixture the adsorption values for Cd(II), Zn(II) and Pb(II) were quite close. Heavy metal ions were desorbed by using 0.1 M HNO3. A significant amount of the adsorbed heavy metal ions (up to 95%) could be desorbed in 30 min. Repeated adsorption/desorption cycles showed the feasibility of these novel dye-attached microporous films for heavy metal removal. (C) 1998 Elsevier Science B.V. All rights reserved.
Keywords: Alkali Blue 6B, Poly(HEMA) Films, Heavy Metal Removal, Cadmium(II), Zinc(II), Lead(II)
Salih, B., Denizli, A., Kavakli, C., Say, R. and Pişkin, E. (1998), Adsorption of heavy metal ions onto dithizone-anchored poly (EGDMA-HEMA) microbeads. Talanta, 46 (5), 1205-1213.
Full Text: 1998\Talanta46, 1205.pdf
Abstract: The dithizone-anchored poly (EGDMA-HEMA) microbeads were prepared for the removal of heavy metal ions (i.e., cadmium, mercury, chromium and lead) from aqueous media containing different amounts of these ions (25-500 ppm) and at different pH values (2.0-8.0). The maximum adsorptions of heavy metal ions onto the dithizone-anchored microbeads from their solutions was 18.3, Cd(II); 43.1, Hg(II); 62.2, Cr(III) and 155.2 mgg-1 for Pb(II). Competition between heavy metal ions (in the case of adsorption from mixture) yielded adsorption capacities of 9.7, Cd(II); 28.7, Hg(II); 17.6, Cr(III) and 38.3 mgg-1 for Pb(II). The same affinity order was observed under non-competitive and competitive adsorption, i.e., Cr(III)> Pb(II)> Hg(II) > Cd(II). The adsorption of heavy metal ions increased with increasing pH and reached a plateaue value at around pH 5.0. Heavy metal ion adsorption from artificial wastewater was also studied. The adsorption capacities are 4.3, Cd(II); 13.2, Hg(II); 7.2, Cr(III) and 16.4 mgg-1 for Pb(II). Desorption of heavy metal ions was achieved using 0.1 M HNO3. The dithizone-anchored microbeads are suitable for repeated use (for more than five cycles) without noticeable loss of capacity.
Keywords: Attached Poly (Egdma-Hema) Microspheres, Biosorption Characteristics, Removal, Preconcentration, Ligands, Dithizone, Poly (Egdma-Hema) Microbeads, Heavy Metal Removal, Cadmium, Mercury, Chromium and Lead
Brandariz, I., Vilariño, T., Alonso, P., Herrero, R., Fiol, S. and Sastre de Vicente, M.E. (1998), Effect of ionic strength on the formal potential of the glass electrode in various saline media. Talanta, 46 (6), 1469-1477.
Full Text: 1998\Talanta46, 1469.pdf
Abstract: We examined the variation with ionic strength (I, adjusted with KCl, KNO3, KBr, NaCl or NaClO4) of the formal potential (Econst) for glass electrodes exhibiting a Nernstian response (i.e. Ecell=Econst-s log [H+]). For this purpose, we investigated the different factors included in the formal potential, so we obtained reported values for the liquid junction potential as a function of ionic strength and determined the logarithm of the activity coefficient for the proton in various saline media, using Pitzer equations.
Lubal, P., Široky, D., Fetsch, D. and Havel, J. (1998), The acidobasic and complexation properties of humic acids: Study of complexation of Czech humic acids with metal ions. Talanta, 47 (2), 401-412.
Full Text: 1998\Talanta47, 401.pdf
Abstract: The acid-base and complexation properties of humic acids (HAs) extracted from bohemian brown coals were studied. The acid-base behavior corresponds with the model of KA as a mixture of mono- and diprotic acids. This model was also verified on commercial HA substances (Aldrich and Fluka). HA binds strongly with heavy metal ions and the highest stability constant of HA-metal ion complexes was observed for copper(IT). Stability constant values were found to decrease in the order: Cu2+ > Ba2+ > Pb2+ > Cd2+ > Ca2+. Both acidobasic models for HA alone and those for HA-metal ion interactions were proposed and the computational methodology for polyelectrolyte equilibria studies demonstrated. (C) 1998 Elsevier Science B.V. All rights reserved.
Keywords: Complexation, Humic Acids, Metal Ions, Modeling, Carboxyl-Group Structures, Base Properties, Suwannee River, Fulvic-Acid, Electrophoresis, Substances, Georgia
Nifant’eva, T.I., Shkinev, V.M., Spivakov, B.Y. and Burba, P. (1999), Membrane filtration studies of aquatic humic substances and their metal species: A concise overview. Part 2. Evaluation of conditional stability constants by using ultrafiltration. Talanta, 48 (2), 257-267.
Full Text: 1999\Talanta48, 257.pdf
Abstract: The assessment of conditional stability constants of aquatic humic substance (HS) metal complexes is overviewed with special emphasis on the application of ultrafiltration methods. Fundamentals and limitations of stability functions in the case of macromolecular and polydisperse metal-HS species in aquatic environments are critically discussed. The review summarizes the advantages and application of ultrafiltration for metal-HS complexation studies, discusses the comparibility and reliability of stability constants. The potential of ultrafiltration procedures for characterizing the lability of metal-HS species is also stressed. (C) 1999 Elsevier Science B.V. All rights reserved.
Saeed, M.M., Hasany, S.M. and Ahmed, M. (1999), Adsorption and thermodynamic characteristics of Hg(II)-SCN complex onto polyurethane foam. Talanta, 50 (3), 625-634.
Full Text: 1999\Talanta50, 625.pdf
Abstract: The sorption of Hg(II) in the presence of sodium thiocyanate solution onto polyurethane (PUR) foam, an excellent sorbent, has been investigated in detail. Maximum sorption of Hg(II) is achieved from 0.1 M hydrochloric acid solution containing 7.510-2 M sodium thiocyanate in 5 min. The sorption data followed both Freundlich and Langmuir adsorption isotherms. The Freundlich constants 1/n and sorption capacity, C-m, are evaluated to be 0.440.02 and (3.860.89)10-5 mol g-1. The saturation capacity and adsorption constant derived from Langmuir isotherm are (6.880.28)10-5 mol g-1 and (5.60.37)104 dm3 mol-1) respectively. The mean free energy (E) of Hg(II)-SCN sorption onto PUR foam computed from D-R isotherm is 12.40.3 kJ mol-1 indicating ion-exchange type mechanism of chemisorption. The variation of sorption with temperature yields thermodynamic parameters of Delta H = -30.71.2 kJ mol-1, Delta S = -70.14.1 J mol-1 K-1 and Delta G = -9.860.77 kJ mol-1 at 298 It. The negative value of enthalpy and free energy reflects the exothermic and spontaneous nature of sorption. On the basis of the sorption data, sorption mechanism has been proposed. (C) 1999 Elsevier Science B.V. All rights reserved.
Alam, T., Tarannum, H., Kumar, M.N.V.R. and Kamaluddin. (2000), Adsorption and oxidation of aromatic amines by metal hexacyanoferrates(II). Talanta, 51 (6), 1097-1105.
Full Text: 2000\Talanta51, 1097.pdf
Abstract: Interaction of aniline, p-toluidine and p-chloroaniline with nickel, cadmium and manganese hexacyanoferrates(II) has been studied. Nickel and cadmium hexacyanoferrates(II) showed maximum adsorption at neutral pH, whereas, manganese hexacyanoferrate(II) reacts with aniline, p-toluidine and p-chloroaniline forming the colored oligomers on its surface. The adsorption data obtained at neutral pH is fitted in Langmuir adsorption isotherm. The adsorption behavior of the studied aromatic amines followed the order: p-toluidine > aniline > p-chloroaniline, which is related to the basicities of the amines. Results of the present study suggest the importance of metal hexacyanoferrates(II) and metal ions in stabilization of aromatic amines during the processes of prebiotic condensation reactions. (C) 2000 Elsevier Science B.V. All rights reserved.
Keywords: Aromatic Amines, Metal Hexacyanoferrates(II), Adsorption, Montmorillonite, Nucleotides, Adenine
? Ohta, K., Tanahasi, H., Suzuki, T. and Kaneco, S. (2001), Preconcentration of trace copper with yeast for river water analysis. Talanta, 53 (4), 715-720.
Full Text: 2001\Talanta53, 715.pdf
Abstract: A new preconcentration method with yeast is presented. The method was evaluated for the determination of trace copper in river water by graphite furnace atomic absorption spectrometry (GFAAS). A suitable cultivation bed for preconcentration of copper was 3.5 mg ml-1 2-ammonium hydrogen phosphate. The optimal cultivation time and temperature were 2 h and 40 degreesC. Under optimal conditions, copper in aqueous sample was concentrated about seven-fold by yeast. The detection limit was 85 pg ml-1 (3S/N) for copper in river waters. The yeast preconcentration method was applied to the determination of copper in river waters. The recovery of spiked copper was in the range of 93-100%. By the preconcentration, it was found that ultra trace copper in river waters could be determined without interferences of matrix elements, after only the cultivation and no chemical treatment. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.
Hasany, S.M., Saeed, M.M. and Ahmed, M. (2001), Sorption of traces of silver ions onto polyurethane foam from acidic solution. Talanta, 54 (1), 89-98.
Full Text: 2001\Talanta54, 89.pdf
Abstract: The sorption of traces of silver ions onto polyurethane foam (PUF) has been investigated in detail. Maximum sorption of silver (Kd = 6109 cm3g-1, %sorption > 97.5%) has been achieved from 1 M nitric acid solution after equilibrating silver ions with similar to 29 mg PUF for 20 min. The kinetics and thermodynamics of the sorption of silver ions onto PUF have also been studied. The sorption of silver ions onto PUF follows a first-order rate equation, which results as 0.177 min-1. The variation of sorption with temperature yields the values of DeltaH =-56.1±3.2 kJ mol-1 DeltaS =-159.7±10.5 J mol-1 K-1 and G =-8.68±0.09 kJ mol-1 at 298 K with a correlation factor = 0.9919. The sorption data were subjected to different sorption isotherms. The sorption follows Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms. The values of Langmuir isotherms Q = 65.3±1.5 µmol g-1 and b = (4.79±1.16)×104 dm3mol-1 have been evaluated for Langmuir sorption constants, whereas the Freundlich sorption isotherm gives the value lin = 0.12±0.02 and A = 0.15±0.03 mmol g-1. The D-R parameters computed were beta =-0.000817±0.000206 mol2 kJ-2, Xm = 76.8±8.7 µmol g-1 and E = 24.7±3.2 kJ mol-1. The influence of common ions on the sorption was also examined. It is observed that Hg(II), thioura, Al(III), thiocyanate and thiosulphate reduce the sorption, whereas Cu(II), citrate and acetate ions enhance the sorption significantly. It can be concluded that PUF may be used to remove traces of silver ions from its very dilute solutions or for its preconcentration from aqueous acidic solutions. (C) 2001 Elsevier Science B.V. All rights reserved.
? Mandal, B.K. and Suzuki, K.T. (2002), Arsenic round the world: A review. Talanta, 58 (1), 201-235.
Full Text: 2002\Talanta58, 201.pdf
Abstract: This review deals with environmental origin, occurrence, episodes, and impact on human health of arsenic. Arsenic, a metalloid occurs naturally, being the 20th most abundant element in the earth’s crust, and is a component of more than 245 minerals. These are mostly ores containing sulfide, along with copper, nickel, lead, cobalt, or other metals. Arsenic and its compounds are mobile in the environment. Weathering of rocks converts arsenic sulfides to arsenic trioxide, which enters the arsenic cycle as dust or by dissolution in rain, rivers, or groundwater. So, groundwater contamination by arsenic is a serious threat to mankind all over the world. It can also enter food chain causing wide spread distribution throughout the plant and animal kingdoms. However, fish, fruits, and vegetables primarily contain organic arsenic, less than 10% of the arsenic in these foods exists in the inorganic form, although the arsenic content of many foods (i.e. milk and dairy products, beef and pork, poultry, and cereals) is mainly inorganic, typically 65-75%. A few recent studies report 85-95% inorganic arsenic in rice and vegetables, which suggest more studies for standardisation. Humans are exposed to this toxic arsenic primarily from air, food, and water. Thousands and thousands of people are suffering from the toxic effects of arsenicals in many countries all over the world due to natural groundwater contamination as well as industrial effluent and drainage problems. Arsenic, being a normal component of human body is transported by the blood to different organs in the body, mainly in the form of MMA after ingestion. It causes a variety of adverse health effects to humans after acute and chronic exposures such as dermal changes (pigmentation, hyperkeratoses, and ulceration), respiratory, pulmonary, cardiovascular, gastrointestinal, hematological, hepatic, renal, neurological, developmental, reproductive, immunologic, genotoxic, mutagenetic, and carcinogenic effects. Key research studies are needed for improving arsenic risk assessment at low exposure levels urgently among all the arsenic research groups. (C) 2002 Elsevier Science B.V. All rights reserved.
Abate, G., Lichtig, J. and Masini, J.C. (2002), Construction and evaluation of a flow-through cell adapted to a commercial static mercury drop electrode (SMDE) to study the adsorption of Cd(II) and Pb(II) on vermiculite. Talanta, 58 (3), 433-443.
Full Text: 2002\Talanta58, 433.pdf
Abstract: This paper describes the construction and application of a robust flow-through cell for use with the capillary of a commercial static mercury drop electrode. Linearity of peak current was observed up to 0.50 mumol l-1 for Cd(II) or Pb(II) in anodic stripping voltammetry experiments performed under continuous flow during the deposition step, using 120 s of deposition time and flow rate of 4.0 ml min-1. Under these conditions the limits of detection for Cd(II) and Pb(II) were 13 and 17 nmol l-1, respectively. An analytical throughput of 20 analyses per h was possible using 10 s for cleaning the cell between two samples and including the time needed for the potential scan, which was performed with the flow stopped, using the differential pulse mode for current sampling. The linear dynamic range can be extended up to 5 mumol l-1 for both cations if the deposition time is decreased to 30 s, a condition in which the sampling throughput is 35 analyses per h. The proposed manifold was used to study the adsorption rates of Cd(II) and Pb(II) onto vermiculite at different pHs, allowing one to perform high sensitivity measurements at high sampling frequency, using low cost instrumentation. (C) 2002 Elsevier Science B.V. All rights reserved.
Keywords: Continuous Flow Analysis, Voltammetry, Heavy Metals, Adsorption, Clays, Anodic-Stripping Voltammetry, Injection-Analysis, Heavy-Metals, Clay-Minerals, Trace-Metals, System, Cadmium, Lead
Ensafi, A.A., Khayamian, T. and Atabati, M. (2003), Differential pulse cathodic stripping adsorption voltammetric determination of trace amounts of lead using factorial design for optimization. Talanta, 59 (4), 727-733.
Full Text: 2003\Talanta59, 727.pdf
Abstract: A sensitive cathodic stripping voltammetric method is developed for determination of lead(II), with adsorptive collection of complexes with Pyrogallol red (PGR) on to a hanging mercury drop electrode. After accumulation of the complex at -0.80 V vs. Ag/AgCl reference electrode, the potential is scanned in a negative direction from -0.20 to -0.50 V with differential pulse method. Then the reduction peak current for the lead(II)-PGR complex is measured at 0.39 V. The influence of reagent and instrumental variables was completely studied by factorial design analysis. The optimum analytical conditions for the determination of lead(II) were established. Under optimum conditions, lead(II) determined in the range of 0.1-30.0 ng ml-1 with a limit of detection of 0.06 ng ml-1. The method is successfully applied to determination of lead(II) in water sample. (C) 2002 Elsevier Science B.V. All rights reserved.
? Mapolelo, M. and Torto, N. (2004), Trace enrichment of metal ions in aquatic environments by Saccharomyces cerevisiae. Talanta, 64 (1), 39-47.
Full Text: 2004\Talanta64, 39.pdf
Abstract: Sorption properties of baker’s yeast cells, characterised as Saccharomyces cervisiae were evaluated for trace enrichment of metal ions: Cd2+, Cr3+, Cr6+, Cu2+, Pb2+ and Zn2+ from aqueous environments. Metal concentration was determined by flame atomic absorption spectrometry (FAAS). Parameters affecting metal uptake such as solution pH, incubation time, amount of yeast biomass and effect of glucose concentration (energy source) were optimised. Further studies were carried out to evaluate the effects on metal uptake after treating yeast with glucose as well as with an organic solvent. The results showed that trace enrichment of the metals under study with yeast, depends upon the amount of yeast biomass, pH and incubation time. Treatment of yeast cells with 10-20 mM glucose concentration enhanced metal uptake with exception to Cr6+, whose metal enrichment capacity decreased at glucose concentration of 60 mM. Of the investigated organic solvents THF and DMSO showed the highest and lowest capacity, respectively, to enhance metal uptake by yeast cells. Trace enrichment of metal ions from stream water, dam water, treated wastewater from a sewage plant and wastewater from an electroplating plant achieved enrichment factors (EF) varying from 1 to 98, without pre-treatment of the sample. pH adjustment further enhanced the EF for all samples. The results from these studies demonstrate that yeast is a viable trace metal enrichment media that can be used freely suspended in solution to achieve very high EF in aquatic environments. (C) 2004 Published by Elsevier B.V.
? Mapolelo, M., Torto, N. and Prior, B. (2005), Evaluation of yeast strains as possible agents for trace enrichment of metal ions in aquatic environments. Talanta, 65 (4), 930-937.
Full Text: 2005\Talanta65, 930.pdf
Abstract: Sorption properties of six yeast strains were evaluated for trace enrichment of metal ions; Cd2+, Cr3+, Cr6+, Cu2+, Pb2+, and Zn2+, from aqueous environments. Metal concentration was determined by flame atomic absorption spectrometry (FAAS). The results showed that trace enrichment of the metals under study with yeast, was dependent on the pH and available metal ions. Enrichment time of 30 min gave an optimum metal uptake. The presence of Na+, K+, and Ca2+ suppressed the uptake of Pb by less than 5%, but suppressed the uptake of Zn by between 15 and 25%. Mg2+ Cu+, Cu2+, Cr3+, Cr6+, Cd2+, and Zn2+ suppressed the uptake of Pb by between 25 and 35%, and that of Zn by between 15 and 25%. For both Pb and Zn, Cd had the highest suppression of 35 and 30%, respectively for baker’s yeast (Saccharomyces cerevisiae). Baker’s yeast achieved enrichment factors (EF) of 23, 4, 100, and I for dam water, stream water, treated wastewater, and industrial effluent samples for Cu, Pb, Zn, and Cr, respectively. The recoveries of optimised Cd and Cr samples spiked with 2 mug ml-1 of the metal could reach up to 90%, but never exceeded 66% for 10 mug ml-1 samples. For Cu and Pb, the recoveries generally increased independent of concentration, however they were not as high as those for Zn, which exceeded 90% for all the samples spiked with 10 mug ml-1 of the metal. S. cerevisiae PR 61/3 had the highest EF for Cr as compared to the other yeast strains. S. cerevisiae PRI 60/78 was the only yeast strain which was able to enrich Cd in all the samples. Baker’s yeast had the highest EFs for Cu and Zn as compared to the other yeast strains without pH adjustment of the water samples. Candida tropicalis attained the highest EFs for Pb as compared to the other yeast strains. The results indicate that all the yeast strains used had a high affinity for Zn based on the EF values achieved. The results from these studies demonstrate that yeast is a viable trace metal enrichment agent that can be used freely suspended in solution to enrich metal ions at relatively low concentrations. This has ramifications on the traditional methods of sampling, sample collection, and transportation from remote sampling sites. (C) 2004 Elsevier B.V. All rights reserved.
? Malik, U.R., Hasany, S.M. and Subhani, M.S. (2005), Sorptive potential of sunflower stem for Cr(III) ions from aqueous solutions and its kinetic and thermodynamic profile. Talanta, 66 (1), 166-173.
Full Text: 2005\Talanta66, 166.pdf
Abstract: The sorptive potential of sunflower stem (180-300 m) for Cr(III) ions has been investigated in detail. The maximum sorption (>= 85%) of Cr(III) ions (70.2 M) has been accomplished using 30 mg of high density sunflower stem in 10min from 0.001M nitric and 0.0001 M hydrochloric acid solutions. The accumulation of Cr(III) ions on the sorbent follows Dubinin-Radushkevich (D-R), Freundlich and Langmuir isotherms. The isotherm yields D-R saturation capacity X-m = 1.60±0.23 mmol g-1, beta = -0.00654±0.00017 kj2 mol-2, mean free energy E=8.74±0.12 kJ mol-1, Freundlich sorption capacity K-F=0.24±0.11 mol g-1, 1/n=0.90±0.04 and of Langmuir constant K-L=6800±600 dm3 mol-1 and C-m= 120±18 molg-1. The variation of sorption with temperature (283-323K) gives H=-23.3±0.8 kJmol-1, S=-64.0±2.7 Jmol-1 K-1 and G(298k)=-4.04±0.09 kJ mol-1. The negative enthalpy and free energy envisage exothermic and spontaneous nature of sorption, respectively. Bisulphate, Fe(III), molybdate, citrate, Fe(II), Y(III) suppress the sorption significantly. The selectivity studies indicate that Cr(III), Eu(III) and Tb(III) ions can be separated from Tc(VII) and I(I). Sunflower stem can be used for the preconcentration and removal of Cr(III) ions from aqueous medium. This cheaper and novel sorbent has potential applications in analytical and environmental chemistry, in water decontamination, industrial waste treatment and in pollution abatement. A possible mechanism of biosorption of Cr(III) ions onto the sunflower stem has been proposed. (c) 2004 Elsevier B.V. All rights reserved.
? Parsons, J.G., Peralta-Videa, J.R., Tiemann, K.J., Saupe, G.B. and Gardea-Torresdey, J.L. (2005), Use of chemical modification and spectroscopic techniques to determine the binding and coordination of gadolinium(III) and neodymium(III) ions by alfalfa biomass. Talanta, 67 (1), 34-45.
Full Text: 2005\Talanta67, 34.pdf
Abstract: Metal pollution in the aqueous environment has become an important issue in the past few decades leading to extensive research in the area of pollution remediation. Most of the recent research in this area has been in bioremediation including phytofiltration and phytoextraction. Although there has been a lot of research done in the field of metal interactions with plants, the actual mechanism(s) and ligands involved are not well understood. Through a series of batch experiments, including pH profiles, time dependency studies, and capacity experiments, we have investigated the binding of Gd(III) and Nd(III) to alfalfa biomass. Batch pH studies showed that the optimum binding was at pH 5.0 for both elements. The time dependency experiments showed that the binding occurs within the first 5 min of contact and remains constant for up to 60 min. In addition, chemical modifications to the alfalfa biomass were performed to indirectly determine the ligands on the biomass responsible for metal binding. For Gd(III) binding, it was shown that the carboxyl groups on the biomass play the most important role in metal ion binding. However, for Nd(III), not only was it found that the carboxyl groups play an important role in the binding, but in addition, the amino groups on the biomass also play an important role in the binding of the metal ions. Further studies using X-ray absorption spectroscopy (XAS) showed that the Gd(III) and Nd(III) ions were bound to the alfalfa biomass through oxygen (or nitrogen ligands), which were coordinated to carbon atoms. The lanthanide complexes within the biomass included some coordinated water molecules. (C) 2005 Elsevier B.V. All rights reserved.
Keywords: Alfalfa, XAS, lanthanides, ICP-OES, X-Ray-Absorption, Medicago-Sativa Alfalfa, Near-Edge Structure, Saccharomyces-Cerevisiae, Au(III) Binding, Metal-Binding, Brown Seaweed, Heavy-Metals, Biosorption, XAS
? Sun, C.M., Qu, R.J., Ji, C.N., Wang, C.H., Sun, Y.Z., Yue, Z.W. and Cheng, G.X. (2006), Preparation and adsorption properties of crosslinked polystyrene-supported low-generation diethanolamine-typed dendrimer for metal ions. Talanta, 70 (1), 14-19.
Full Text: 2006\Talanta70, 14.pdf
Abstract: Two novel chelating resins, polystyrene supported G1.0 diethanolamine-typed dendrimer (PS-DEA) and G2.0 diethanolamine-typed dendrimer (PS-(DEA)2), were prepared by anchoring low-generations diethanolamine-typed dendrimer into crosslinked polystyrene in this paper. Fourier transform-infrared spectra (FTIR), scanning electron microscopy (SEM) and elemental analysis were employed to character their structures. The results of adsorption for metal ions showed that the resins had good adsorption capacities for Cu2+, Ag+ and Hg2+, especially PS-DEA for Cu2+. The adsorption kinetics and adsorption isotherms of PS-DEA for Cu2+ and PS-(DEA)2 for Hg2+ were studied. The results showed that the adsorption kinetics of the two resins can be modeled by pseudo second-order rate equation wonderfully and Langmuir and Freundlich equations could well interpret the adsorption of PS-(DEA)2 for Hg2+ and PS-DEA for Cu2+, respectively. The adsorption mechanism of the resins for Cu2+ was confirmed by X-ray photoelectron spectroscopy (XPS).
Keywords: Adsorption, Adsorption Kinetics, Isotherms, Kinetics, Mercury, Metal Ions, Pamam Dendrimer, Polymer-Supported Low-Generation Dendrimer, Preparation, Pseudo-Second-Order, Removal, Second-Order, SEM, Spectroscopy
? Liu, X.J., Qi, C., Bing, T., Cheng, X.H. and Shangguan, D. (2009), Specific mercury(II) adsorption by thymine-based sorbent. Talanta, 78 (1), 253-258.
Full Text: 2009\Talanta78, 253.pdf
Abstract: A new kind of polymer sorbent based on the specific interaction of Hg(II) with nucleic acid base, thymine, is described for the selective adsorption of Hg(II) from aqueous solution. Two types of sorbents immobilized with thymine were prepared by one-step swelling and polymerization and graft polymerization, respectively. The maximum static adsorption capacity of the new polymer sorbents for Hg(II) is proportional to the density of thymine on their surface, up to 200 mg/g. Moreover, the new kind polymer sorbent shows excellent selectivity for Hg(II) over other interfering ions, such as Cu(II), Cd(II), Zn(II), Co(II), Ca(II) and Mg(II), exhibits very fast kinetics for Hg(II) adsorption from aqueous solution, and can be easily regenerated by 1.0 M HCl. It also has been successfully used for the selective adsorption of spiked Hg(II) from real tap water samples. This new thymine polymer sorbent holds a great promise in laboratory and industrial applications such as separation, on-line enrichment, solid-phase extraction, and removal of Hg(II) from pharmaceutical, food and environmental samples. (c) 2008 Elsevier B.V. All rights reserved.
? Kim, M.L. and Tudino, M.B. (2009), Non-chromatographic determination of ultratraces of V(V) and V(IV) based on a double column solid phase extraction flow injection system coupled to electrothermal atomic absorption spectrometry. Talanta, 79 (3), 940-946.
Full Text: 2009\Talanta79, 940.pdf
Abstract: In this work, a non-chromatographic procedure for the on-line determination of ultratraces of V(V) and V(IV) is presented. The method involves a solid phase extraction-flow injection system coupled to electrothermal atomic absorption spectrometry (SPE-FI-ErAAS). The system holds two microcolumns (MC) set in parallel and filled with lab-made mesoporous silica functionalized with 3-aminopropyltriethoxy silane (APS) and mesoporous silica MCM-41, respectively. The pre-concentration of V(V) is performed by sorption onto the first MIC (C1) filled with APS at pH 3, whilst that of V(IV) is performed by sorption onto the second column (C2) filled with mesoporous silica MCM-41 at pH 5. Aqueous samples containing both analytes are loaded and, after pre-concentration (pre-concentration factor PCF = 10, sorption flow rate = 1 mL min-1, sorption time = 10 min), they are eluted in separate vessels with hydroxylammonium chloride(HC)0.1 mol L-1 in HCl 0.5 mol L-1 (elution volume = 1 mL elution flow rate = 0.5 mL min-1). Afterwards, both analytes are determined through ETAAS with graphite furnace. Under optimized conditions, the main analytical figures of merit for V(V) and V(IV) are, respectively: detection limits (3s): 0.5 and 0.6 g L-1, linear range: 2-100 g L-1 (both analytes), sensitivity: 0.015 and 0.013 g-1 L and sample throughput: 6 h-1 (both analytes). Recoveries of both species were assayed in different water samples. Validation was performed through certified reference materials for ultratraces of total vanadium in river water. (C) 2009 Elsevier B.V. All rights reserved.
? Ling, P.P., Liu, F.Q., Li, L.J., Jing, X.S., Yin, B.R., Chen, K.B. and Li, A.M. (2010), Adsorption of divalent heavy metal ions onto IDA-chelating resins: Simulation of physicochemical structures and elucidation of interaction mechanisms. Talanta, 81 (1-2), 424-432.
Full Text: 2010\Talanta81, 424.pdf
Abstract: The adsorption performances, under static as well as dynamic conditions, for such metal ions as Cu(II), Pb(II) and Cd(II) toward chelating resins (IRC748 and NDC702) similarly containing iminodiacetic acid group but diverse pore structures, are systematically performed and deeply exploited. The physicochemical characteristics of both IDA-chelating resins are thoroughly explored by EA, FT-IR, SEM-EDX and PSD. Langmuir isotherm and pseudo-second-order equation could satisfactorily describe the batch experimental data, based on which the equilibrium and kinetic parameters are calculated and compared. The adsorption capacities follow the order of Cu(II) > Pb(II) > Cd(II), due to the complicated impacts of metal ion electronegativity as well as resin pore textures. In the contrast of single and binary adsorption performances, more reduction of Cd(II) than Cu(II) is expectably investigated with the coexistence of competitive ion since the less affinity and hence weak competition of the former onto solid-phase. Using aqueous solution of 15 wt% HCl, nearly 100% recovery of Cu(II) and Cd(II) from IDA-resins could be strictly achieved in the column-tests. Furthermore, a schematic illustration of possible pore structure has been proposed and simulated. Meanwhile, the interaction mechanisms are thereby deduced and evidently confirmed by FT-IR as well as SEM analysis. (C) 2009 Elsevier B.V. All rights reserved.
Keywords: Activated Carbon, Adsorbent, Adsorption, Adsorption Capacities, Adsorption Mechanism, Analysis, Aqueous Solution, Batch, Cadmium, Cd(II), Characteristics, Chelating Resin, Column Tests, Competition, Competitive, Competitive Adsorption, Cu(II), Data, Dynamic, Equilibrium, Exchanger, Experimental, FT-IR, FTIR, Heavy Metal, Heavy Metal Ion, Heavy Metal Ions, Iminodiacetic Acid Group, Impacts, Interaction, Ions, Isotherm, Kinetic, Kinetic Parameters, Langmuir, Langmuir Isotherm, Mechanisms, Metal, Metal Ion, Metal Ions, Pb(II), Physicochemical Structure, Pore-Size, Pseudo Second Order, Pseudo-Second-Order, Pseudo-Second-Order Equation, Recovery, Reduction, Removal, Resin, Resins, Rights, Selectivity, SEM, SEM-EDX, Solution, Sorption, Structure, Waste-Water
? Kim, M.L. and Tudino, M.B. (2010), Evaluation of performance of three different hybrid mesoporous solids based on silica for preconcentration purposes in analytical chemistry: From the study of sorption features to the determination of elements of group IB. Talanta, 82 (3), 923-930.
Full Text: 2010\Talanta82, 923.pdf
Abstract: Several studies involving the physicochemical interaction of three silica based hybrid mesoporous materials with metal ions of the group IB have been performed in order to employ them for preconcentration purposes in the determination of traces of Cu(II), Ag(I) and Au(III). The three solids were obtained from mesoporous silica functionalized with 3-aminopropyl (APS), 3-mercaptopropyl (MPS) and N-[2-aminoethyl]-3-aminopropyl (NN) groups, respectively. Adsorption capacities for Au, Cu and Ag were calculated using Langmuir’s isotherm model and then, the optimal values for the retention of each element onto each one of the solids were found. Physicochemical data obtained under thermodynamic equilibrium and under kinetic conditions - imposed by flow through experiments - allowed the design of simple analytical methodologies where the solids were employed as fillings of microcolumns held in continuous systems coupled on-line to an atomic absorption spectrometry. In order to control the interaction between the filling and the analyte at short times (flow through conditions) and thus, its effect on the analytical signal and the presence of interferences, the initial adsorption velocities were calculated using the pseudo second order model. All these experiments allowed the comparison of the solids in terms of their analytical behaviour at the moment of facing the determination of the three elements. Under optimized conditions mainly given by the features of the filling, the analytical methodologies developed in this work showed excellent performances with limits of detection of 0.14, 0.02 and 0.025 g L-1 and RSD % values of 3.4, 2.7 and 3.1 for Au, Cu and Ag, respectively. A full discussion of the main findings on the interaction metal ions/fillings will be provided. The analytical results for the determination of the three metals will be also presented. (C) 2010 Elsevier B.V. All rights reserved.
? Hazer, O. and Kartal, Ş. (2010), Use of amidoximated hydrogel for removal and recovery of U(VI) ion from water samples. Talanta, 82 (5), 1974-1979.
Full Text: 2010\Talanta82, 1974.pdf
Abstract: Poly(acrylamidoxime-co-2-acrylamido-2-methylpropane sulfonic acid) (PAMSA) hydrogel was prepared by copolymerization of acrylonitrile and 2-acrylamido-2-methylpropane sulfonic acid as monomer, N,N'-methylenebis(acrylamide) as crosslinking agent and potassium peroxodisulfate as initiator. Amidoximated copolymer network was prepared by the reaction of copolymer network with hydroxylamine hydrochloride. A batch procedure was used for the determination of the characteristics of the U(VI) solid phase extraction from the amidoximated hydrogel. The determination of U(VI) was performed by spectrophotometric method using arsenazo-III as complexing agent. Optimal pH value for the quantitative preconcentration was 3, and full desorption was achieved with 3 mol L-1 HClO4. The adsorption process can be well described by the pseudo-second-order kinetic model, and the equilibrium adsorption isotherm was closely fitted with the Langmuir model. A preconcentration factor of 20 and the three sigma detection limit of 2.8 mu g L-1 (n = 20) were achieved for uranium(VI) ions. The PAMSA hydrogel was used for separating and preconcentrating the uranyl ion existing in sea water samples, thermal spring water samples and the certified reference materials (TMDA 64; fortified lake water sample). (C) 2010 Elsevier B.V. All rights reserved.
? Chen, C.Y., Wang, C.H. and Chen, A.H. (2011), Recognition of molecularly imprinted polymers for a quaternary alkaloid of berberine. Talanta, 84 (4), 1038-1046.
Full Text: 2011\Talanta84, 1038.pdf
Abstract: Selective and affinitive imprinted polymers incorporating a quaternary alkaloid of berberine (BER) were prepared using a non-covalent imprinting method. The results showed that, compared to other imprinted polymers, the polymer AD-10 had not only a higher of the ratio of Q(MIP)/Q(BP) for BER adsorption, and but also a larger of the ratio of Q(MIP,B)/Q(MIP,P) for BER and palmatine (PAL) adsorptions. Spectrophotometric analysis demonstrated that a 1:1 cooperative hydrogen-bonding complex might be predominating in the pre-polymerization between the BER template and AA monomer. Adsorption experiments of BER on the polymer AD-10 were in accordance with the second-order and Langmuir adsorption models. The E value (5.70 kJ/mol) calculated from the Dubinin-Radushkevich model indicated that the adsorption followed a physisorption process. In addition, a Scatchard plot showed a single straight line with an equilibrium dissociation constant (K(D)) of 65.80 mu mol/L SPE analyses of a mixture of BER and PAL and the methanol extract from the cortices of Phellodendron wilsonii showed that AD-10 had more efficiency, and higher specificity and selectivity for SPE in the concentration and determination of BER and its extraction from natural products. (C) 2011 Elsevier B.V. All rights reserved.
? Zhu, G.F., Fan, J., Gao, Y.B., Gao, X. and Wang, J.J. (2011), Synthesis of surface molecularly imprinted polymer and the selective solid phase extraction of imidazole from its structural analogs. Talanta, 84 (4), 1124-1132.
Full Text: 2011\Talanta84, 1124.pdf
Abstract: A surface molecularly imprinted polymer (MIP) was synthesized by using imidazole as the template and modified silica particles as the support material. The static adsorption, solid phase extraction (SPE) and high-performance liquid chromatography (HPLC) experiments were performed to investigate the adsorption properties and selective recognition characteristics of the polymer for imidazole and its structural analogs. It was shown that the maximum binding capacities of imidazole on the MIP and the non-imprinted polymer (NIP) were 312 and 169 mu mol g(-1), respectively. The adsorption was fast and the adsorption equilibrium was achieved in 30 min. The binding process could be described by pseudo-second order kinetics. Compared with the corresponding non-imprinted polymer, the molecularly imprinted polymer exhibited much higher adsorption performance and selectivity for imidazole. The selective separation of imidazole from a mixture of 1-hexyl-3-methylimidazolium bromide ([C-6 mim][Br]) and 2,4-dichlorophenol could be achieved on the MIP-SPE column. The recoveries of imidazole and [C-6 mim][Br] were 97.6-102.7% and 12.2-17.3%, respectively, but 2,4-dichlorophenol could not be retained on the column. The surface molecularly imprinted polymer presented here may find useful application as a solid phase absorbent to separate trace imidazole in environmental water samples. This may also form the basis for our research program on the preparation and application of alkyl-imidazolium imprinted polymers. (C) 2011 Elsevier B.V. All rights reserved.
? de Oliveira, F.M., Somera, B.F., Corazza, M.Z., Yabe, M.J.S., Segatelli, M.G., Ribeiro, E.S., Lima, É.C., Dias, S.L.P. and Tarley, C.R.T. (2011), Cellulose microfiber functionalized with N,N’-bis (2-aminoethyl)-1,2-ethanediamine as a solid sorbent for the fast preconcentration of Cd(II) in flow system analysis. Talanta, 85 (5), 2417-2424.
Full Text: 2011\Talanta85, 2417.pdf
Abstract: The present paper describes the synthesis of a new chemically modified cellulose microfiber through oxidation with sodium periodate and functionalization with N,N’-bis (2-aminoethyl)-1,2-ethanediamine for the fast and selective preconcentration of Cd(II) ions in flow system analysis. The new sorbentsorbent was characterized by FTIR, SEM, and surface area values. The uptake behavior of Cd(II) ions onto this sorbent was evaluated from kinetic data, pseudo-first-order and pseudo-second-order models, as well as from Langmuir, Freundlich and Langmuir-Freundlich adsorption isotherms. The maximum sorption capacity of 4.59 mg g-1 was estimated by the Langmuir-Freundlich model with fast kinetics for the sorption of Cd(II) described by the pseudo-second-order kinetic model. After characterization, the sorbent was packed in a mini-column, and a fast flow injection preconcentration system for Cd(II) determination by FAAS was developed. The best Cd(II) preconcentration condition, obtained by means of factorial design and response surface methodology, was achieved at pH 9.36 and a flow rate of 10 mL min-1 followed by elution with 1.0 mol L-1 nitric acid. By using 78s preconcentration time, fast and highly sensitive determination of Cd(II) ions could be achieved with a limit of quantification of 0.2014 L-1, preconcentration factor of 26, consumption index of 0.5 mL, concentration efficiency of 20 min-1, and sample throughput of 39 h-1. The repeatability for 10 replicate determinations was found to be 7.8 and 2.5% for Cd(II) ion concentrations of 5.0 and 100.0 mu g L-1, respectively. The new sorbent efficiency for the interferencefree preconcentration of Cd(II) ions was assessed by analysis of tap, mineral and lake waters, as well as synthetic seawater and normal saline waters. Furthermore, complex samples, such as biological samples, could be analysed by the proposed method in accordance with the accuracy attested by analysis of certified reference materials, TORT-2 (lobster hepatopancreas), and DOLT-4 (dogfish liver). (C) 2011 Elsevier B.V. All rights reserved.
? Zhang, L., Guo, X.J., Li, H.M., Yuan, Z., Liu, X.Y. and Xu, T.C. (2011), Separation of trace amounts of Ga and Ge in aqueous solution using nano-particles micro-column. Talanta, 85 (5), 2463-2469.
Full Text: 2011\Talanta85, 2463.pdf
Abstract: A simple and rapid analytical method for the separation of trace amounts of gallium and germanium from aqueous solution by solid-phase extraction with nano-particles was developed. It was found that only Ga(III) could be quantitatively retained on nano-SiO2 in the pH range of 3-4 and 8-12 while Ge(IV) was not adsorbed, but both Ga(III) and Ge(IV) ions could be adsorbed quantitatively on nano-TiO2 within the pH range of 4-11. These two ions adsorbed by nano-particles could be desorbed quantitatively. Effects of acidity, concentration of elution solution and interfering ions on the recovery of the analytes were systematically investigated. The sorption data could be well interpreted by the Langmuir model. Based on the Langmuir model equation, the monolayer adsorption capacity of nano-SiO2/nano-TiO2 was calculated to be 4.26 mg g-1 /19.68 mgg-1 for Ga(III)/Ge(IV). Moreover, thermodynamic functions, the change of free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) of the adsorption reaction were estimated for each metal ion. Experimental data were also evaluated in terms of kinetic characteristics of adsorption and the adsorption process for both metal ions followed well pseudo-second-order kinetics. Finally, the proposed method was applied to the determination of trace Ga(III) and Ge(IV) in some water samples using loaded nano-particles columns, and it is found that the recoveries of Ga(III) and Ge(IV) were obtained to be in the range of 96.4-105.0%. And the method was validated with certified reference material (GBW07311, GBW 07406) and the values obtained for Ga(III) and Ge(IV) were in good agreement with the certified values. (C) 2011 Elsevier B.V. All rights reserved.