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Paulo Cicero Do Nascimento - One of the best experts on this subject based on the ideXlab platform.

  • determination of cadmium lead and thallium in highly saline hemodialysis solutions by potentiometric stripping analysis psa
    Talanta, 2005
    Co-Authors: Paulo Cicero Do Nascimento, Denise Bohrer, Leandro M De Carvalho, Carla Eliete Caon, Eduardo Jorge Pilau, Zilda Baratto Vendrame, Raquel Stefanello
    Abstract:

    Abstract Potentiometric stripping analysis (PSA) was investigated to assay simultaneously cadmium, lead and thallium present as contaminants in highly saline solutions used in hemodialysis. The saline matrices were sodium, potassium, magnesium and Calcium Chlorides, sodium acetate, sodium bicarbonate and glucose, which constitute concentrates for hemodialysis. A 1000 μg mL −1 Hg(II) solution was used to prepare the mercury film electrode (MFE) and to carry out the stripping step. After a 30 s accumulation interval the analytes were simultaneously detected in the saline matrices without using masking agents. Determination limits of 80 ng L −1 for cadmium and thallium, and 50 ng L −1 for lead were calculated and a R.S.D. ranging from 0.5 to 2.2% ( n = 3) was obtained measuring the analytes directly in commercial hemodialysis saline solutions. Recoveries from spiked samples ranging from 94.6 to 102.0% were obtained. The investigated metals were found in concentrations ranging from 2.7 to 5.7 μg L −1 for cadmium, 27.7 to 75.8 μ L −1 for lead and 9.6 to 18.7 μg L −1 for thallium in commercial hemodialysis solutions. The PSA method showed to be adequate to the quality control of saline concentrates for hemodialysis.

  • Electrothermal atomic absorption spectrometric determination of lead, cadmium, copper and zinc in high-salt content samples after simultaneous separation on polyethylene powder impregnated with 1-(2-pyridylazo)-2-naphthol: application to the analysis
    The Analyst, 1999
    Co-Authors: Denise Bohrer, Paulo Cicero Do Nascimento, Marcos V. Guterres, Marcello G. Trevisan, Edson Seibert
    Abstract:

    A simultaneous separation and preconcentration of lead, cadmium, zinc and copper from high-salt content matrices for subsequent electrothermal atomic absorption spectrometric determination was developed. The metals were preconcentrated on a micro-column filled with polyethylene powder impregnated with the complexing agent 1-(2-pyridylazo)-2-naphthol. The determinations, without the interference of the saline matrix, were carried out after metals elution with a small volume of an ethanolic solution of nitric acid. The saline matrices were sodium, potassium, magnesium and Calcium Chlorides, sodium acetate and bicarbonate, which constitute concentrates for hemodialysis. The immobilisation capacity of the complexing agent is about 2.5 µmol per gram of polyethylene and the column capacity with respect to each metal is about 0.75 µmol per gram resin for copper, cadmium and zinc and 0.25 µmol per gram for lead. For the optimisation of the procedure, effects of sample flow rate and pH, eluent composition and concentration, and the influence of salts on the complexation of the metals were investigated. The proposed method was characterised by a precision of about 95% (n = 3) and recoveries from spiked samples of the salts were 81–112%. All results were in agreement with those obtained by anodic stripping voltammetry, the technique used for comparison. The method was applied to the analysis of saline concentrates for hemodialysis, where the investigated metals were found in concentrations between 3.1 µg l–1 for cadmium and 90.5 µg l–1 for zinc.

  • On-line separation and spectrophotometric determination of low levels of aluminum in high-salt content samples: application to analysis of hemodialysis fluids
    Analytica Chimica Acta, 1998
    Co-Authors: Denise Bohrer, Adriana Gioda, Regina Binotto, Paulo Cicero Do Nascimento
    Abstract:

    Abstract An on-line preconcentration and matrix separation procedure for the spectrophotometric determination of low levels of aluminum in aqueous and high-salt content matrices was developed. Aluminum was preconcentrated on polyethylene powder as a complex with Chrome azurol S and, after elution, the complex was spectrophotometrically determined, without interference of the matrix. The assayed salts were sodium, potassium, magnesium and Calcium Chlorides and sodium acetate, usually employed in hemodialysis fluids. A polyethylene powder column was incorporated to the flow system by using a microcolumn as the loop of a six-port valve connected to an injector and to the spectrophotometric detector. Effects of eluent composition and concentration, reactor length and influence of the presence of salts on the preconcentration and elution steps were investigated. The proposed method was characterized by a precision of about 90% and a detection limit of 17 ng Al (6×10 −10  mol). Recoveries from spiked samples of the salts were between 87–110%, and results were in agreement with determinations by graphite furnace atomic absorption spectrometry. The method was applied to the analysis of saline concentrates and water for hemodialysis.

Denise Bohrer - One of the best experts on this subject based on the ideXlab platform.

  • determination of cadmium lead and thallium in highly saline hemodialysis solutions by potentiometric stripping analysis psa
    Talanta, 2005
    Co-Authors: Paulo Cicero Do Nascimento, Denise Bohrer, Leandro M De Carvalho, Carla Eliete Caon, Eduardo Jorge Pilau, Zilda Baratto Vendrame, Raquel Stefanello
    Abstract:

    Abstract Potentiometric stripping analysis (PSA) was investigated to assay simultaneously cadmium, lead and thallium present as contaminants in highly saline solutions used in hemodialysis. The saline matrices were sodium, potassium, magnesium and Calcium Chlorides, sodium acetate, sodium bicarbonate and glucose, which constitute concentrates for hemodialysis. A 1000 μg mL −1 Hg(II) solution was used to prepare the mercury film electrode (MFE) and to carry out the stripping step. After a 30 s accumulation interval the analytes were simultaneously detected in the saline matrices without using masking agents. Determination limits of 80 ng L −1 for cadmium and thallium, and 50 ng L −1 for lead were calculated and a R.S.D. ranging from 0.5 to 2.2% ( n = 3) was obtained measuring the analytes directly in commercial hemodialysis saline solutions. Recoveries from spiked samples ranging from 94.6 to 102.0% were obtained. The investigated metals were found in concentrations ranging from 2.7 to 5.7 μg L −1 for cadmium, 27.7 to 75.8 μ L −1 for lead and 9.6 to 18.7 μg L −1 for thallium in commercial hemodialysis solutions. The PSA method showed to be adequate to the quality control of saline concentrates for hemodialysis.

  • Electrothermal atomic absorption spectrometric determination of lead, cadmium, copper and zinc in high-salt content samples after simultaneous separation on polyethylene powder impregnated with 1-(2-pyridylazo)-2-naphthol: application to the analysis
    The Analyst, 1999
    Co-Authors: Denise Bohrer, Paulo Cicero Do Nascimento, Marcos V. Guterres, Marcello G. Trevisan, Edson Seibert
    Abstract:

    A simultaneous separation and preconcentration of lead, cadmium, zinc and copper from high-salt content matrices for subsequent electrothermal atomic absorption spectrometric determination was developed. The metals were preconcentrated on a micro-column filled with polyethylene powder impregnated with the complexing agent 1-(2-pyridylazo)-2-naphthol. The determinations, without the interference of the saline matrix, were carried out after metals elution with a small volume of an ethanolic solution of nitric acid. The saline matrices were sodium, potassium, magnesium and Calcium Chlorides, sodium acetate and bicarbonate, which constitute concentrates for hemodialysis. The immobilisation capacity of the complexing agent is about 2.5 µmol per gram of polyethylene and the column capacity with respect to each metal is about 0.75 µmol per gram resin for copper, cadmium and zinc and 0.25 µmol per gram for lead. For the optimisation of the procedure, effects of sample flow rate and pH, eluent composition and concentration, and the influence of salts on the complexation of the metals were investigated. The proposed method was characterised by a precision of about 95% (n = 3) and recoveries from spiked samples of the salts were 81–112%. All results were in agreement with those obtained by anodic stripping voltammetry, the technique used for comparison. The method was applied to the analysis of saline concentrates for hemodialysis, where the investigated metals were found in concentrations between 3.1 µg l–1 for cadmium and 90.5 µg l–1 for zinc.

  • On-line separation and spectrophotometric determination of low levels of aluminum in high-salt content samples: application to analysis of hemodialysis fluids
    Analytica Chimica Acta, 1998
    Co-Authors: Denise Bohrer, Adriana Gioda, Regina Binotto, Paulo Cicero Do Nascimento
    Abstract:

    Abstract An on-line preconcentration and matrix separation procedure for the spectrophotometric determination of low levels of aluminum in aqueous and high-salt content matrices was developed. Aluminum was preconcentrated on polyethylene powder as a complex with Chrome azurol S and, after elution, the complex was spectrophotometrically determined, without interference of the matrix. The assayed salts were sodium, potassium, magnesium and Calcium Chlorides and sodium acetate, usually employed in hemodialysis fluids. A polyethylene powder column was incorporated to the flow system by using a microcolumn as the loop of a six-port valve connected to an injector and to the spectrophotometric detector. Effects of eluent composition and concentration, reactor length and influence of the presence of salts on the preconcentration and elution steps were investigated. The proposed method was characterized by a precision of about 90% and a detection limit of 17 ng Al (6×10 −10  mol). Recoveries from spiked samples of the salts were between 87–110%, and results were in agreement with determinations by graphite furnace atomic absorption spectrometry. The method was applied to the analysis of saline concentrates and water for hemodialysis.

J Bello - One of the best experts on this subject based on the ideXlab platform.

  • a mixture of potassium magnesium and Calcium Chlorides as a partial replacement of sodium chloride in dry fermented sausages
    Journal of Agricultural and Food Chemistry, 1998
    Co-Authors: Olga Gimeno, Iciar Astiasaran, J Bello
    Abstract:

    A mixture of 1.00% NaCl, 0.55% KCl, 0.23% MgCl2, and 0.46% CaCl2 was used to replace the NaCl in dry fermented sausages. Sodium content decreased from 1.88 in the control (made with 2.6% of NaCl) to 0.91 g/100 g in the modified products. The increases in potassium, magnesium, and Calcium were from 0.55 to 1.11 g of K/100 g, from 25.60 to 182.00 mg of Mg/100 g, and from 82.60 to 182.90 mg of Ca/100 g. The mixture of salts gave rise to a greater acidification and water activity. No effects were found in the lactic acid bacteria counts but a decrease of Micrococcaceae was observed. Furthermore a decrease in nitroso heme pigments was found in the final products made with this mixture of salts. Sensorial acceptability was lower mainly due to the lower salty taste. Keywords: Fermented sausages; salt substitution; chloride salts; nutritional advantages

Edson Seibert - One of the best experts on this subject based on the ideXlab platform.

  • Electrothermal atomic absorption spectrometric determination of lead, cadmium, copper and zinc in high-salt content samples after simultaneous separation on polyethylene powder impregnated with 1-(2-pyridylazo)-2-naphthol: application to the analysis
    The Analyst, 1999
    Co-Authors: Denise Bohrer, Paulo Cicero Do Nascimento, Marcos V. Guterres, Marcello G. Trevisan, Edson Seibert
    Abstract:

    A simultaneous separation and preconcentration of lead, cadmium, zinc and copper from high-salt content matrices for subsequent electrothermal atomic absorption spectrometric determination was developed. The metals were preconcentrated on a micro-column filled with polyethylene powder impregnated with the complexing agent 1-(2-pyridylazo)-2-naphthol. The determinations, without the interference of the saline matrix, were carried out after metals elution with a small volume of an ethanolic solution of nitric acid. The saline matrices were sodium, potassium, magnesium and Calcium Chlorides, sodium acetate and bicarbonate, which constitute concentrates for hemodialysis. The immobilisation capacity of the complexing agent is about 2.5 µmol per gram of polyethylene and the column capacity with respect to each metal is about 0.75 µmol per gram resin for copper, cadmium and zinc and 0.25 µmol per gram for lead. For the optimisation of the procedure, effects of sample flow rate and pH, eluent composition and concentration, and the influence of salts on the complexation of the metals were investigated. The proposed method was characterised by a precision of about 95% (n = 3) and recoveries from spiked samples of the salts were 81–112%. All results were in agreement with those obtained by anodic stripping voltammetry, the technique used for comparison. The method was applied to the analysis of saline concentrates for hemodialysis, where the investigated metals were found in concentrations between 3.1 µg l–1 for cadmium and 90.5 µg l–1 for zinc.

Olga Gimeno - One of the best experts on this subject based on the ideXlab platform.

  • a mixture of potassium magnesium and Calcium Chlorides as a partial replacement of sodium chloride in dry fermented sausages
    Journal of Agricultural and Food Chemistry, 1998
    Co-Authors: Olga Gimeno, Iciar Astiasaran, J Bello
    Abstract:

    A mixture of 1.00% NaCl, 0.55% KCl, 0.23% MgCl2, and 0.46% CaCl2 was used to replace the NaCl in dry fermented sausages. Sodium content decreased from 1.88 in the control (made with 2.6% of NaCl) to 0.91 g/100 g in the modified products. The increases in potassium, magnesium, and Calcium were from 0.55 to 1.11 g of K/100 g, from 25.60 to 182.00 mg of Mg/100 g, and from 82.60 to 182.90 mg of Ca/100 g. The mixture of salts gave rise to a greater acidification and water activity. No effects were found in the lactic acid bacteria counts but a decrease of Micrococcaceae was observed. Furthermore a decrease in nitroso heme pigments was found in the final products made with this mixture of salts. Sensorial acceptability was lower mainly due to the lower salty taste. Keywords: Fermented sausages; salt substitution; chloride salts; nutritional advantages