ABSTRACT
PURPOSE: The authors report on the development of a new, noninvasive method to efficiently remove metal ions in aqueous solution flowing in a tube and to quantify the concentrations of those ions. Such a technique could be used to remove toxic ions in the interiors of arteries and veins in patients intoxicated by the ingestion of metal ions. METHODS: A magnetic field is applied to an aqueous electrolyte flowing in a specially designed rectangular cell in order to deflect the ion trajectories and concentrate them at one side of a cell. Once the ions are concentrated, they can be removed. Raman spectroscopy is used to promptly determine the concentration of the removed lead ions. RESULTS: It is possible to increase, on one side of the cell, the ion concentration by more than 80% with respect to the average concentration; the removed ions were taken from this high concentration region. This approach is a rapid, efficient, and noninvasive method for the removal of ions in aqueous solution. Raman spectroscopy was found to be a suitable technique to determine the amount of removed ions. CONCLUSIONS: The results indicate that the ion concentration can be increased more than 80% in a region where they can be removed. The increment in the ion concentration produced by the deflection due to the magnetic field, together with the use of Raman spectroscopy, allows for a rapid analysis of the removed ions without any previous preparation. The proposed method is a potentially useful method for metal ion separation of interest in the medical physics field.
Subject(s)
Electrolytes/chemistry , Lead/isolation & purification , Spectrum Analysis, Raman/methods , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Water/chemistry , Electrolytes/radiation effects , Ions/chemistry , Ions/isolation & purification , Ions/radiation effects , Lead/chemistry , Lead/radiation effects , Magnetic Fields , Radiation Dosage , Reproducibility of Results , Rheology/methods , Sensitivity and Specificity , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/radiation effectsABSTRACT
We present a novel, insoluble, low-generation polyamidoamine (PAMAM)-based polymer. The monomer and polymer were characterized by fourier transform infrared spectroscopy, electrospray ionization mass spectrometry and thermogravimetric measurement, revealing that G0 acryloyl-terminated PAMAM were synthesized and polymerized using ammonium persulfate as an initiator, producing a high-density PAMAM derivative (PAMAM-HD). PAMAM-HD was tested for its ability to remove Na(I), K(I), Ca(II), Mg(II), Cu(II), Mn(II), Cd(II), Pb(II) and Zn(II) ions from acidic, neutral and basic aqueous solutions. PAMAM-HD efficiently removed metals ions from all three solutions. The greatest absorption efficiency at neutral pH was observed against Cu(II), Cd(II) and Pb(II), and the experimental data were supported by the calculated Kd values. Our data could have a significant impact on water purification by providing an inexpensive and efficient polymer for the removal of metal ions.
Subject(s)
Decontamination/methods , Polyamines/chemistry , Polymers/chemical synthesis , Water Purification/methods , Hydrogen-Ion Concentration , Ions/chemistry , Ions/isolation & purification , Mass Spectrometry , Metals/chemistry , Metals/isolation & purification , Molecular Structure , Polymers/chemistry , Spectrophotometry, Atomic , Spectroscopy, Fourier Transform Infrared , Thermogravimetry , Water/chemistryABSTRACT
A study was performed to assess the performance of aminoacids immobilized on carbon nanotubes (CNTs) for their employment as a sorbent for solid phase extraction systems. An immobilization method is introduced and the aminoacid L-tyrosine was chosen as a case study. A spectrophotometric study revealed the amount of aminoacid immobilizated on CNTs surface, and it turned to be of 3174 micromol of L-tyrg(-1). The material was tested for Co retention using a minicolumn inserted in a flow system. At pH 7.0, the amount of Co retained by the column was of 37.58+/-3.06 micromol Co g(-1) of CNTs. A 10% (v/v) HNO(3) solution was chosen as eluent. The pH study revealed that Co binding increased at elevated pH values. The calculation of the mol ratio (moles of Co bound at pH 9 to moles of l-tyr) turned to be 3:1. The retention capacity was compared to other bivalent cations and showed the following tendency: Cu(2+)>Ni(2+)>Zn(2+)>>Co(2+). The analytical performance was evaluated and an enrichment factor of 180 was obtained when 10 mL of 11.37 microg L(-1)Co solution was loaded onto the column at pH 9.0; reaching a limit of detection (LoD) of 50 ng L(-1). The proposed system was successfully applied to Co determination in QC-LL2 standard reference material (metals in natural water).