Solid phase extraction of Co ions using L-tyrosine immobilized on multiwall

PABLO H. PACHECO, PATRICIA SMICHOWSKI, GRISELDA POLLA, LUIS D. MARTINEZ

TALANTA

ELSEVIER SCIENCE BV

Año: 2009 p. 249 - 253

0039-9140

Astudywas 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-tyrosinewas chosen as a case study. A spectrophotometric study revealed the amount of aminoacid immobilizated on CNTs surface, and it turned to be of 3174mol of L-tyr g-1. The material was tested for Co retention using a minicolumn inserted in a .ow system. At pH 7.0, the amount of Co retained by the column was of 37.58±3.06mol Co g-1 of CNTs. A 10% (v/v) HNO3 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: Cu2+ >Ni2+ >Zn2+Co2+. The analytical performance was evaluated and an enrichment factor of 180 was obtained when 10mL of 11.37gL-1 Co solution was loaded onto the column at pH 9.0; reaching a limit of detection (LoD) of 50 ng L-1. The proposedsystemwas successfully appliedtoCodetermination in QC-LL2 standardreference material (metals in natural water).L-tyrosinewas chosen as a case study. A spectrophotometric study revealed the amount of aminoacid immobilizated on CNTs surface, and it turned to be of 3174mol of L-tyr g-1. The material was tested for Co retention using a minicolumn inserted in a .ow system. At pH 7.0, the amount of Co retained by the column was of 37.58±3.06mol Co g-1 of CNTs. A 10% (v/v) HNO3 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: Cu2+ >Ni2+ >Zn2+Co2+. The analytical performance was evaluated and an enrichment factor of 180 was obtained when 10mL of 11.37gL-1 Co solution was loaded onto the column at pH 9.0; reaching a limit of detection (LoD) of 50 ng L-1. The proposedsystemwas successfully appliedtoCodetermination in QC-LL2 standardreference material (metals in natural water).L-tyr g-1. The material was tested for Co retention using a minicolumn inserted in a .ow system. At pH 7.0, the amount of Co retained by the column was of 37.58±3.06mol Co g-1 of CNTs. A 10% (v/v) HNO3 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: Cu2+ >Ni2+ >Zn2+Co2+. The analytical performance was evaluated and an enrichment factor of 180 was obtained when 10mL of 11.37gL-1 Co solution was loaded onto the column at pH 9.0; reaching a limit of detection (LoD) of 50 ng L-1. The proposedsystemwas successfully appliedtoCodetermination in QC-LL2 standardreference material (metals in natural water).±3.06mol Co g-1 of CNTs. A 10% (v/v) HNO3 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: Cu2+ >Ni2+ >Zn2+Co2+. The analytical performance was evaluated and an enrichment factor of 180 was obtained when 10mL of 11.37gL-1 Co solution was loaded onto the column at pH 9.0; reaching a limit of detection (LoD) of 50 ng L-1. The proposedsystemwas successfully appliedtoCodetermination in QC-LL2 standardreference material (metals in natural water).L-tyr) turned to be 3:1. The retention capacity was compared to other bivalent cations and showed the following tendency: Cu2+ >Ni2+ >Zn2+Co2+. The analytical performance was evaluated and an enrichment factor of 180 was obtained when 10mL of 11.37gL-1 Co solution was loaded onto the column at pH 9.0; reaching a limit of detection (LoD) of 50 ng L-1. The proposedsystemwas successfully appliedtoCodetermination in QC-LL2 standardreference material (metals in natural water).2+ >Ni2+ >Zn2+Co2+. The analytical performance was evaluated and an enrichment factor of 180 was obtained when 10mL of 11.37gL-1 Co solution was loaded onto the column at pH 9.0; reaching a limit of detection (LoD) of 50 ng L-1. The proposedsystemwas successfully appliedtoCodetermination in QC-LL2 standardreference material (metals in natural water).-1 Co solution was loaded onto the column at pH 9.0; reaching a limit of detection (LoD) of 50 ng L-1. The proposedsystemwas successfully appliedtoCodetermination in QC-LL2 standardreference material (metals in natural water).-1. The proposedsystemwas successfully appliedtoCodetermination in QC-LL2 standardreference material (metals in natural water).