title: On-line preconcentration and determination of lead and cadmium by sequential injection/anodic stripping voltammetry.
abstract: The highly sensitive determination of lead (Pb(II)) and cadmium (Cd(II)) ions, with a limit of detection of 0.01μgL(-1) for Pb(II) and Cd(II), by on-line preconcentration and anodic stripping voltammetry (ASV) controlled by a sequential injection analysis (SIA) system is reported here. The SIA system consisted of a syringe pump, an 8-port selection valve and a 6-port switching valve and was incorporated with a bismuth coated screen-printed carbon nanotube electrode (Bi-SPCNTE). The preconcentration of metal ions was performed by solid phase extraction using an Analig TE-05 chelating resin mini-column on a switching valve. The metal ions collected were then eluted from the resin with 1M hydrochloric acid (HCl), deposited on the electrode surface at -1.3V vs. Ag/AgCl and then measured with ASV. The pH of the sample, eluent volume, flow rate, concentration of the bismuth plating solution and the square-wave voltammetric parameters were optimized. Under the optimum conditions, an enrichment factor of 11.9-fold and 6.6-fold for Pb(II) and Cd(II) ions, respectively, was attained. Detection of Pb(II) and Cd(II) had two different linear ranges (0.5-15μgL(-1) and 15-70μgL(-1)).
authors: Electrochemistry and Optical Spectroscopy Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok, 10330, Thailand.
authors: Benjawan
authors: B
authors: Ninwong
authors: Suchada
authors: S
authors: Chuanuwatanakul
authors: Orawon
authors: O
authors: Chailapakul
authors: Wijitar
authors: W
authors: Dungchai
authors: Shoji
authors: S
authors: Motomizu
mesh_terms: D053000:Analytic Sample Preparation Methods / Q000379:methods*; D000818:Animals; D001628:Beverages / Q000032:analysis; D001729:Bismuth / Q000737:chemistry; D002104:Cadmium / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004785:Environmental Pollutants / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D017022:Flow Injection Analysis / Q000379:methods*; D005504:Food Analysis; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D037742:Nanotubes, Carbon / Q000737:chemistry; D009862:Online Systems; D014867:Water / Q000737:chemistry
chemical_list: D004785:Environmental Pollutants; D037742:Nanotubes, Carbon; D002104:Cadmium; D014867:Water; D007854:Lead; D001729:Bismuth