Determination of cadmium in river water samples by flame AAS after on-line preconcentration in mini-column packed with 2-aminothiazole-modified silica gel.
A rapid and sensitive method was developed to determine trace levels of Cd2+ ions in an aqueous medium by flame atomic absorption spectrometry, using on-line preconcentration in a mini-column packed with 100 mg of 2-aminothiazol modified silica gel (SiAT). The Cd2+ ions were sorbed at pH 5.0. The preconcentrated Cd2+ ions were directly eluted from the column to the spectrometer's nebulizer-burner system using 100 microL of 2 mol L(-1) hydrochloric acid. A retention efficiency of over 95% was achieved. The enrichment factor (calculated as the ratio of slopes of the calibration graphs) obtained with preconcentrations in a mini-column packed with SiAT (A = -1.3 x 10(-3) + 1.8 x 10(-3)[Cd2+]) and without preconcentrations (A = 4 x 10(-5) + 3.5 x 10(-5)[Cd2+]), was 51 and the detection limit calculated was 0.38 microg L(-1). The preconcentration procedure was applied to determine trace levels of Cd in river water samples. The optimum preconcentration conditions are discussed herein.
Instituto de Química, Departamento de Química Analítica-UNESP, Araraquara, SP, Brasil.
Ilton L
IL
Alcântara
Paulo S
PS
Roldan
Gustavo R
GR
Castro
Fabrício V
FV
Moraes
Fábio A
FA
Silva
Cilene C F
CC
Padilha
Jorge D
JD
Oliveira
Pedro M
PM
Padilha
D002104:Cadmium / Q000032:analysis* / Q000737:chemistry; D002138:Calibration; D006851:Hydrochloric Acid / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008956:Models, Chemical; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*; D013053:Spectrophotometry; D013054:Spectrophotometry, Atomic / Q000379:methods*; D013055:Spectrophotometry, Infrared; D013844:Thiazoles / Q000494:pharmacology*; D013997:Time Factors; D014867:Water / Q000032:analysis*
D007477:Ions; D013844:Thiazoles; D002104:Cadmium; D014867:Water; C004483:2-aminothiazole; D058428:Silica Gel; D012822:Silicon Dioxide; D006851:Hydrochloric Acid