Ham. Elmahadi et Gm. Greenway, IMMOBILIZED CYSTEINE AS A REAGENT FOR PRECONCENTRATION OF TRACE-METALS PRIOR TO DETERMINATION BY ATOMIC-ABSORPTION SPECTROMETRY, Journal of analytical atomic spectrometry, 8(7), 1993, pp. 1011-1014
A flow injection system combining on-line preconcentration using immob
ilized cysteine with atomic spectrometric detection was developed for
the determination of trace metals. The chelating reagent, cysteine, wa
s immobilized on controlled pore glass. The amino group of cysteine wa
s used to covalently bind it to silanized controlled pore glass throug
h the bifunctional reagent glutaraldehyde. The immobilized reagent was
then packed into a mini-column and used for the preconcentration of t
race metals in a flow system with atomic absorption spectrometric dete
ction. The immobilized reagent was used to preconcentrate copper, zinc
, cadmium, lead, cobalt and mercury in aqueous acidic media with capac
ities of 7.86, 7.88,12.48,11.66,5.50 and 6.06 mmol g-1 of the dry resi
n, respectively. The pH dependence of the extraction of the metal ions
by the resin, the type of eluent utilized, the column length and flow
rate were evaluated. The effect of interference from other metal ions
was investigated. The sampling frequency was 20 h-1.