CONTINUOUS-FLOW AND FLOW-INJECTION STRIPPING VOLTAMMETRIC DETERMINATION OF SILVER(I), MERCURY(II), AND BISMUTH(III) AT A BULK MODIFIED GRAPHITE TUBE ELECTRODE
Rd. Ye et Sb. Khoo, CONTINUOUS-FLOW AND FLOW-INJECTION STRIPPING VOLTAMMETRIC DETERMINATION OF SILVER(I), MERCURY(II), AND BISMUTH(III) AT A BULK MODIFIED GRAPHITE TUBE ELECTRODE, Electroanalysis, 9(6), 1997, pp. 481-489
The epoxy-impregnated graphite tube electrode bulk modified with 2-mer
captobenzoxazole, employed in a wall-jet configuration, was found to b
e useful for the continuous flow and flow injection stripping voltamme
tric determinations of Ag-I, Hg-II and Bi-III. For continuous flow, de
tection limits for Ag-I, Hg-II and Bi-III were 1.8 x 10(-10) M, 1.9 x
10(-9) M and 9.5 x 10(-9) M, respectively (10min accumulation, S/N = 3
). Precisions for 5.00 x 10(-9) M Ag-I, 1.00 x 10(-8) M Hg-II and 1.00
x 10(-7) M Bi-III were 10.5 %, 5.77 % and 7.90 % (relative standard d
eviations, n = 6), respectively. In the case of flow injection strippi
ng, with a 500 mu L injection loop, detection limits of 0.59 ng, 2.0 n
g and 120 ng were obtained for Ag-I, Hg-II and Bi-III, respectively (S
/N = 3). Selected metal ions, inorganic and organic substances were in
vestigated for interferences. The electrode was tested with a certifie
d sample and then applied to the determinations of the metal ions in a
urine and a sea water sample.