ISSN:
1433-0768
Schlagwort(e):
Key words Prussian blue
;
Ammonium
;
Voltammetry
;
Flow-through
;
Kjeldahl
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Chemie und Pharmazie
Notizen:
Abstract A new method is described for the determination of ammonium in aqueous solutions with electrodes modified by Prussian blue (PB). The specific voltammetric response of PB-modified electrodes to ammonium ions is used for their analytical determination. In the presence of ammonium ions, a concentration-dependent inhibition of the low-spin iron(II/III) system of PB occurs. Only thallium and rubidium ions cause similar inhibition. A useful electrochemical determination method is thus available for detecting ammonium ions in the presence of frequently interfering potassium and sodium ions. Paraffin-impregnated graphite electrodes modified with a mechanically transferred PB layer and bulk-modified PB-composite electrodes are studied. The method is applicable within a concentration range which extends from 4 × 10−5 mol/l to 10−2 mol/l NH4 +. The composite electrode is used in an electrochemical flow-through system in conjunction with the Kjeldahl method.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/s100080050051
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