Premium
The Influence of Diffusion Fluxes on the Detection Limit of the Jalpaite Copper Ion‐Selective Electrode
Author(s) -
Zirino Alberto,
De Marco Roland,
Rivera Ignacio,
Pejcic Bobby
Publication year - 2002
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/1521-4109(200204)14:7/8<493::aid-elan493>3.0.co;2-c
Subject(s) - detection limit , electrode , copper , analytical chemistry (journal) , chemistry , diffusion , dissolution , diffusion layer , saturation (graph theory) , ion , chromatography , thermodynamics , physics , mathematics , organic chemistry , combinatorics
It has been suggested that electrode dissolution and the concomitant saturation of the electrode's diffusion layer restricts the detection limit of the jalpaite Cu ion‐selective electrode (ISE) to samples with total Cu levels above 10 −6 mol dm −3 [1, 2]. This article will use rotating disk electrode (RDE) data for San Diego Bay seawater and Fick's law of diffusion to demonstrate that the static commercial Orion Cu ISE (employing a jalpaite membrane) produces a background level of contamination of (2.0±0.5)×10 −8 mol dm −3 total Cu, and the reduced thickness of the Orion Cu ISE's diffusion layer in the presence of hydrodynamic flow [e. g., at an RDE, or in continuous flow analysis (CFA)] lowers the background contamination of Cu to <10 −9 mol dm −3 . Furthermore, the RDE Cu ISE employing an electrode fabricated using jalpaite precipitated in 80% excess Na 2 S, so as to minimize the presence of occluded and leachable Cu 2+ salts and extraneous phases such as silver sulfide [3–5], reveals an improvement in the lower limit of detection compared to the commercial Orion Cu ISE.