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Trace Levels Determination of Ammonium by Flow Injection Analysis Using Gas‐Diffusion and Capacitively Coupled Contactless Conductivity Detection
Author(s) -
Braz Henrique L.,
Ito Débora T.,
da Silva José A. Fracassi,
do Lago Claudimir L.,
Pedrotti Jairo J.
Publication year - 2011
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/elan.201100317
Subject(s) - detection limit , thermal conductivity detector , volumetric flow rate , analytical chemistry (journal) , ammonium , conductivity , chemistry , flow injection analysis , diffusion , acceptor , electrode , chromatography , gas chromatography , thermodynamics , organic chemistry , physics , condensed matter physics
A sensitive analytical method based on gas‐diffusion flow injection system for ammonium ion determination at trace levels with capacitively coupled contactless conductivity detection (C 4 D) is described. The effects of the chemical composition of the acceptor stream, operating frequency of the conductivity detector, acceptor and donor flow rates, injected volume, and some potential interferents were evaluated. By injecting 100 µL samples, the analytical method showed linear response for ammonium from 2.0 up to 100 µmol L −1 and a limit of detection of 0.8 µmol L −1 (14 ppb). At a flow rate of 0.10 mL min −1 for the acceptor solution, an analytical throughput of 35 injections per hour was achieved. The new flow injection system was successfully applied for ammonium determination in rainwater from São Paulo city.