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Solenoid Micro‐pumps: A New Tool for Sample Introduction in Batch Injection Analysis Systems with Electrochemical Detection
Author(s) -
Rocha Diego P.,
Cardoso Rafael M.,
Mendonça Dianderson M. H.,
Richter Eduardo M.,
da Silva Sidnei G.,
Batista Alex D.,
Muñoz Rodrigo A. A.
Publication year - 2018
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.201700607
Subject(s) - analyte , flow injection analysis , amperometry , working electrode , analytical chemistry (journal) , chromatography , solenoid , electrode , chemistry , dilution , detection limit , materials science , electrolyte , electrochemistry , electrical engineering , physics , thermodynamics , engineering
This work presents the use of solenoid micro‐pumps as a new strategy for sample introduction in batch‐injection analysis (BIA). The volume of solution dispensed on each pulse of the solenoid micro‐pump (μL) is used as fixed and reproducible injection volume for BIA. In this system, the injection steps are possible in stopped flow mode resulting in low background noise levels, which would not be possible under continuous flow conditions and using solenoid micro‐pumps. As a proof‐of‐concept, amperometric and square‐wave voltammetric (SWV) determination of dopamine was demonstrated as well as anodic‐stripping voltammetry (ASV) of metals. The micro‐pump provided injections of 14 μL of solution per pulse at 512 μL s −1 over the electrode during electrochemical measurement. Moreover, fast injections of analyte or electrolyte were programmed during deposition or conditioning steps of ASV for analyte preconcentration or electrode cleaning. The proposed system improved limits of detection and sensitivity (2‐fold), precision and sample throughput in comparison with traditional BIA due to enhanced mass transfer and consequent reduced dispersion of analyte, and possible control of injections without analyst intervention. This work opens new possibilities of applications of the BIA system, including on‐line sample treatment (derivatization or dilution steps).