Knotted Reactors and their Role in Flow‐Injection On‐line Preconcentration Systems Coupled to Atomic Spectrometry‐Based Detectors

Abstract

The progress in flow-injection (FI) on-line separation and preconcentration employing knotted reactors (KRs) as a sorption medium for organometallic complexes associated to atomic spectrometry techniques is reviewed in this article, focusing the attention on the more frequently complexing agents used. In the last years, the KR has demonstrated to be an excellent alternative in the FI on-line preconcentration procedures; the on-line preconcentration and separation of different metallic species on the inner walls of the KR have been developed utilizing diverse organic and inorganic reagents. The choice of complexing reagents, the coupling of the FI preconcentration system to atomic spectrometry techniques, and the application of the methodologies developed to different samples are discussed.

On-line system for preconcentration and determination of metals in vegetables by Inductively Coupled Plasma Optical Emission Spectrometry

“…This situation has been improved significantly by utilizing on-line system coupled with ICP-OES [7][8][9]. Some methodologies used for metal preconcentration have been developed with ionic exchanger resins [10], precipitation [11], cloud point extraction [12][13][14], knotted reactors [15][16][17] and solid-phase extraction [18][19][20][21][22]. In the present work, an on-line procedure for simultaneous preconcentration and determination of Cr, Cu, Ni, Pb and Cd at low concentration levels using ICP-OES is proposed.…”

Determination of copper in biological samples by flame atomic absorption spectrometry after precipitation with Me-BTAP

“…Low solubility in water and capacity to form complexes with a large variety of metals are the characteristics required for the use of these substances in precipitation methods. The precipitation efficiency is highly influenced by the hydrophobicity of ligands and complexes (Cerutti et al 2005;Tokalioglu et al 2007).…”

Integration of Solid-phase Extraction with Electrothermal Atomic Absorption Spectrometry for Determination of Trace Elements

“…In-tube solid-phase microextraction (ITSPME), which does not have a large difference in principle with other FI-SPE techniques using an open tubular column, uses a chemically modified silica capillary tube [39] or a PTFE tube [40] as the solid phase. Since reviews have been published lately [37,38], the on-line coupling of SPE with ETAAS appeared in the most recent papers are described here.…”

“…A polytetrafluoroethylene (PTFE) tube has been used under the name "knotted reactor" [38] . In-tube solid-phase microextraction (ITSPME), which does not have a large difference in principle with other FI-SPE techniques using an open tubular column, uses a chemically modified silica capillary tube [39] or a PTFE tube [40] as the solid phase.…”