On-line dialysis of some metal ions and metal complexes

Martins, E.; Bengtsson, Mats; Johansson, Gillis

doi:10.1016/s0003-2670(00)86204-2

Cited by 20 publications

(2 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Investigation of Chemical Effects. Progress in dialysis as a membrane separation technique in flow systems has been rather slow since it is traditionally regarded as a poorly defined process whose efficiency depends strongly on variables that are difficult to maintain or reproduce. , The dependence of the permeation rate of ionic species on concomitant electrolytes in the sample medium causes different dialysate concentrations for the same concentration of target analyte . In sandwich-type dialyzers with continuous flow of both recipient and donor streams, chemical effects due to the sample medium itself can be effectively suppressed on-line by merging the feeding stream with an additional ionic strength buffer, thus ensuring the balance of the chemical potential in the donor stream for both sample and standard solutions. ,, This strategy was, however, inappropriate for probe-type microdialyzers inserted in aqueous or solid environmental samples or living tissues, since modification of the matrix composition is obviously not viable.…”

Section: Resultsmentioning

confidence: 99%

Implantable Flow-Through Capillary-Type Microdialyzers for Continuous in Situ Monitoring of Environmentally Relevant Parameters

Miró

Frenzel

2004

Anal. Chem.

View full text Add to dashboard Cite

In this paper, a simple, flexible, and cost-effective flow-through microdialyzer hyphenated with a miniaturized differential potentiometric detector is proposed for continuous diffusion-controlled sampling of analytes of environmental interest. The analytical performance of the dedicated configuration involving merely a single cellulose regenerated hollow fiber is critically compared with that of commercially available concentric probes commonly exploited for in vivo monitoring of the extracellular space in living tissues and that of large dialysis-based probes furnished with flat membranes. The outstanding feature of the capillary-type design is the ability of adapting the extraction fractions (EF) to the requirements of the assays and flow-through detectors by selection of appropriate membrane length/perfusion rate ratios. Passive sampling under steady-state conditions (EF approximately 100%) has proven feasible for environmentally relevant ions, such as chloride, by perfusing a 3-cm-long capillary with water at a flow rate of 2.0 microL/min. Hence, there is no need for recalibration of the flow setup after implantation of the purpose-made probe. The effect of physical and chemical variables on the diffusive flux is discussed in detail for the various flow-through membrane separation devices assessed. Effective means to attain identical dialysate concentrations of target species under dynamic regime irrespective of the matrix ingredients are also presented. The dedicated microdialyzer features extreme tolerance to high molecular weight interfering matrix compounds (> or =5000 mg/L humic acid) at the 5% interference level, which makes it especially suited for the interference-free potentiometric determination of ionic species in environmental samples containing high levels of organic matter. The potentials of the membrane separation unit were assessed for continuous monitoring of chemical changes in the interstitial/pore water of organic soils via stimulus-response strategies.

show abstract

Section: Resultsmentioning

confidence: 99%

Implantable Flow-Through Capillary-Type Microdialyzers for Continuous in Situ Monitoring of Environmentally Relevant Parameters

Miró

Frenzel

2004

Anal. Chem.

View full text Add to dashboard Cite

show abstract

“…Martins et al [96] studied the effect of ionic strength, pH and complexing ligands on the on-line dialysis of metal ions, particularly Zn, using an FIA system. Theoretical studies with different dialysis membranes for this ion were reported by Bernhardsson et al [97].…”

Section: Sampling Systemsmentioning

confidence: 99%

State of the art in on‐line techniques coupled to flow injection analysis FIA/on‐line‐ a critical review

Puchades

Maquieira

Atienza

et al. 1990

Journal of Analytical Methods in Chemistry

View full text Add to dashboard Cite

Flow injection analysis (FIA) has emerged as an increasingly used laboratory tool in chemical analysis. Employment of the technique for on-line sample treatment and on-line measurement in chemical process control is a growing trend. This article reviews the recent applications of FlA. Most papers refer to on-line sample treatment. Although FIA is very well suited to continuous on-line process monitoring, few examples have been found in this areamost of them have been applied to water treatment or fermentation processes.

show abstract