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Forsgard, Niklas
Publications (4 of 4) Show all publications
Forsgard, N., Sjöberg, P., Bylund, D., Andersson, M. & Pettersson, J. (2007). Screening and identification of aluminium-containing biomolecules by column-switched LC-ICP-MS and LC-ESI-MS/MS. Journal of Analytical Atomic Spectrometry, 22(11), 1397-1402
Open this publication in new window or tab >>Screening and identification of aluminium-containing biomolecules by column-switched LC-ICP-MS and LC-ESI-MS/MS
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2007 (English)In: Journal of Analytical Atomic Spectrometry, ISSN 0267-9477, E-ISSN 1364-5544, Vol. 22, no 11, p. 1397-1402Article in journal (Refereed) Published
Abstract [en]

Column-switching liquid chromatography followed by low resolution ICP-MS was evaluated as a tool for speciation analysis of aluminium-containing biomolecules. The strategy was applied on siderophores, small organic molecules (Mr < 1500) which normally act as strong iron chelators. The drawbacks normally encounterd with aluminium detection using low resolution ICP-MS are the formation of polyatomic ions causing isobaric overlaps and space-charge effects. When adding a carbon rich solvent, such as methanol or acetonitrile, the 13C14N+, 12C15N+ and 12C14N1H+ with the same mass as 27Al+ will form in the plasma. The nitrogen is either entrained from the surrounding atmosphere or added with the constituents in the mobile phase. These disadvantages were successfully counteracted by the use of nitrogen free organic modifier in the mobile phase and the use of cool plasma conditions. Detection limits for standard solutions of aluminium-chelated ferrichrome in sub-nanomolar range were obtained by monitoring the aluminium-27 isotope. The combined use of LC-ICP-MS and LC-ESI-MS/MS was also evaluated as a tool to identify unknown metal complexes, here siderophores, in field soil solution samples. Two aluminium-chelated siderophores, Al-desferrichrom and Al-desferricrocin, were identified and quantified. Both aluminium-siderophore complexes were present in the low nanomolar range (1.1 and 0.7 nM, respectively).

National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-96098 (URN)10.1039/b707948f (DOI)000250399600015 ()
Available from: 2007-09-04 Created: 2007-09-04 Last updated: 2017-12-14Bibliographically approved
Forsgard, N., Nilsson, E., Andersson, M. & Pettersson, J. (2006). Investigation of matrix effects in boron determination using organic solvents as modifiers for liquid chromatography coupled to ICP-MS. Journal of Analytical Atomic Spectroscopy (21), 305-310
Open this publication in new window or tab >>Investigation of matrix effects in boron determination using organic solvents as modifiers for liquid chromatography coupled to ICP-MS
2006 (Swedish)In: Journal of Analytical Atomic Spectroscopy, no 21, p. 305-310Article in journal (Refereed) Published
Identifiers
urn:nbn:se:uu:diva-80762 (URN)doi:10.1039/b513753e (DOI)
Available from: 2006-05-23 Created: 2006-05-23 Last updated: 2011-01-11
Forsgard, N. (2006). Plasma Mass Spectrometry - A Powerful Tool for Speciation Analysis. (Licentiate dissertation).
Open this publication in new window or tab >>Plasma Mass Spectrometry - A Powerful Tool for Speciation Analysis
2006 (English)Licentiate thesis, monograph (Other scientific)
Identifiers
urn:nbn:se:uu:diva-85808 (URN)
Available from: 2007-05-15 Created: 2007-05-15
Liljegren, G., Forsgard, N., Zettersten, C., Pettersson, J., Svedberg, M., Herranen, M. & Nyholm, L. (2005). On-line electrochemically controlled solid-phase extraction interfaced to electrospray and inductively coupled plasma mass spectrometry. The Analyst (130), 1358-1368
Open this publication in new window or tab >>On-line electrochemically controlled solid-phase extraction interfaced to electrospray and inductively coupled plasma mass spectrometry
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2005 (English)In: The Analyst, no 130, p. 1358-1368Article in journal (Refereed) Published
Abstract [en]

Electrochemically controlled solid-phase extractions of anions were interfaced on-line to electrospray mass spectrometry (ESI-MS) and inductively coupled plasma mass spectrometry (ICP-MS), using polypyrrole coated electrodes and a thin-layer electrochemical (EC) flow cell. The results indicate that electrochemically controlled solid-phase extraction (EC-SPE) can be used as a versatile potential controlled sample preparation technique for a range of anions and that the properties of the polypyrrole coatings can be modified by altering the electrodeposition conditions. In the present study, the influence of interfering anions (i.e., fluoride and sulfate), and the anion used during the electropolymerisation, on the bromide extraction recovery was investigated for EC-SPE interfaced to ICP-MS. The results of these experiments show that the interference due to the presence of similar concentrations of sulfate can be reduced when using a polypyrrole coating electropolymerised in the presence of bromide ions. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements were also used to study the morphology of the coatings, as well as the variations in the film thickness within the coatings. The effect of different desorption techniques on the bromide preconcentration factor in the ICP-MS on-line flow system was also examined. Stopped-flow desorption was found to give rise to significantly increased preconcentration factors in comparison with desorptions in flowing solutions. While the desorption efficiency depends on the type of desorption electrolyte (the electrolyte in which the desorption takes place), due to the competing influx of cations, the influence of the pH on the switching charge of the polypyrrole coating was found to be small, at constant ionic strength. To study the applicability of the EC-SPE technique with respect to real samples, investigations were also made with tap water samples spiked with different bromide concentrations. The results of these experiments, which were carried out using a modified thin-layer EC flow cell allowing in situ polymerisation of polypyrrole yielding a polymer plug covering the cross section of the channel, demonstrate that 3 uM concentrations of bromide could be detected in the tap water sample. This demonstrates that the extraction technique allows extractions of low concentrations of ions in the presence of significantly higher concentrations of other similar ions. The fact that the extraction and desorption steps are electrochemically controlled makes EC-SPE particularly well suited for inclusion in miniaturised lab-on-a-chip systems.

National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-74546 (URN)doi:10.1039/b508388e (DOI)
Available from: 2007-03-28 Created: 2007-03-28 Last updated: 2011-01-11
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