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Capillary zone electrophoresis for the analysis of low molecular weight organic acids in environmental systems
Örebro universitet, Institutionen för naturvetenskap.ORCID-id: 0000-0003-4128-8226
2003 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Capillary zone electrophoretic (CZE) methods were developed to identify and quantify low molecular weight (LMW) organic acids in environmental samples. Sensitivity and selectivity were optimised by adapting the background electrolyte to the characteristics of analytes, and by using different modes of detection and injection. Electrokinetic injection mode in combination with an isotachophoretic state increased the sensitivity remarkably for LMW organic acids using UV detection. Calcium ions were added to the background electrolyte, inducing an on-column complexation between acids and calcium ions, which gave good separation of the acids. Mass spectrometric detection (compared to UV detection) increased the sensitivity when using hydrodynamic injection mode during analysis, and selectivity was improved by mass identification. A CZE method for determination of the dissociation constants of LMW organic acids in the pKa range of 3.54.5 was also developed.

The developed procedures were applied to different areas where LMW organic acids play an important environmental role:

Low molecular weight organic acids were analysed in rainwater and soil water in the low μg/l range, within ten minutes after sampling. Rapid analysis and high sensitivity are essential when studying samples with rapid turnover due to microbial activity and photodegradation.

The use of CZE-ESI-MS proved to be a robust analytical tool for determining LMW organic acids in samples rich in interfering ions. Organic acids excreted by soil fungi as response to metal exposure was easily and rapidly quantified with CZE-ESI-MS compared to HPLC and CZE-UV analysis.

Dissociation constants for isosaccharinic acid (ISA) and gluconic acid were determined by CZE to 3.87 and 3.64, respectively. The ability to make the determinations in the presence of impurities as well as not having to know the exact concentration of analyte were identified as the major benefits of CZE.

Isosaccharinic acid was identified as the main degradation product from alkaline degradation of cellulose by CZE analysis. Long-term predictions on both cellulose degradation and ISA production were made based on three years of sampling data. A control sampling after seven years indicated that the degradation of cellulose and the production of ISA were lower than predicted.

sted, utgiver, år, opplag, sider
Örebro: Örebro universitetsbibliotek , 2003. , s. 59
Serie
Örebro Studies in Chemistry, ISSN 1651-4270 ; 2
Emneord [en]
capillary zone electrophoresis, capillary zone electrophoresis-electrospray ionization-mass spectrometry, low molecular weight organic acids, pKa
HSV kategori
Forskningsprogram
Kemi
Identifikatorer
URN: urn:nbn:se:oru:diva-42ISBN: 91-7668-323-0 (tryckt)OAI: oai:DiVA.org:oru-42DiVA, id: diva2:136784
Disputas
2003-01-10, Hörsal Bio, Örebro universitet, Örebro, 10:15
Opponent
Veileder
Tilgjengelig fra: 2003-01-10 Laget: 2003-01-10 Sist oppdatert: 2017-10-18bibliografisk kontrollert
Delarbeid
1. Analysis of low molecular weight organic acids in water with capillary zone electrophoresis employing indirect photometric detection
Åpne denne publikasjonen i ny fane eller vindu >>Analysis of low molecular weight organic acids in water with capillary zone electrophoresis employing indirect photometric detection
2000 (engelsk)Inngår i: Fresenius' Journal of Analytical Chemistry, ISSN 0937-0633, E-ISSN 1432-1130, Vol. 366, nr 5, s. 488-493Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

A capillary zone electrophoretic method for the analysis of low molecular weight carboxylic acids in water was developed. The application uses the chromophore trimellitic acid that allows for indirect photometric detection at 254 nm. Selectivity control by the addition of Ca2+ to the carrier electrolyte made possible a baseline resolved separation of 14 carboxylic acids. Good linearity and repeatability were obtained for both electrokinetic and hydrostatic injection modes. The usefulness of the method is demonstrated by the analysis of a snow sample.

HSV kategori
Forskningsprogram
Kemi
Identifikatorer
urn:nbn:se:oru:diva-15875 (URN)10.1007/s002160050098 (DOI)000086267200015 ()
Tilgjengelig fra: 2011-06-13 Laget: 2011-06-13 Sist oppdatert: 2017-12-11bibliografisk kontrollert
2. Application of capillary zone electrophoresis for the analysis of low molecular weight organic acids in environmental samples
Åpne denne publikasjonen i ny fane eller vindu >>Application of capillary zone electrophoresis for the analysis of low molecular weight organic acids in environmental samples
2000 (engelsk)Inngår i: International Journal of Environmental Analytical Chemistry, ISSN 0306-7319, E-ISSN 1029-0397, Vol. 78, nr 3-4, s. 385-396Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The applicability of a recently developed capillary zone electrophoretic (CZE) method for the determination of low molecular weight (LMW) organic acids in water was tested on five types of environmental samples (rainwater, water extract from peat, and soil water from two polluted sites). A full baseline resolved separation of fourteen commonly found LMW carboxylic acids in natural waters (malonic, oxalic, fumaric, maleic, formic, succinic, tartaric, glutaric, adipic, acetic, propionic, butyric, valeric and citric acids), was achieved within eight minutes. The limits of detection (2 x noise) were in the ranges 90-200 mug/l and 0.5 - 5 mug/l for hydrodynamic and electrokinetic injection, respectively. Two different CZE systems, a Waters Quanta 4000 and a Hewlett Packard HP (CE)-C-3D system, were used and their performance compared.

Emneord
capillary zone electrophoresis, carboxylic acids, environmental samples
HSV kategori
Forskningsprogram
Kemi
Identifikatorer
urn:nbn:se:oru:diva-15874 (URN)10.1080/03067310008041355 (DOI)000167872200015 ()
Tilgjengelig fra: 2011-06-13 Laget: 2011-06-13 Sist oppdatert: 2017-12-11bibliografisk kontrollert
3. Analysis of low molecular weight organic acids using capillary zone electrophoresis-electrospray ionization-mass spectrometry
Åpne denne publikasjonen i ny fane eller vindu >>Analysis of low molecular weight organic acids using capillary zone electrophoresis-electrospray ionization-mass spectrometry
(engelsk)Manuskript (preprint) (Annet vitenskapelig)
HSV kategori
Forskningsprogram
Kemi
Identifikatorer
urn:nbn:se:oru:diva-15893 (URN)
Tilgjengelig fra: 2011-06-14 Laget: 2011-06-14 Sist oppdatert: 2017-10-17bibliografisk kontrollert
4. Organic acids excreted by soil-living fungi as a response to heavy metal (Pb and Cd) stress: Part 1: capillary zone electrophoresis-electrospray ionization-mass spectrometry for quantitative analysis
Åpne denne publikasjonen i ny fane eller vindu >>Organic acids excreted by soil-living fungi as a response to heavy metal (Pb and Cd) stress: Part 1: capillary zone electrophoresis-electrospray ionization-mass spectrometry for quantitative analysis
(engelsk)Manuskript (preprint) (Annet vitenskapelig)
HSV kategori
Forskningsprogram
Kemi
Identifikatorer
urn:nbn:se:oru:diva-15894 (URN)
Tilgjengelig fra: 2011-06-14 Laget: 2011-06-14 Sist oppdatert: 2017-10-17bibliografisk kontrollert
5. Alkaline degradation of cellulose: mechanisms and kinetics
Åpne denne publikasjonen i ny fane eller vindu >>Alkaline degradation of cellulose: mechanisms and kinetics
2003 (engelsk)Inngår i: Journal of polymers and the environment, ISSN 1064-7546, E-ISSN 1572-8900, Vol. 11, nr 2, s. 39-47Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Cellulose powder and softwood sawdust were subjected to alkaline degradation under conditions representative of a cementitious environment for periods of 7 and 3 years, respectively. During the first 3 years, sampling was frequent, and data on the degradation of cellulose and production of isosaccharinic acid was used for establishing long-term prediction models. Samples after an additional period of 4 years were compared to the predicted values. The total rate of degradation was measured as the increase in total organic carbon (TOC) in corresponding solutions. A previously published theoretical model of degradation kinetics gave a good approximation of the present experimental data. Peeling-off, stopping, and alkaline hydrolysis reaction rate constants were obtained as model parameters, and the results suggested that the transformation of the glucose end group is the rate-limiting step in the cellulose peeling-off reaction and also determines the pH dependence of that reaction. After 3 years, isosaccharinic (ISA) acid represented 70-85% of all degradation products as quantified by capillary zone electrophoresis. The long-term prediction model indicated that all of the cellulose would be degraded after only 150-550 years. The control sampling after 7 years points toward a lower degradation of cellulose and production of ISA than predicted by the model, reflecting either a degradation of ISA that was faster than the production or a termination of the ISA production.

Emneord
alkaline degradation of cellulose, isosaccharinic acid, prediction models
HSV kategori
Forskningsprogram
Kemi
Identifikatorer
urn:nbn:se:oru:diva-15872 (URN)10.1023/A:1024267704794 (DOI)000183563800002 ()
Tilgjengelig fra: 2011-06-13 Laget: 2011-06-13 Sist oppdatert: 2017-12-11bibliografisk kontrollert
6. Determination of dissociation constants of low molecular weight organic acids by capillary zone electrophoresis and indirect UV detection
Åpne denne publikasjonen i ny fane eller vindu >>Determination of dissociation constants of low molecular weight organic acids by capillary zone electrophoresis and indirect UV detection
2002 (engelsk)Inngår i: Chromatographia, ISSN 0009-5893, E-ISSN 1612-1112, Vol. 56, nr 9-10, s. 641-644Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

A capillary zone electrophoretic (CZE) method has been developed to determine dissociation constants (pK(a)) for anionic, non-UV absorbing species in the range 3.3-4.3. The procedure was evaluated by determining the ply, for two well-characterised low molecular weight organic acids: formic and lactic acids. The results correspond well with literature values (in parentheses): formic acid 3.71 (3.75) and lactic acid 3.84 (3.85). The pK(a) of two polyhydroxycarboxylic acids were also determined, namely 3.64 for gluconic acid and 3.87 for isosaccharinic acid (only poorly described in the literature).

Emneord
capillary zone electrophoresis, low molecular weight organic acids, dissociation constants, gluconic acid and isosaccharinic acid
HSV kategori
Forskningsprogram
Kemi
Identifikatorer
urn:nbn:se:oru:diva-15873 (URN)10.1007/BF02497683 (DOI)000179246900017 ()
Tilgjengelig fra: 2011-06-13 Laget: 2011-06-13 Sist oppdatert: 2017-12-11bibliografisk kontrollert

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