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- Dahlén, Johan, et al.
(författare)
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Analysis of low molecular weight organic acids in water with capillary zone electrophoresis employing indirect photometric detection
- 2000
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Ingår i: Fresenius' Journal of Analytical Chemistry. - : Springer Science and Business Media LLC. - 0937-0633 .- 1432-1130. ; 366:5, s. 488-493
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Dahlén, Johan, et al.
(författare)
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Determination of nitrate and other water quality parameters in groundwater from UV/Vis spectra employing partial least squares regression
- 2000
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Ingår i: Chemosphere. - : Pergamon Press. - 0045-6535 .- 1879-1298. ; 40:1, s. 71-77
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Tidskriftsartikel (refereegranskat)abstract
- The use of UV/Vis spectroscopy in combination with partial least squares (PLS) regression for the simultaneous prediction of nitrate and non-purgeable organic carbon (NPOC) in groundwaters was evaluated. A model of high quality was obtained using first order derivative spectra in the range 200–300 nm. Inclusion of non-UV-absorbing constituents in the modeling procedure, i.e., chloride, sulfate, fluoride, total carbon (TC), inorganic carbon (IC), alkalinity, pH and conductivity was also evaluated. This model seemed to be useful for prediction of chloride, TC, IC, alkalinity and conductivity, while its ability to predict sulfate, fluoride and pH was poor. In conclusion, application of PLS regression, which requires neither filtration of samples nor addition of chemicals, is a promising alternative for fast interpretation of geochemical patterns of groundwater quality.
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| 4. |
- Hagberg, Jessika, et al.
(författare)
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Application of capillary zone electrophoresis for the analysis of low molecular weight organic acids in environmental samples
- 2000
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Ingår i: International Journal of Environmental Analytical Chemistry. - : Informa UK Limited. - 0306-7319 .- 1029-0397. ; 78:3-4, s. 385-396
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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