21. Quantitative detection of Microcystis aeruginosa in fresh water using single domain antibodies (VHHs)Gbenga Folorunsho Oginni, Sandra Oloketuyi, Elisa Mazzega, Mladen Franko, Hanna Budasheva, Dorota Korte, Ario De Marco, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: thermal lens spectrometry, nanobodies, fluobodies, cyanobacteria
Objavljeno v RUNG: 18.11.2019; Ogledov: 3582; Prenosov: 122
 Celotno besedilo (15,09 KB) |
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23. Developing DGT technique for determination of iron redox species by photothermal beam deflection spectrometryHanna Budasheva, Arne Bratkič, Chang Zhou, Dorota Korte, Yue Gao, Mladen Franko, Bruno Delille, 2019, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: Diffusive Gradients in Thin Films, Beam Deflection Spectrometry, iron redox species
Objavljeno v RUNG: 25.09.2019; Ogledov: 3378; Prenosov: 0
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26. Determination of bioavailable Fe redox fractions of sediment pore waters by DGT passive sampling and BDS detectionHanna Budasheva, Dorota Korte, Arne Bratkič, Mladen Franko, 2019, objavljeni povzetek znanstvenega prispevka na konferenci Opis: The bioavailability and toxicity of contaminants in sediments to benthic organisms depend on the speciation of the contaminant [1]. The level of iron supply to sediments creates contrasting chemical pathways, each producing distinctive mineral assemblag- es. Reliable measurement of Fe redox species (Fe2+ and Fe3+) in sediments is essential for studies of pollutants or trace-element cycling. This is, however, a difficult task, because the distribution of chemical species often changes during sampling and storage.
In this work the Diffusive Gradients in Thin-films technique (DGT) is investigated as a passive sampling approach used in combination with photothermal beam deflection spectroscopy (BDS) as a detection method for determination of labile Fe-redox species in sediments and natural waters. DGT offers the advantage of pre-concentration of labile (i.e. bioavailable) Fe species from the total dissolved Fe pool in sediment pore waters [2]. The advantage of using BDS [3-4] is also in avoiding contamination by using additional steps as extraction or pre-concentration. Furthermore, combined DGT-BDS provides 2D information about distribution of Fe2+ and the total Fe content in the resin hydrogels [5].
The goal of this research is to show the repeatability of this technique for determining trace amounts of Fe redox species in environmental samples.
Ključne besede: beam deflection spectrometry, diffusive gradients in thin-films, iron species
Objavljeno v RUNG: 16.07.2019; Ogledov: 3396; Prenosov: 0
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27. Photothermal lens technique: a comparison between conventional and self-mixing schemesHumberto Cabrera, Imrana Ashraf, Fatima Matroodi, Evelio E. Ramírez-Miquet, Jehan Akbar, Jose Juan Suárez-Vargas, John Fredy Barrera Ramírez, Dorota Korte, Hanna Budasheva, Joseph J. Niemela, 2019, izvirni znanstveni članek Opis: This work focuses on assessing the analytical capabilities of a new photothermal lens method based on the self-mixing effect to reliably measure metallic traces in water-ethanol solutions. We compare it with the conventional thermal lens scheme, considering the low detection limit and versatility. A theoretical model is presented to describe the laser power variations as a function of the photothermal parameters of the analyzed sample. The experimental results demonstrate that the laser intensity variations, induced by the external optical feedback, are governed by
the photothermal lens effect. Measurements of Fe(II)-1,10-phenanthroline in water–ethanol solutions show a favourable correspondence and agreement with the theory. The low detection limits obtained by the two analytic techniques also agree very well. Nevertheless, our instrument presents advantages regarding compactness and simplicity, suggesting that this platform could be potentially useful as a robust analytical tool for metallic trace detection. In addition, calibration of the method is performed by measuring the so-called self-mixing constant.
Ključne besede: thermal lens, photothermal spectroscopy, self-mixing effect, trace detection
Objavljeno v RUNG: 05.04.2019; Ogledov: 3354; Prenosov: 0
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28. Determination of Dissolved Iron Redox Species in Freshwater Sediment using DGT Technique Coupled to BDSHanna Budasheva, Aleksander Kravos, Dorota Korte, Arne Bratkič, Yue Gao, Mladen Franko, 2019, izvirni znanstveni članek Opis: In this work we have developed a novel method for determination of iron redox species by the use of diffusive gradients in thin-film (DGT) technique coupled to photothermal beam deflection spectroscopy (BDS). The combination of both methods achieved low limit of detection (LOD) of 0.14 μM for Fe (II) ions. The total Fe concentration determined in the Vrtojbica river sediment (Slovenia, Rožna Dolina, 5000 Nova Gorica) was 49.3 μgL–1. The Fe (II) and Fe (III) concentra- tion amounted to 12.8 μgL–1 and 39.9 μgL–1, respectively. Such an approach opens new opportunities for monitoring the content of iron species in natural waters and sediments and provides highly sensitive chemical analysis and an accurate qualitative and quantitative characteristic of the materials under study.
Ključne besede: Beam deflection spectroscopy, diffusive gradients in thin-film technique, iron redox species, photothermal techniques, sediment
Objavljeno v RUNG: 26.02.2019; Ogledov: 3667; Prenosov: 114
Celotno besedilo (452,58 KB) |
29. Optimization of DGT technique for determination of iron species in natural water and sediments by photothermal beam deflection spectroscopyHanna Budasheva, Arne Bratkič, Dorota Korte, Mladen Franko, 2018, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: beam deflection spectroscopy, diffusive gradients in thin-film technique, iron redox species, photothermal techniques, natural water, sediments
Objavljeno v RUNG: 23.11.2018; Ogledov: 3746; Prenosov: 0
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