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1.
Determination of iron in natural waters using DGT technique coupled to phototermal beam deflection spectroscopy
Hanna Budasheva, Arne Bratkič, Dorota Korte, Mladen Franko, 2018, published scientific conference contribution abstract

Found in: ključnih besedah
Summary of found: ...Beam deflection spectroscopy, diffusive gradients in thin-films, iron species, photothermal techniques,...
Keywords: Beam deflection spectroscopy, diffusive gradients in thin-films, iron species, photothermal techniques, natural waters.
Published: 09.11.2018; Views: 1792; Downloads: 0
.pdf Fulltext (40,53 KB)

2.
Determination of bioavailable Fe redox fractions of sediment pore waters by DGT passive sampling and BDS detection
Mladen Franko, Arne Bratkič, Dorota Korte, Hanna Budasheva, 2019, published scientific conference contribution abstract

Abstract: 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.
Found in: ključnih besedah
Summary of found: ...during sampling and storage. In this work the Diffusive Gradients in Thin-films technique (DGT) is investigated...
Keywords: beam deflection spectrometry, diffusive gradients in thin-films, iron species
Published: 16.07.2019; Views: 1541; Downloads: 0
.pdf Fulltext (29,60 MB)

3.
Effect of bead size in Chelex-based resin hydrogels in DGT on detection of Fe redox species by beam deflection spectroscopy
Dorota Korte, Arne Bratkič, Hanna Budasheva, Mladen Franko, 2019, published scientific conference contribution abstract

Found in: ključnih besedah
Summary of found: ... Diffusive Gradients in Thin Films, Beam Deflection Spectrometry,...
Keywords: Diffusive Gradients in Thin Films, Beam Deflection Spectrometry, iron species, resin hydrogels
Published: 25.09.2019; Views: 1444; Downloads: 0
.pdf Fulltext (1,28 MB)

4.
Developing DGT technique for determination of iron redox species by photothermal beam deflection spectrometry
Yue Gao, Dorota Korte, Chang Zhou, Arne Bratkič, Hanna Budasheva, Mladen Franko, Bruno Delille, 2019, published scientific conference contribution abstract

Found in: ključnih besedah
Summary of found: ... Diffusive Gradients in Thin Films, Beam Deflection Spectrometry,...
Keywords: Diffusive Gradients in Thin Films, Beam Deflection Spectrometry, iron redox species
Published: 25.09.2019; Views: 1436; Downloads: 0
.pdf Fulltext (1,28 MB)

5.
Determination of Fe(III) and Fe(II) in natural waters using passive DGT samplers and non-destructive BDS analysis
Arne Bratkič, Dorota Korte, Hanna Budasheva, Mladen Franko, 2019, published scientific conference contribution abstract

Found in: ključnih besedah
Summary of found: ...Beam Deflection Spectrometry, iron species, Diffusive Gradients in Thin-films, frequency scanning...
Keywords: Beam Deflection Spectrometry, iron species, Diffusive Gradients in Thin-films, frequency scanning
Published: 30.09.2019; Views: 1567; Downloads: 0
.pdf Fulltext (19,45 MB)

6.
Towards a novel method for iron species determination in Antarctic sea ice
Hanna Budasheva, Arne Bratkič, Dorota Korte, Mladen Franko, 2021, published scientific conference contribution abstract

Abstract: Sea-ice borne iron has been found to be an important factor controlling Southern Ocean phytoplankton growth [1]. Knowing the amount and chemical speciation of its labile fraction in sea ice would advance our understanding of the involved processes. Unfortunately, it is rather difficult to perform their measurement because of limited access to the Antarctic. Thus there is a strong need for the development of a quick, simple and reliable technique for determination of iron and its speciation in sea-ice that ensures also low enough limits of detection. Recently, diffusive gradients in thin films (DGT) have been widely used as passive samplers for collecting time-averaged data on the concentrations of transition metals in different media [2]. DGTs are further coupled to an analytical technique that in case of detecting metals in passive sampler films primarily requires their extraction [3], which may potentially lead to changes of the metal specification. In the present study, the beam deflection spectrometry (BDS) is coupled to DGT and used to determine the average concentration of iron in the sea ice samples collected at the Davis Station in the Antarctic. Such a combined technique has been already successfully applied for detecting labile iron species in freshwater sediments [4]. The obtained BDS data were validated by thermal lens spectrometry (TLS) and UV-Vis spectrophotometry (SPEC). The distribution of iron species over a given ice surface area using the DGT-BDS technique revealed total iron concentrations in the range of 0.6 – 5.3 μgL-1, whereas the Fe2+ content was found to be in the range of 0.1 – 1.5 μgL-1. The range taking into account all of the measurement points (5×4), the precision of a single measured point is 0.2 μgL-1. The calculated 24 h-average concentration of total Fe labile species in the ice by using BDS is 2.3 ± 0.5 μgL-1, which coincides with data obtained by SPEC (2.5 ± 0.4 μgL-1) and TLS (2.39 ± 0.02 μgL-1). Our results indicate that it is possible to develop a robust, contamination-resilient detection method for measuring the labile iron species concentration in the sea ice. In opposite to TLS and SPEC, BDS-DGT provides reliable information not only about the speciation of iron but also about their distribution on the ice surface.
Found in: ključnih besedah
Summary of found: ...also low enough limits of detection. Recently, diffusive gradients in thin films (DGT) have been...
Keywords: beam deflection spectrometry, diffusive gradients, thin films, iron species, photothermal techniques, Antarctic sea ice
Published: 30.11.2021; Views: 47; Downloads: 0
.pdf Fulltext (216,61 KB)
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