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TLS-FIA System For Screening of Dissolved Iron in Ocean Water
Gaja Tomsič, Dorota Korte, Arne Bratkič, Mladen Franko, 2018, published scientific conference contribution abstract

Found in: osebi
Keywords: flow injection analysis, iron concentration, ocean water, thermal lens spectroscopy
Published: 16.07.2018; Views: 2265; Downloads: 0
.pdf Fulltext (679,78 KB)

Determination of iron species in Arctic water by optimized photothermal beam deflection spectroscopy
Hanna Budasheva, Dorota Korte, Arne Bratkič, Mladen Franko, 2018, published scientific conference contribution abstract

Found in: osebi
Keywords: phototermal beam deflection spectroscopy, arctic water, iron species
Published: 16.07.2018; Views: 2132; Downloads: 0
.pdf Fulltext (777,92 KB)

Determination of Dissolved Iron Redox Species in Freshwater Sediment using DGT Technique Coupled to BDS
Yue Gao, Arne Bratkič, Dorota Korte, Aleksander Kravos, Hanna Budasheva, Mladen Franko, 2019, original scientific article

Abstract: 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.
Found in: osebi
Keywords: Beam deflection spectroscopy, diffusive gradients in thin-film technique, iron redox species, photothermal techniques, sediment
Published: 26.02.2019; Views: 1823; Downloads: 71
.pdf Fulltext (452,58 KB)

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: osebi
Keywords: beam deflection spectrometry, diffusive gradients in thin-films, iron species
Published: 16.07.2019; Views: 1440; Downloads: 0
.pdf Fulltext (29,60 MB)

Determination of Iron in Environmental Water Samples by FIA-TLS
Mladen Franko, Arne Bratkič, Dorota Korte, Hanna Budasheva, Leja Goljat, Gaja Tomšič, 2019, original scientific article

Abstract: The determination of low concentration of iron in natural waters can be difficult due to the complexity of natural water, but primarily because it requires preconcentration of the sample with solvent extraction. In this work we report on results of thermal lens spectrometry (TLS) coupled to flow injection analysis (FIA) as a highly sensitive FIA-TLS method of iron detection. The concentration of iron redox species was determined using 1,10-phenanthroline (PHN), that forms stable complexes with Fe(II) ions which are characterized by an absorption maximum at 508 nm. The TLS system using a 633 nm probe laser and 530 nm pump laser beam was exploited for on-line detection in flow injection analysis, where a PHN solution was used as the carrier solution for FIA. The concentration of the complexing agent affects the quality of the TLS signal, and the optimal concentration was found at 1 mM PHN. The achieved limits of detection (LODs) for Fe(II) and total iron were 33 nM for Fe(II) and 21 nM for total iron concentration. The method was further validated by determining the linear concentration range, specificity in terms of analytical yield and by determining concentration of iron in a water sample from a local water stream.
Found in: osebi
Keywords: Flow injection analysis, iron concentration, thermal lens spectroscopy
Published: 18.12.2019; Views: 1304; Downloads: 55
.pdf Fulltext (690,39 KB)

The biogeochemical role of a microbial biofilm in sea ice
Arnout Roukaerts, Florian Deman, Fanny Van der Linden, Gauthier Carnat, Arne Bratkič, Sebastien Moreau, Delphine Lannuzel, Frank Dehairs, B. Delille, Jean-Louis Tison, François Fripiat, 2021, original scientific article

Found in: osebi
Published: 01.09.2021; Views: 183; Downloads: 12
.pdf Fulltext (1,73 MB)
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