Determination of Dissolved Iron Redox Species in Freshwater Sediment using DGT Technique Coupled to BDS

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) concentration 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.

Recent Progress and Applications of Thermal Lens Spectrometry and Photothermal Beam Deflection Techniques in Environmental Sensing

“…Such a sampler consists of a filter layer, an agarose polyacrylamide (APA) diffusive gel, and a resin gel (binding gel), which selectively binds metals and their species (free ions, labile complexes). Such a passive sampler is assembled as described previously for the determination of iron species in river sediments [ 26 ] and deployed for a fixed period of time in waters and sediments or simply laid on top of the cut ice core to accumulate ions in its binding gel.…”

“…Each gel was cut into four smaller pieces (approximately 1 cm by 1.5 cm each) to fit into the BDS spectrometer. Each piece of binding gel was treated as described above in Section 3.4 and in our previous work [ 26 ]. The concentration of Fe(II) or total Fe was determined by performing measurements at nine measurement points on each piece of gel, with an about 3 mm lateral resolution, scanning the entire surface of the gel actually.…”

“…Several other applications of TLS in the analysis of environmental and related samples can be found in previous review papers and book chapters [ 20 , 21 , 22 , 23 , 24 , 25 ]. On the other hand, the number of applications of BDS for analysis and characterization of environmental samples is quite limited and, so far, related mainly to the characterization of diffusive gradient thin film (DGT) based passive samplers and speciation of iron in sediments [ 26 ] and to the determination of H 2 S by exploiting beam deflection in response to temperature variations above plasmonic nanostructures resulting from adsorption of the analyte on Au nanoparticles [ 27 ]. A microcantilever sensor based on BDS, which provides a miniature sensing platform for the real-time, simultaneous detection of multiple target analytes using a single device, was also proposed and offered potential applications in environmental sensing as well [ 28 ].…”

Monitoring of Heavy Metal Pollution in Water and Sediments at the Mid-Black Sea Region by Using Passive Sampling Method Diffusive Gradients in Thin Films

“…This technique requires a specially designed passive sampler containing a binding gel, spreading gel, and membrane filter (Zhang and Davidson, 1999). water (Budasheva et al, 2019;Chaudhary et al, 2020) The element or compound passes through the membrane filter and diffusive gel and is rapidly assimilated by the binding gel. Post-dispensing analysis of the binding gel can be used to determine the bulk solution concentration of the element or compound in a simple equation.…”

“…Figure 1. a) DGT and its parts used in sediment b) used inwater(Budasheva et al, 2019;Chaudhary et al, 2020) …”