scholarly journals A new method based on diffusive gradients in thin films for in situ monitoring microcystin-LR in waters

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Lei Yao ◽  
Alan D. Steinman ◽  
Xiang Wan ◽  
Xiubo Shu ◽  
Liqiang Xie
Keyword(s):  
Thin Films ◽  
Passive Sampling ◽  
Sampling Method ◽  
Binding Capacity ◽  
Accurate Method ◽  
In Situ Monitoring ◽  
Active Sampling ◽  
Binding Agent ◽  
Diffusive Gradients

AbstractThe passive sampling method of diffusive gradients in thin-films (DGT) was developed to provide a quantitative and time-integrated measurement of microcystin-LR (MC-LR) in waters. The DGT method in this study used HLB (hydrophilic-lipophilic-balanced) material as a binding agent, and methanol as an eluent. The diffusion coefficient of MC-LR was 5.01 × 10−6 cm2 s−1 at 25 °C in 0.45 mm thick diffusion layer. This DGT method had a binding capacity of 4.24 μg per binding gel disk (3.14 cm2), ensuring sufficient capacity to measure MC-LR in most water matrices. The detection limit of HLB DGT was 0.48 ng L−1. DGT coupled to analysis by HPLC appears to be an accurate method for MC-LR monitoring. Comparison of DGT measurements for MC-LR in water and a conventional active sampling method showed little difference. This study demonstrates that HLB-based DGT is a useful tool for in situ monitoring of MC-LR in fresh waters.

Application of diffusive gradients in thin-films for in-situ monitoring of nitrochlorobenzene compounds in aquatic environments

2019 ◽  
Vol 157 ◽  
pp. 292-300 ◽  
Author(s):  
Delin Zhang ◽  
Yuanting Zhu ◽  
Xianchuan Xie ◽  
Chao Han ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
In Situ Monitoring ◽  
Aquatic Environments ◽  
Diffusive Gradients

scholarly journals In situ speciation of dissolved inorganic antimony in surface waters and sediment porewaters: development of a thiol-based diffusive gradients in thin films technique for SbIII

2016 ◽  
Vol 18 (8) ◽  
pp. 992-998 ◽  
Author(s):  
William W. Bennett ◽  
Maja Arsic ◽  
David T. Welsh ◽  
Peter R. Teasdale
Keyword(s):  
Thin Films ◽  
Surface Waters ◽  
Sampling Method ◽  
Sediment Porewaters ◽  
Diffusive Gradients

A new in situ sampling method enables the selective measurement of Sb(iii) in surface waters and sediment porewaters.

scholarly journals 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

2021 ◽  
Vol 9 (6) ◽  
pp. 1076-1086
Author(s):  
Arife Şimşek ◽  
Şule Sancak ◽  
Gülfem Bakan
Keyword(s):  
Thin Films ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Black Sea ◽  
Passive Sampling ◽  
Sampling Method ◽  
Grab Sampling ◽  
Metal Concentrations ◽  
Water And Sediment ◽  
Diffusive Gradients

Determining the potential bioavailability of heavy metals, evaluating according to adapted regulations is essential to efficiently conserve our coastal and estuarine waters. In this study, it is aimed to determine the industrial pollution and various other pollution sources that the Black Sea Basin is exposed to by using DGT (Diffusive Gradients in Thin Films) method and grab (manuel) sampling method in water and sediment and to evaluate the existing pollution according to quality standards. In Samsun, seasonal samples were collected from five different sampling stations, namely Akkiraz Stream, Hıdırellez Stream, Organized Industrial Zone (OIZ) Channel, Şabanoğlu Stream and Selyeri Stream, which are selected from Tekkeköy region where industry is intensively active. In order to determine the heavy metal content in both water and sediment samples, the DGT method was chosen for passive sampling and the grab sampling method was used for active sampling, and the efficiency of the methods was evaluated. According to the results of the study, the heavy metal concentration in grab sampling for water samples in descending order Al> Fe> Zn> Pb> Ni> Cu; In the samples taken with DGT, they are listed as Al> Fe> Zn> Cu> Ni> Pb. There were significant relationships between the total metal concentrations of sediment (Csed) and water (Csu) in grab sampling and metal concentrations sediment (Csed-DGT) and water (Csu-DGT) measured by DGT. It was found that the sensitivity and performance of sampling with DGT was 2-10 times higher compared to grab sampling. The high resolution in situ DGT technique for the assessment and management of the potential release risk of heavy metals at the water-sediment interface is a complementary method that contributes to the standard grab sampling method.

Activated Charcoal Based Diffusive Gradients in Thin Films for in Situ Monitoring of Bisphenols in Waters

2014 ◽  
Vol 87 (1) ◽  
pp. 801-807 ◽  
Author(s):  
Jian-Lun Zheng ◽  
Dong-Xing Guan ◽  
Jun Luo ◽  
Hao Zhang ◽  
William Davison ◽  
...  
Keyword(s):  
Thin Films ◽  
Activated Charcoal ◽  
In Situ Monitoring ◽  
Diffusive Gradients

In-situ sampling of available calcium using diffusive gradients in thin-films technique based on benzo-crown ether-functionalised silica as the binding agent

2018 ◽  
Vol 15 (4) ◽  
pp. 205
Author(s):  
Hui Yao ◽  
Nan You ◽  
Hong-Guang Cao ◽  
Li-Xia Kang ◽  
Jin-Bao Wu ◽  
...  
Keyword(s):  
Thin Films ◽  
Crown Ether ◽  
Binding Capacity ◽  
Soil Samples ◽  
Gravimetric Analysis ◽  
Binding Agent ◽  
Grab Sample ◽  
Relative Standard ◽  
Pes Membrane

Environmental contextLow availability of calcium (Ca2+) in soils is one of the major factors in Ca2+ deficiency of plants and physiological plant disorders. A device based on functionalised silica was developed for in-situ measurement of the available Ca2+ in soils. Application of the proposed device to measure available Ca2+ may help to develop and improve agricultural practices. AbstractCalcium is an ion of particular interest due to its importance in plant nutrition and soil structure. A novel device of diffusion gradients in thin-films (DGT) based on the benzo-crown ether-functionalised silica (BCES) as the binding agent and the polyethersulfone (PES) membrane as diffusive layer (BCES-DGT) was developed for in-situ sampling of available calcium (Ca2+) in freshwater and soil samples. The performance characteristics of the BCES-DGT device were assessed. The BCES was prepared using the sol-gel process and characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, thermal gravimetric analysis and N2 adsorption–desorption. Results evinced that BCES was obtained successfully with a rough wrinkled surface and good specific surface area of 111.3 m2 g−1. The diffusion coefficient of Ca2+ ions in PES membrane was found to be 1.23 × 10−6 cm2 s−1 at 25 °C and was independent of pH in the range of 3–10 and ionic strength (as pNaCl) from 1 to 3. The high binding capacity of BCES binding gel for Ca2+ ions was determined to be 9822.4 ± 452.9 μg Ca2+/disk and was conducive to the deployment of long-term or high concentration. The BCES-DGT device can accurately measure the concentrations of Ca2+ over wide ranges of ionic strengths (1–3 as pNaCl) and pH (5–10). There was no significant interference on the uptake of Ca2+ by the BCES-DGT device at the tolerance limits up to 500 for Mg2+, Li+, HCO3−, H2PO4−, NO3− and SO42−, 250 for Sr2+, 2000 for K+ and 50 for fulvic acid. The results from BCES-DGT device were in excellent agreement with those measured directly using ion selective electrode in several water and soil samples. Field application in river water indicated that a good agreement was obtained between BCES-DGT value and mean grab sample measurements of Ca2+ and that the relative standard deviation of BCES-DGT measurement (4.7 %) was superior to that of grab sample measurements (13.5 %), suggesting that BCES-DGT was reliable for in-situ sampling and measurement of available Ca2+ with good accuracy and precision.

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