TALANTA
·
2018
·
IF 4.244
Zhongmin Feng,Ni Wang,Manli He,Lan Yang,Yun Wang,Ting Sun
A new diffusive gradients in thin films (DGT) technique with a micro-sized biochar-zeolite-zirconium oxide mixed binding phase is described for simultaneous sampling of dissolved orthophosphate and ammonium in freshwaters. The performance of mixed binding layer (MBL) DGT technique was characterized by evaluation of the following parameters: (1) the adsorption efficiency of phosphate and ammonium by the mixed binding phase, (2) the elution efficiency, (3) the time-series accumulation, and (4) the influences of pH, coexisting cations and DOC on DGT uptake. The mixed binding phase had high uptake for both phosphate and ammonium. The accumulated analyte mass increased linearly with time over 48 h ( Δ g = 1.3 mm) and 84 h ( Δ g = 1.9 mm), respectively. Simultaneous sampling of phosphate and ammonium using MBL-DGT was consistent over the 10–80 mg C L −1 DOC concentration range and the 3–8 pH range for a 24 h deployment. The coexisting cations (Na + , K + , Mg 2+ , and Ca 2+ ) were found to compete with the ammonium accumulation by MBL-DGT, but ammonium accumulation was consistent over concentration ranges typically found in most freshwaters (up to 0.01 mol L −1 Na + , 0.001 mol L −1 K + , 0.01 mol L −1 Mg 2+ , 0.03 mol L −1 Ca 2+ ). The MBL-DGT method also performed predictably in natural freshwaters containing different concentrations of metal ions and dissolved organic carbon. The results of this project have demonstrated that this new DGT method can offer a more cost-efficient method for simultaneously determining time-weighted average concentrations of ammonium and dissolved orthophosphate in most freshwaters, but inefficiently in high salinity waters because of its extremely high concentration of competing cations.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Technology & Innovation
·
2024
·
IF 6.7
Dong-Xing Guan,Tian-Jiao Wei,Guang-Hui Yu,Jun Luo,Gang Li
Silicon is an essential component of various environmental processes and biogeochemical cycles with silicate (H 4 SiO 4 ) representing the bioavailable form of silicon in waters and soils. This study aimed to develop a method for accurately measuring labile silicate levels in waters and soils using diffusive gradients in thin-films (DGT) with a hydrogel diffusive gel and a modified precipitated zirconia (mPZ) binding gel. The diffusion coefficient of silicate in the diffusive gel, measured using an independent diffusion cell, was 6.77 × 10 −6 cm 2 s −1 at 25 °C. The mPZ gels were found to be effective at quickly and efficiently binding silicate, and a mixed solution of 0.5 mol L −1 NaOH and 0.5 mol L −1 H 2 O 2 was determined to effectively elute silicate from mPZ gels, with an elution factor of 1.0. Furthermore, mPZ-DGT was found to be able to measure silicate at various pH levels (4.03–7.93) and ionic strengths (0.1–1000 mmol L −1 NaNO 3 ). Field application of mPZ-DGT devices in an urban river revealed a decrease in silicate concentration downstream compared to upstream, likely due to increased human activity. Finally, mPZ-DGT was used in four sandy or loam soils to measure silicate concentration, and the results showed relatively small variations compared to those measured by CaCl 2 and ammonium oxalate extractions. The findings suggest that mPZ-DGT is a useful tool for monitoring labile silicate concentrations and assessing its bioavailability in waters and soils.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2024
·
IF 5.7
Zhou Fang,Ying Su,Yaqin Yu,Huaijian Zhang,Xintian Qian
Diffusive Gradients in Thin-films (DGT) technique is a promising passive sampling technique, which was used for the determination of lots of inorganic and organic pollutants. Although many DGT devices have not been extensively tested and verified in field, DGT device such as LSNP-NP, LSNT-NP, LSNZ-NP, and LSNM-NP DGT were widely employed for the assessment of various trace elements. However, the deployment time of these DGTs were much shorter than the theoretical time in the preexisting literature. Therefore, the performance of DGT for long-term application in different water bodies is not known. This investigation utilized the four DGTs for the assessment of various trace elements across extended periods both in controlled laboratory settings and natural field environments. Synthetic soft, hard, and seawater compositions served as media for laboratory deployments. Most elements can be measured accurately in 4–7 days in soft and hard water. Deployment durations in seawater exhibited a notable reduction compared to those in freshwater matrices. LSNZ-NP DGT excelling in oxyanion determination, while LSNT-NP DGT showcased superior efficacy in phosphorus quantification. Field deployments in rivers and sea affirmed the robustness of LSNZ-NP DGT, evidencing prolonged deployment capabilities for various elements, such as Mo, Se, As, Sb, and P, spanning 7–28 days. Assessment of pollution levels across four sampling sites revealed heightened concentrations of most elements in marine waters relative to riverine environments, except for phosphorus. Notably, all assessed elements, except for phosphorus, conformed to Class I water quality standards. This study demonstrated the difference between the theoretical application time and actual application time for the first time. It raises new questions for the application of DGT in nature water bodies. The mechanization of the difference between the theoretical and actual application time should be studied in the future research. The measures to extend the application time should be studied too.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Advanced Research
·
2018
·
IF 4.327
Nan You,Ji-Yu Li,Hong-Tao Fan,Hua Shen
Nitrophenols (such as o-nitrophenol (ONP), p-nitrophenol (PNP), and 2,4-dinitrophenol (DNP)) are priority environmental pollutants. Their toxicity is pH dependent, and these molecular species of nitrophenols exhibit higher toxicity than their anionic counterparts. Herein, for the first time, a method for the in situ measurement of nitrophenols in acidic industrial wastewater was developed using diffusive gradients in thin films (DGT) with lignocellulose hazelnut shell-derived activated carbons (HSACs) as the binding agents. Nylon membranes (0.1 μm rated) with diffusion coefficients of (2.02 ± 0.13) × 10 −6 cm 2 s −1 for ONP, (1.39 ± 0.09) × 10 −6 cm 2 s −1 for PNP and (1.20 ± 0.08) × 10 −6 cm 2 s −1 for DNP at 25 °C were used as the DGT diffusion layers. The accumulation of ONP, PNP, and DNP in DGT samplers based on the HSAC and nylon membranes (HSAC-DGT) agreed well with the theoretical curves predicted by the DGT equation in synthetic solutions with 200 μg L −1 nitrophenol. The uptake of the HSAC-DGT samplers for ONP, PNP, and DNP was found to be independent of the ionic strength of pNaNO 3 (−log [NaNO 3 ] (mol L −1 )) in the range of 0.7–3 and the pH range of 3–7 for ONP and PNP and 3–6 for DNP, which is beneficial for their accumulation. The matrices of the tested water samples exhibited no notable interference during nitrophenol analysis by the HSAC-DGT samplers. The results of field deployments in acidic industrial wastewater containing 268.3 ± 79.2 μg L −1 DNP were satisfactorily accurate, thus demonstrating that the HSAC-DGT samplers are good candidates for use in the in situ measurement of nitrophenols in acidic aqueous solutions.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
·
2025
·
IF 7.3
Chao Zhang,Xing-Yue Li,Dong-Xing Guan,Jia-Lu Gao,Qiong Yang,Xiao-Lei Chen,Lena Q. Ma
Cadmium (Cd) contamination in paddy soils threatens global food safety. While manganese (Mn)-based materials show promise in reducing soil Cd bioavailability, their efficacy requires further evaluation. Traditional ex situ sampling methods often overlook metal desorption kinetics and rhizosphere biochemical heterogeneity, potentially misinterpreting Mn's regulatory influence on Cd dynamics. This study employed in situ monitoring tools, including diffusive gradients in thin-films (DGT) measurements, DIFS (DGT-induced fluxes in soils) modeling, and high-resolution DGT and planar optode (PO) imaging, to assess the impact of two Mn oxides (MnO 2 and Mn 2 O 3 ) on Cd bioavailability in rice rhizosphere. Application of MnO 2 and Mn 2 O 3 reduced bioavailable Cd by 28.9 % and 15.3 %, respectively, attributed to elevated soil Mn and Fe levels fostering Cd immobilization. DGT-DIFS results revealed that Mn oxide application prolonged Cd replenishment time and reduced its desorption rate from soil solids. PO imaging identified pH heterogeneity in rice rhizosphere, confirming that Mn oxides mediated Cd bioavailability reduction by increasing pH. High-resolution DGT imaging revealed distinct spatial distribution patterns of Cd, Mn, and Fe fluxes, demonstrating Mn's inhibitory effects on Cd bioavailability. These findings highlight the potential of Mn oxides to mitigate Cd uptake by rice, offering a promising strategy for managing Cd-contaminated soils.
研究领域:
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 18
·10305-10311
·
IF 3.269
Tianxing Wu,Guozhong Wang,Yunxia Zhang,Mingguang Kong,Huijun Zhao
A diffusive gradients in thin films technique (DGT) device using thiol-modified carbon nanoparticle (SH-CNP) suspension as the liquid binding phase and cellulose acetate membrane as the diffusive layer was evaluated for determination of Hg2+ in water. Laboratory DGT validation experiments gave linear mass uptake over time (R2 ≥ 0.99) for Hg2+ in solutions of different concentrations. The effect of pH, ionic strength and potential interfering ions on Hg2+ binding with DGT devices was investigated. The results showed that the gathering amount of SH-CNPs-DGT for Hg2+ reached the maximum when the pH of solution was close to neutral and the ionic strength of solution and co-existing potential interfering ions such as Cd2+, Cr3+, Cu2+ and Pb2+ had no significant effect on gathering of SH-CNPs-DGT for Hg2+. Finally, validation of the SH-CNPs-DGT devices was undertaken for Hg2+ in spiked local water systems (Dongpu Reservoir and Nanfei River). For in situ measurements in Nanfei River water, the average labile Hg concentrations were 0.091 ± 0.009, 0.053 ± 0.003, and 0.071 ± 0.006 μg L−1 for three, six and seven days, respectively, which were lower than the value obtained by using ICP-MS, as DGT only measures ionic mercury and labile mercury species but direct measurement measures total mercury including inert organic species and large colloids.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Environmental Chemistry
·
2018
·Vol. 15
·期 4
·205-214
·
IF 2.923
Hui Yao,Nan You,Hong-Guang Cao,Li-Xia Kang,Jin-Bao Wu,Yu-Jie Zhao,Hong-Tao Fan,Yan-Li Yi
Environmental context Low 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. Calcium 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.
研究领域:
环境科学
·
农业科学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Si-Si Liu,Yu-Wei Jia,Xiao-Yuan Guo,Jian-Liang Zhao,Yue Gao,Andy J. Sweetman,Guang-Guo Ying,Li Xu,Chen Tu,Chang-Er Chen
Organic chemicals associated with microplastics (MPs) can be released and thus pose potential risks during weathering processes. However, the thermodynamics and kinetics of their release processes still need to be better understood. Herein, the adsorption and desorption kinetics of triclosan on polystyrene (PS) and polyvinyl chloride (PVC) were investigated by using both batch experiments and diffusive gradients in thin-films (DGT) technique. The pseudo-second-order model fitted the data best, implying that both intraparticle diffusion and external liquid film diffusion influence the adsorption and desorption processes. DGT continuously accumulated triclosan from MP suspensions but slower than theoretical values, indicating some restrictions to desorption. The DGT-induced fluxes in Soils/Sediment (DIFS) model, employed to interpret DGT data, gave distribution coefficients for labile species ( K dl ) of 5000 mL g −1 (PS) and 1000 mL g −1 (PVC) and the corresponding response times ( T c ) were 10 s and 1000 s, respectively. Higher K dl but smaller T c for PS than PVC showed that more triclosan adsorbed on PS could be rapidly released, while there were some kinetic limitations for triclosan on PVC. A novel finding was that pH and ionic strength individually and interactively affected the supply of triclosan to DGT. This is the first study to quantify interactions of organics with MPs by using DGT, aiding our understanding of MPs' adsorption/desorption behavior in the aquatic environment.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2024
·Vol. 16
·期 46
·7955-7964
·
IF 2.7
Si-si Liu,Shi-bao Chen,Yu-bo Yue,Xiao-hao Li,Chi Zhang,Guang-Guo Ying,Chang-Er Chen
Due to their wide applications, occurrence and “PFAS-like” environmental behaviors, ionic liquids (ILs) represent a new challenge for the environmental monitoring community, who require robust analytical methods that can determine accurately and efficiently their environmentally relevant concentrations. A new passive sampling method based on the diffusive gradients in thin films (DGT) technique was developed for the measurement of imidazole-based ILs in waters using a mixed-mode cation exchange (MCX) resin as the adsorbent. The selected binding gel had a high binding capacity (>170 μg per disc) for ILs. Diffusion coefficients measured using a diffusion cell correlated well with alkyl chain lengths (r2 = 0.95) and retention times (r2 = 0.88), providing a simple and rapid prediction approach for other ILs. The assembled MCX-DGT sampler exhibited a linear accumulation for at least 120 h. MCX-DGT also showed good performance under typical freshwater conditions (pH 5–8, ionic strength 0.001–0.01 M, and humic acid 0–5 mg L−1), while still being problematic for aquatic conditions with higher ionic strength (>0.1 M) or DOM (>10 mg L−1). Laboratory deployment (for up to 3 days) in spiked natural freshwater (SNW) resulted in linear mass uptakes for the short-chain ILs (C2–C8), and their DGT-measured concentrations agreed well with solution concentrations. However, MCX-DGT significantly overestimated the concentrations of the long-chain ILs (C10–C12) when deployed in SNW for one day or more, which is attributed to the strong competitive adsorption of the long-chain ILs by natural organic matter. In situ field evaluation along with grab sampling found no target ILs in a wastewater treatment plant and its receiving river, implying that these new chemicals might not be widely used in South China now. This is the first report on the DGT technique for ILs and might provide an effective tool for monitoring short chain length ILs in the aquatic environment in the near future.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2018
·
IF 6.653
Xinyao Shi,Wen Fang,Ni Tang,Paul N. Williams,Xuan Hu,Zhaodong Liu,Daixia Yin,Lena Q. Ma,Jun Luo
The speciation of selenium (Se) controls its fate and behavior, determining both its biological and environmental activities. However, in situ monitoring of SeIV presents a significant challenge due to its sensitivity to redox change. A novel diffusive gradients in thin films (DGT) technique containing mercapto-, amino-bifunctionalized SBA15 mesoporous silica nanoparticles was developed and evaluated in a series of laboratory and field deployment tests. The SBA-DGT exhibited a linear accumulation of SeIV (r2 > 0.997) over a 72 h deployment, with negligible accumulation of SeVI(<5%). Consistent prediction of SeIV occurred within ionic strength and pH ranges of 0.1–200 mmol L–1 and 3.6–8, respectively. Limits of detection of the SBA-DGT were 0.03 μg SeIV L–1, which is suitable for natural waters. Moreover, the properties of the bifunctionalized SBA15 enable it to be fabricated within ultrathin (0.05 mm) gel layers for use in conjunction with O2 planar optode imaging. This new sandwich sensor technology with SBA-DGT was validated by mapping the two-dimensional distribution of SeIV and oxygen simultaneously in rice rhizospheres. This study shows that SBA-DGT provides a selective measurement of SeIV in situ, demonstrating its potential for both environmental monitoring and as a research tool for improving our understanding of Se biogeochemical processes.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYST
·
2018
·Vol. 143
·期 22
·5568-5577
·
IF 3.864
Nan You,Zhong-Ming Feng,Yun Wang,Hong-Tao Fan,Ting Sun
A reliable method for the determination of dissolved Cu2+ and Pb2+ species in water via a diffusive gradient in thin films (DGT) device using water-soluble carbon nanodots (CD) as the binding agent was developed (CD-DGT). The uptake of dissolved Cu2+ and Pb2+ species by CD-DGT increased linearly with a deployment time of over 120 h, while the uptake of Ca2+, Mg2+, Cd2+, Zn2+, Ni2+, and Co2+ by CD-DGT has no significant linear accumulation during the same deployment time. The concentrations of the dissolved Cu2+ and Pb2+ species measured using CD-DGT are in good agreement with the element concentrations spiked directly in a tested synthesis solution. The performance of CD-DGT for the determination of dissolved Cu2+ and Pb2+ species is found to be independent of ionic strength in the range of 0.001–0.05 mol L−1 and in the pH range from 5 to 8. The presence of fulvic acid and tannic acid has no significant influence on the uptake of dissolved Cu2+ and Pb2+ species by CD-DGT under the tested conditions. In different water samples, good agreement was observed between the dissolved Cu2+ and Pb2+ concentrations measured by CD-DGT, and diffusive equilibration in the thin film devices was found. Based on the results obtained, CD-DGT enables the selective and quantitative determination of dissolved Cu2+ and Pb2+ species in water.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
Environmental Science-Advances
·
2023
·Vol. 2
·期 6
·837-847
·
IF 0
Hussain Ijaz,Jin-Xin Zi,Si-Si Liu,Qi-Si Cai,Sheng-Ming Cheng,Zong-Xi Zhao,Guang-Guo Ying,Andy J. Sweetman,Chang-Er Chen
The extensive use of artificial sweeteners (ASs) has raised concerns regarding their presence, fate, and detrimental effects in water resources. It is thus of great interest for researchers and regulators to acquire a sensitive, robust, and practical sampling technique for monitoring ASs. In the present study, an effective and established passive sampling method based on the diffusive gradients in thin films (DGT) technique was proposed to measure ASs in water. A mixed binding gel of WAX-XDA1 (3 : 1, w/w) was used for the first time in DGT. The selected mixed binding gel exhibited strong and rapid adsorption of ASs and its total binding capacity was over 20.6 μg per disc. 1% (v/v) ammonium hydroxide-methanol was demonstrated to be an excellent elution solvent for ASs with the elution efficiencies being 80.2–104.9%. The linear accumulation of ASs by WAX-XDA1-DGT matched well with the theoretical values, indicating that the current configuration performs in accordance with the DGT principle. The assembled WAX-XDA1-DGT sampler possessed a good tolerance to a wide range of pH (4–8), ion strength (0–0.5 M), and dissolved organic matter (0–10 mg L−1). In wastewater, comparable or lower DGT-measured concentrations for the ASs were observed compared to the spot sampling results. To the best of our knowledge, no studies have yet been conducted to in situ monitor ASs by using the DGT-based method. This study demonstrates the robustness and reliability of WAX-XDA1-DGT for measuring ASs under a wide range of freshwater circumstances in aquatic environments.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
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