ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2022
·
IF 7.129
Shengliang Zhao,Xuandi Lai,Feiyan Liu,Liqiong Chen
Hexavalent chromium (Cr(VI)) determination is of great importance to the public health because of its extensive sources and high toxicity. However, interference from non-target ions and complex matrix remains challenges for Cr(VI) detection. In this work, we constructed a novel sensing system for high selectivity detection of Cr(VI), which is composed of strong emitting carbon dots (CE-CDs) and a specific masking agent. The detection conditions, anti-interference capability and the sensing and masking mechanisms of CE-CDs-based sensing method were systematically investigated. The results revealed that the optimal detection conditions included pH 4–10, reaction time 180 s and CE-CDs concentration 18 mg/L. Under optimal conditions, the linear range of the method was up to 500 µm, and the detection limit was as low as 23 nM. In addition, the interference of Hg(II) can be accurately eliminated by using DMPS, an effective masking agent. During the sensing process, inner filter effect and ion-molecular interaction between Cr(VI) and CE-CDs accounted for the fluorescence quenching mechanism, while the efficient masking was attributed to the strong coordination interaction between Hg(II) and DMPS. Most notably, this method had broad applicability, even for the trace detection of Cr(VI) in colored leather with complex matrix. These findings indicate that this approach is expected to open up new avenues for Cr(VI) detection.
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 Environmental Chemical Engineering
·
2023
·
IF 7.7
Lanlan He,Xueyu Wang,Qiuju Li,Xiao Xiao,Fengfeng Li,Fangxiang Luo,Qingjiang Pan,Songdong Ding
Two novel water-soluble aromatic bisdiglycolamides (BisDGAs) of SO 3 -TEX( m )-BisDGA (sodium bis((2-(2-(diethylamino)− 2-oxoethoxy)acetamido)methyl)benzenesulfonate) and SO 3 -TEX( p )-BisDGA (sodium 2,5-bis((2-(2-(diethylamino)− 2-oxoethoxy)acetamido)methyl)benzenesulfonate) were synthesized and used as masking agents for the selective extraction and separation of Am 3+ over Eu 3+ in HNO 3 solutions by N,N,N′,N′,N′′,N′′ -hexaoctylnitrilotriacetamide (NTAamide( n -Oct)) in n -dodecane. Their influences on the separation effect of Am 3+ over Eu 3+ were investigated and compared with that of a water-soluble aliphatic bisdiglycolamide of N,N,N′′′,N′′′ -tetraethyl- N′,N′′ -ethidene bisdiglycolamide (TEE-BisDGA) reported by our previous work. SO 3 -TEX( m )-BisDGA and SO 3 -TEX( p )-BisDGA exhibit significantly better masking effects than TEE-BisDGA. The masking selectivity for Eu 3+ over Am 3+ follows the order of SO 3 -TEX( m )-BisDGA > SO 3 -TEX( p )-BisDGA > TEE-BisDGA. During the extraction process, the three BisDGA masking agents form the 1:2 complexes, while the NTAamide ( n -Oct) extractant forms the 1:1 complexes with Am 3+ and Eu 3+ . Meanwhile, the conditional stability constants (log β ) for the three masking agents with Eu 3+ were calculated using the least squares method, which are also in line with those obtained from fluorescence spectrometry (FS). By means of FS, time-resolved laser-induced fluorescence spectrometry (TRLFS), Fourier Transform infrared spectrometry (FT-IR), conductivity, and electrospray ionization mass spectrometry (ESI-MS) analyses, the composition of the complex of Eu 3+ with water-soluble BisDGAs (L) was determined to be [Eu(NO 3 ) 2 (H 2 O)∙2L](NO 3 ). Furthermore, a batch simulation of multistage countercurrent extraction with 12-stage extraction, 4-stage scrubbing and 8-stage stripping was carried out and demonstrates a highly efficient separation of Am 3+ over Lns 3+ with the recovery rates above 99.9 % for all metal ions in the simulated feed solution, and with the decontamination factors more than 500 between Am 3+ and most of the lanthanide ions.
研究领域:
化学
·
核化学与放射化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2021
·Vol. 23
·期 11
·4044-4050
·
IF 10.182
Zhicheng Jiang,Shuguang Xu,Wei Ding,Mi Gao,Jiajun Fan,Changwei Hu,Bi Shi,James H. Clark
An oligosaccharide-based masking agent suitable for chrome-free metal tanning was produced from cellulose via a stepwise degradation and oxidation process. Firstly, an AlCl3-NaCl-H2O/γ-valerolactone (GVL) biphasic solvent system was established for cellulose conversion (87.6%), which allowed in situ separation of the oligosaccharides and valuable small molecules into the two phases. Then, a H2O2 oxidation process enabled further degradation of the oligosaccharides and introduced –CHO/–COOH groups. This process strengthened the surface charge of the oligosaccharides, enhancing their coordination ability with metal ions. The post-oxidized fraction, together with added Zr species, exhibited satisfactory tanning performance, with a shrinkage temperature of 85.2 °C for the tanned leather. Al/Zr species could spontaneously coordinate with O atoms of OC(2) in the carboxylic group of post-oxidized oligosaccharides, which promoted the penetration of Al/Zr species into the leather matrix for efficient crosslinking reactions.
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
TALANTA
·
2023
·
IF 6.1
Haimin Li,Xinyu Huang,Fengxian Zhang,Xueting Luo,Wenqian Yu,Cao Li,Bingbing Jiang,Zhenpeng Qiu,Ziqiang Xu
Due to the worldwide ecological and environmental issues induced by heavy metal pollution, including zinc and manganese, the ratio-metric discrimination of Zn 2+ and Mn 2+ based on CDs is urgently required. In this work, reduced CDs (re-CDs) with the intrinsic dual emissive peaks are obtained, and specific discrimination of Zn 2+ and Mn 2+ is realized by re-CDs with ratio-metric mode. With the addition of Zn 2+ , the fluorescent (FL) intensity at 650 nm increases obviously, while that at 680 nm progressively decreases. However, the presence of Mn 2+ would induce the quenching of FL intensity at 680 nm while that at 650 nm remains constant. Then the Zn 2+ and Mn 2+ can be separately determined with the ratio of FL intensity at 650 nm to that at 680 mm ( F 650 / F 680 ). Under optimal conditions, the limit of detection (LOD) of Zn 2+ is determined to be 9.09 nmol/L, and that for Mn 2+ is estimated to be 0.93 nmol/L, which is much lower than previously reported work and standard level of Zn 2+ and Mn 2+ permitted in drinking water by WHO. Moreover, the specific recognition of Mn 2+ and Zn 2+ can be realized via the addition of different masking agents (ethylenediamine for Zn 2+ and triethanolamine for Mn 2+ ). Furthermore, our results reveal that the structural changes from –NH–C O to –N C–OH induced by Zn 2+ contribute to the shift of FL peak from 680 to 650 nm while both static and dynamic quenching processes are involved in the detection of Mn 2+ . The ratio-metric probe was successfully applied to Zn 2+ and Mn 2+ determination in human serum samples and Sandy Lake water.
研究领域:
环境科学
·
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）