MINERALS ENGINEERING
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2018
·
IF 2.707
Baijun Yan,Daya Wang,Liushun Wu,Yuanchi Dong
Stone coal, a kind of important vanadium-bearing resources in China, accounts for about 87% of the domestic reserves of vanadium. But the currently developed techniques to extract vanadium from stone coal are all confronted with environmental problems. For example, large quantities of caustic or greenhouse gases discharged in the oxidizing roast process, enormous consumptions of acid or alkali in the leaching step and massive tailings containing toxic V 5+ ions. With a view to solve those problems, an innovative process for pre-concentration of vanadium from stone coal was designed and confirmed on a laboratory scale. The distinct features of this design are as follows. Firstly, the environment-friendly Fe 2 O 3 is selected as a capturer of vanadium. Secondly, the natural reducing property of stone coal is utilized to promote the formation of magnetic V-rich phase, Fe 2 VO 4 . Thirdly, a high-grade vanadium concentrate is obtained by magnetic separation method. The practicability of this design was confirmed using industrial stone coal on a laboratory scale. When 10 mass% Fe 2 O 3 relative to stone coal was added and roasted at 1200 °C for 3 h, a high-grade concentrate containing vanadium higher than 14 mass% was obtained, and more than 91% of the total vanadium in stone coal was recovered.
研究领域:
冶金学
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2022
·
IF 5.895
Chang Liu,Yuye Li,Ting Chen,Shuyun Meng,Dong Liu,Daming Dong,Tianyan You
Efficient preconcentration is critical for sensitive and selective electrochemical detection of metal ions, but rapid specific enrichment with depressed absorption of interfering ions at the electrode is challenging. Here, we proposed an electric field-induced specific preconcentration to boost the analytical performance of DNA-based electrochemical sensors for Hg2+ detection. As for such preconcentration, a positive external electric field was first used to enrich Hg2+ at an electrode assembled with T-rich DNA, thus boosting T–Hg2+–T recognitions. The following applied inverse electric field strips the nonspecifically absorbed Hg2+ and other interfering ions, thus depressing matrix interferences via self-cleaning. Based on this principle, we designed a portable device to realize programmable control of electric fields; a T–Hg2+–T recognition-based electrochemical sensor was thus fabricated as a model platform to assess the feasibility of electric field-induced preconcentration. The experimental results revealed that such a strategy decreased the time of T–Hg2+–T-based recognition from 60 to 20 min and led to detection with better reproducibility by depressing the influence of free Hg2+ as well as interfering ions. This strategy offered Hg2+ detection limits of 0.01 pM─three-fold better than that without preconcentration─within 22 min. The proposed preconcentration strategy offers a new way to enhance the analytical performance of sensing at the solid–liquid interface.
研究领域:
分析化学
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环境科学
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生物传感
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2022
·
IF 5.304
Lanlan Li,Qirui Huang,Jing Xiao,Jiamin Feng,Shu Zhang,Hong Luo,Zhirong Zou,Xiaoli Xiong
Fe 3 O 4 was served as an adsorbent and photocatalyst simultaneously in this work, Bi(III) was preconcentrated by Fe 3 O 4 before its photochemical vapor generation-atomic fluorescence spectrometry (PVG-AFS) determination. The experimental conditions including the concentration of formic and acetic acid mixed solution, ultraviolet (UV) irradiation time, the concentration of Fe 3 O 4 and the interferences from the common co-existing ions were explored. The AFS intensity was enhanced slightly by the mixed acid solution (30% (v/v) acetic acid + 5% (v/v) formic acid), while a significant enhancement was observed by using Fe 3 O 4 as photocatalyst with the presence of mixed acid solution, 13-fold enhancement was obtained. The potential enhanced mechanism of Fe 3 O 4 was also discussed here. Fe 3 O 4 was decomposed in the mixed acid solution, Fe 3+ was generated and further served as a sensitizer for improving Bi(III) efficiency. Under the optimized conditions, the limit of detection (LOD) of the proposed PVG-AFS system without or with preconcentration (sample of 5 mL) were 0.44 ng/mL and 0.07 ng/mL, respectively. This PVG-AFS system was successfully applied to the determination of four water samples and their spiked samples, with good recoveries ranging from 94% to 104%, demonstrating a good accuracy and applicability.
研究领域:
分析化学
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环境科学
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产品关联
DOI
高影响因子
GEOSTANDARDS AND GEOANALYTICAL RESEARCH
·
2024
·
IF 2.7
Qiuyun Guan,Xudong Guo,Yali Sun,Xiaoming Liu,Shouqian Zhao
A simple method was developed for the determination of REEs, Zr, Hf, Th and U in ultramafic rocks by inductively coupled plasma-mass spectrometry with a combination of RE and UTEVA extraction resins for their separation and pre-concentration. Ultramafic rocks were digested with HNO 3 -HF-HClO 4 and finally turned into 11 mol l −1 HCl solutions together with H 3 BO 3 to remove insoluble fluorides. The removal of matrix elements was achieved during the loading procedure. Following this, REEs on RE resin, and Zr, Hf, Th and U on UTEVA resin were eluted with 10 ml of 0.24 mol l −1 HCl, with recoveries better than 94.4%. This method was validated using reference materials JP-1, DTS-2B, OKUM, UB-N, MUH-1 and DZΣ-2, and the measurement results for target analytes were comparable to literature values, indicating its applicability to the determination of REEs, Zr, Hf, Th and U at ultra-trace level in ultramafic rocks.
研究领域:
地球化学
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分析化学
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产品关联
DOI
高影响因子
ENVIRONMENTAL MONITORING AND ASSESSMENT
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2012
·Vol. 185
·期 1
·39-44
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IF 1.4
Jiao Fang,Gao Hong-Wen
An on-site solid-phase extraction, consisting of the sorption, the separation and the elution function units, was designed for in situ preconcentration of heavy metals ions. The D401 resin powder was employed as sorbent to capture Pb 2+ , Cu 2+ , Zn 2+ , Cd 2+ , Co 2+ , and Ni 2+ , and then they desorbed with 2 mol/L nitric acid as eluent. Under the optimized conditions, these heavy metals ions in West Lake, Taihu Lake, and Yangtze River of China were captured and then determined by ICP-OES with the recovery of 92.5% to 111.5%. The on-site solid-phase extraction achieved a quick preconcentration of heavy metals to avoid the transport and storage of a large volume water sample. It is suitable for in situ monitoring of water quality in mountains, tablelands or other remote areas.
研究领域:
环境科学
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分析化学
✓ 已验证
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2023
·
IF 6.2
Qing Yang,Chenghui Li,Jing Hu,Xiandeng Hou
Background Selenium is an indispensable microelement for humans and food is the main source of selenium intake. As one of the best techniques for the determination of selenium, inductive coupling plasma-mass spectrometry (ICP-MS) features some unique advantages, such as wide linear range and high sensitivity. Nevertheless, it still remains a challenge to achieve the accurate and high sensitivity determination of ultra-trace selenium in food samples by ICP-MS owning to the high first ionization energy of selenium and interferences from sample matrices as well as isobaric interferences. Results In this work, UiO-66-NH 2 (metal organic framework, MOF) was fast synthesized by microwave method and employed for the preconcentration of ultra-trace selenium with an adsorption efficiency of nearly 100 %. The selenium-adsorbed MOF was collected by filtration, and then simply converted to slurry for in situ hydride generation (HG) for sensitive detection of selenium by ICP-MS. Various factors affecting the adsorption of selenium by the MOF (including pH, adsorption time, and amount of MOF) together with main parameters of hydride generation (including concentrations of HCl and NaBH 4 ) were carefully evaluated. Experimental results show that effective matrix separation can greatly reduce interference, with an excellent detection limit of 1 ng/L. The practicability and accuracy of this method were successfully confirmed by the determination of trace selenium in several food samples. Significance UiO-66-NH 2 (MOF) was used as an effective adsorbent for the preconcentration of selenium prior to direct slurry sampling HG-ICP-MS determination. Direct slurry sampling avoided additional elution procedures and was conducive to eliminating matrix and isobaric interferences. High sensitivity and interference-free determination were achieved for determination of ultra-trace Se in complex food samples.
研究领域:
分析化学
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环境科学
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食品安全
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2024
·
IF 4.9
Lin Chen,Guanyu Lan,Yan Xu,Xue Li,Xuefei Mao
Hydrogen-bonded organic framework (HOF) is a novel and ideal material for preconcentration of heavy metal in water by hydrogen bonding considering simple synthesis and low cost. In this work, magnetic HOF material (Fe 3 O 4 @HOF) was designed and synthesized under simple and mild conditions for preconcentration and detection of lead (Pb) and copper (Cu) in water. This Fe 3 O 4 @HOF exhibits maximum adsorption capacities for 579.81 mg/g Pb 2+ and 146.48 mg/g Cu 2+ , respectively, with an excellent selectivity (>95 % adsorption) for Pb 2+ and Cu 2+ in presence of other ions; as well, shows a favorable recycling performance (>95 % adsorption) after 10 adsorption–desorption cycles based on external magnetic adsorption. The mechanism results proved that the adsorption of Pb 2+ and Cu 2+ might be attributed to chemisorption, electrostatic interactions and ion exchange. Based on the glass fiber membrane filtration, Fe 3 O 4 @HOF can be utilized as enrichment material coupled with X-ray fluorescence spectrometer (XRF) for detection of Pb 2+ and Cu 2+ in water; the limits of detection (LODs) for Pb 2+ and Cu 2+ were 1.5 μg/L and 1.3 μg/L (from 100 mL water to 5 mg Fe 3 O 4 @HOF), respectively. This work presents a green, economical and eco-friendly novel material that can be easily prepared, separated and reused, demonstrating a promising potential for efficient preconcentration and accurate detection of heavy metals in water.
研究领域:
环境科学
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分析化学
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产品关联
DOI
高影响因子
Science China-Chemistry
·
2015
·Vol. 58
·期 10
·1593-1599
·
IF 1.695
He Yayun,Ding Longhua,Su Bin
Silica mesochannels (SMCs) vertically and regularly oriented to the surface of indium tin oxide (ITO) electrodes were prepared and utilized for preconcentration and detection of methylene blue (MB) in aqueous solution. The positively charged MB can be adsorbed to the SMCs by following the pseudo-first-order kinetic model. The negative value of Δ G =−34.73 kJ/mol derived from the Langmuir adsorption isotherm indicated the thermodynamic feasibility of the adsorption and the spontaneous nature of the process. Moreover, the adsorbed MB can undergo an electrochemical reaction on the ITO electrode at a suitable potential and the resulting electrical current can be utilized to quantify the MB in aqueous solution. A good analytical performance for MB with a linear range from 10 nmol/L to 1.0 μmol/L and a detection limit at the nmol/L level was obtained. We believe that such a platform consisting of SMCs perpendicularly tethered to the underlying electrode surface simultaneously allows enrichment and electrochemical detection and can be extended for the detection of various charged dyes, as well as many other charged species.
研究领域:
材料科学
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分析化学
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DOI
高影响因子
WATER SCIENCE AND TECHNOLOGY
·
2014
·Vol. 70
·期 12
·1913-1918
·
IF 1.212
Meng Lifen,Ning Jinyan,Yang Yaling
A sensitive and simple method for flame atomic absorption spectrometry determination of traces of cadmium and chromium(III) species in water samples after preconcentration by cloud point extraction has been developed. A novel complex agent of alizarin complexone with cadmium (Cd) and chromium (Cr(III)) was quantitatively extracted in surface primary alcohol ethoxylate-rich phase at 33 °C. The effects of experimental conditions including pH of sample solution, concentration of chelating agent and salt, equilibration temperature and time, and foreign ions were evaluated in order to enhance sensitivity of the method. Under optimal conditions, the low limit detections were 6.7 and 3.2 μg/L, and the enrichment factors were 24 and 20 for Cd and Cr(III), respectively. The relative standard deviations were 3.8 and 2.5% for Cd and Cr(II), respectively ( n = 11). The high recoveries of the spiked Cd and Cr(III) ions were obtained in the range of 90–116%. The proposed method has been successfully applied for the determination of Cd and Cr(III) in water samples.
研究领域:
分析化学
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环境监测
·
重金属检测
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水环境科学
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痕量元素分析
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DOI
高影响因子
MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 9
·3497-3504
·
IF 4.58
Zhou Shaoyan,Song Naizhong,Lv Xueju,Jia Qiong
The authors describe a hybrid of magnetic task-specific poly(ionic liquid) containing dual task-specific sites in an approach to both preconcentrate and quantify gold(III), palladium(II) and platinum(IV). The hybrid was obtained by successive alkaline coprecipitation, sol-gel, quaternization, elimination, anion exchange and polymerization. The material was characterized by scanning electron microscopy, transmission electron microscopy, FTIR spectroscopy, thermal gravimetric analysis, X-ray photoelectron spectrometry, X-ray diffractometry, and vibrating sample magnetometry. It was applied as an effective sorbent for magnetic solid-phase extraction of gold(III), palladium(II) and platinum(IV) ions. The effects of sample pH, amount of adsorbent, extraction time, eluent concentration and volume were optimized. Following elution with a thiourea/HCl solution, the ions were quantified by graphite furnace AAS. The calibration plot is linear in the 50 to 350 ng·L −1 gold(III) concentration range, in the 50 to 650 ng·L −1 palladium(II) concentration range, and in the 150 to 2100 ng L −1 platinum(IV), respectively. Other figures of merit for noble metals determination, respective, include (a) detection limits of at 19.7, 22.3 and 107.0 ng·L −1 , (b) enrichment factors of 197, 174 and 168; and (c) reproducibilities (expressed as relative standard deviations) of 2.1%, 1.4% and 1.5%. In our perception, the method excels by its high sensitivity and preconcentration capability. It was successfully applied to the determination of gold(III), palladium(II) and platinum(IV) in certified reference materials and (spiked) real samples.
An adsorbent assembling dual task-specific poly(ionic liquid) onto magnetic nanoparticles was used to preconcentrate noble metals. After experimental optimizations, the resulting magnetic hybrid material was applied to measure the concentration of noble metals in real samples.
研究领域:
分析化学
·
材料科学
·
环境科学
·
纳米技术
·
冶金化学
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2015
·Vol. 182
·期 7
·1337-1344
·
IF 3.741
Cui Yang,Liu Sheng,Wei Kaiju,Liu Yangzhong,Hu Zhangjun
We describe a method for magnetic solid phase extraction of trace-levels of Hg(II) ions by using Fe 3 O 4 nanoparticles (NPs) covered with a shell of silica and modified with the chelator N-(2-acetylaminoethyl)-N′-(3-triethoxysilylpropyl)thiourea. The new magnetic NPs enable rapid magnetic separation, thus leading to higher efficiency and accuracy. The extracted Hg(II) ions on the NPs were directly quantified using a mercury analyzer. Possible interferents are widely eliminated in this highly selective extraction process, and the NPs are not exerting an interfering effect either. The method has an enrichment factor of 100, and extraction recoveries are between 95 and 107 % when using 10 mg of the extracting NPs. The method works over a wide range of pH values and can be applied to even complex natural samples. The effects of pH value, extraction time, sample volume and adsorbent amount on the extraction efficiency were optimized. Under the optimal conditions, the detection limit is as low as 17 ng L −1 . The method was applied to the preconcentration and detection of Hg(II) in three natural water samples using the standard addition method.
A facile magnetic solid phase extraction using surface decorated nano-scale magnetic core-shell nanoparticles coupled with a direct mercury analyzer is proposed for trace-level mercury ions detection.
研究领域:
环境化学
·
分析化学
·
纳米材料科学
·
生物医学分析
·
重金属检测
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2011
·
IF 3.65
Xiaofang Shen,Yan Cui,Yuehong Pang,He Qian
1-Hydroxypyrene (1-OHP) is a ubiquitous metabolite of polycyclic aromatic hydrocarbons (PAHs) and has been widely used as a biomarker for evaluation of human exposure to PAHs. In this paper, an electrochemical sensor consisted of graphene oxide nanoribbon (GON)/octa(3-aminopropyl)octasilae quioxane octahydrochloride (OA-POSS) framework films (GON/OA-POSS) modified electrode for pre-concentrating and sensing of 1-OHP was described. The GON/OA-POSS composite films were prepared by hierarchically layer-by-layer assembly via electrostatic interactions. GON, which has higher electrical conductivity than that of graphene oxide, offers residual π-conjugated systems for adsorption of 1-OHP via π–π stacking interaction. Meanwhile, OA-POSS nanocages make the GON layers frameworked to enhance contacting between GON and 1-OHP. When 1-OHP was pre-concentrated on GON/OA-POSS frameworks modified electrode, the response signal and adsorption stability was enhanced significantly. Differential pulse voltammetry was used for direct determination of 1-OHP. The electrochemical sensor calibration curve had a range of 0.1–12.55 μM ( R = 0.995) with a detection limit of 0.04 μM. The results showed that the GON/OA-POSS framework films modified electrode established a new way for simple and sensitive analysis of 1-OHP.
研究领域:
环境科学
·
分析化学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）