SENSORS AND ACTUATORS B-CHEMICAL
·
2016
·
IF 4.758
Guo Chen,Xia Hao,Bang Lin Li,Hong Qun Luo,Nian Bing Li
In this work, a simple and reliable electrochemical method for the determination of cadmium using an antimony film modified sodium montmorillonite (NaMM) doped carbon paste electrode (Sb/NaMM-CPE) was described. Due to the strong cation exchange ability and adsorptive characteristics of NaMM and excellent electroanalytical performance of the antimony film, the new electrode significantly enhanced the sensitivity for detection of Cd(II) and exhibited superior performance in comparison with the bare carbon paste electrode, antimony film modified carbon paste electrode (Sb/CPE), and NaMM modified carbon paste electrode (NaMM-CPE). Some parameters such as the composition of the paste, pH of the measure solution, the Sb(III) concentration, deposition time, and deposition potential that influenced the response of cadmium were investigated and the procedure was optimized for cadmium determination. This electrode, combined with square-wave anodic stripping voltammetry, displayed excellent linear behavior in the examined concentration range of 4.0–150.0 μg L −1 Cd(II) ( R 2 = 0.998) with a detection limit of 0.25 μg L −1 . The Sb/NaMM-CPE was successfully applied to the determination of cadmium ion in tap water sample.
研究领域:
电化学
·
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
RUSSIAN JOURNAL OF GENERAL CHEMISTRY
·
2024
·Vol. 94
·期 1
·170-183
·
IF 0.9
Li T.,Fu X.,Wang Y.,Ouyang F.,Liu L.,Wen M.,Zha G.,Zhu L.
Abstract Celecoxib (CXB) is a nonsteroidal anti-inflammatory drug (NSAID). However, the application of CXB has been compromised by its poor aqueous solubility and low oral bioavailability. We developed a series of ternary solid dispersions (SDs) of CXB to increase its solubility. In this study, the polymers were screened to determine that they have the potential to increase the solubility of CXB in the solution. A hydrophilic polymer-hydroxypropyl methylcellulose (HPMC) and a surfactant Tween80 were employed as matrix respectively in the optimized formulations. Experimental data revealed that CXB was molecularly distributed within all dispersions in amorphous form by using Differential Scanning Calorimetry (DSC), Polarizing Light Microscopy (PLM), and X-ray powder diffraction (XRD). Fourier Transform Infrared Spectroscopy (FTIR) results showed that the characteristic peaks of CXB have shifted. Compared with pure CXB, the addition of excipients can reduce the contact angle, and improve the solubility of CXB. Ternary SDs were dissolved in PBS (pH 6.8) and formed drug-carrying nanoparticles. In vitro dissolution results indicated that the dissolution amount of HPMC-CXB 5 : 1 SD (32.08±1.56% for 120 min) was higher than pure CXB (3.09±0.29%). In particular, the greatest dissolution enhancement was obtained from the test of which the result was HPMC/Tween80-CXB 3 : 2 : 1 SD (44.12±2.01% for 120 min). This study showed that ternary SDs could be a promising strategy for improving CXB dissolution.
研究领域:
药剂学
·
药物化学
✓ 已验证
产品关联
DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2015
·Vol. 226
·期 5
·1-9
·
IF 1.554
Wang Qian,Liu Xiaoyan,Wang Chuanhua,Zhang Xinying,Li Hongbing,Chen Tingru,Hou Yunyun,Chen Xueping,Liang Xia
Four kinds of surfactants were used to increase accessibility of pyrene and cadmium (Cd) in simulated pyrene, Cd, and pyrene-Cd soils in this study. Tea saponin (TS) at 40 mg L −1 groups (exchangeable fraction of Cd and bioaccessible fraction of pyrene were 8.96 and 36.93 mg kg −1 ) showed more preferable potential application in improving solubilization capability than other surfactants. The morphology of Cd was transformed from Fe-Mn oxides (8.86 to 7.61 and 8.67 to 7.99 mg kg −1 in Cd and pyrene-Cd soil) and associated to carbonates fractions (4.46 to 4.36 and 4.28 to 4.36 mg kg −1 in Cd and pyrene-Cd soil) to exchangeable fraction with adding TS. These two morphological changes were important processes in the solubilization of Cd. The morphology of pyrene was transformed from associated fraction (72.15 to 61.95 and 71.02 to 63.48 mg kg −1 in pyrene and pyrene-Cd soil) to bioaccessible fraction (26.66 to 33.71 and 26.91 to 36.93 mg kg −1 in pyrene and pyrene-Cd soil) with adding TS. This morphological transformation was important in the improving of solubilization capacity of pyrene. In contrast, the solubilization of pyrene was promoted in the presence of Cd in pyrene-Cd soil (the bioaccessible fractions were 33.71 and 36.93 mg kg −1 in pyrene and pyrene-Cd soil), but the solubilization of Cd was hindered in the presence of pyrene (the exchangeable fractions of Cd were 8.86 and 8.67 mg kg −1 in Cd and pyrene-Cd soil). These findings will be beneficial for application of surfactants in soil remediation.
研究领域:
环境科学
·
土壤学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Yanjun Ou,Shuhua Ma,Xiaohui Wang,Hao Wu,Helong Hui,Yi Zhang
China produces over 50 % of global alumina , but its dependence on imported bauxite is as high as 65 %. Local bauxite in China is of low grade. During mining, high-grade ores were sold, while low-grade ores were left piled up on site. This practice not only occupied a large land area but also caused serious pollution. Additionally, kaolinite and diaspore are embedded in a complex and dispersed distribution on the micron scale. The physical separation and ore phase dissociation of these two (kaolinite and diaspore) are very difficult, thereby preventing the economical and efficient utilization of Chinese bauxite using existing mineral flotation and sintering technologies. Based on the analysis of the molecular structure of kaolinite , this study found a significant difference in the dissolution rates of kaolinite and diaspore in a low-alkali solution. This conclusion was drawn through a combination of kinetic analysis and experimental exploration. Therefore, a new chemical pre desilication method of diaspore bauxite rich in kaolinite was proposed. The experiment found that at temperature of 180 ℃ and Na 2 O concentration of 20 g/L, the solubility of kaolinite in a low alkali solution was 3.3 g/L. After 40 minutes of reaction, the maximum dissolution of kaolinite reached 4.2 g/L. Under the same conditions, the solubility of diaspore was 0.064 g/L. The results of kinetic study showed that the activation energy of pure kaolinite dissolution reaction was 26.77 kJ/mol, which belongs to diffusion control. Conversely, the dissolution reaction activation energy of pure diaspore was 84.30 kJ/mol, which belongs to chemical reaction control . In low alkali systems, there was a significant difference in dissolution rate between the two. By optimizing the process conditions, the optimal process conditions were found. Under the optimal conditions, the aluminum silicon ratio increased from 3.22, 2.91, and 2.68–7.92, 8.42, and 8.17, respectively, by processing three types of low-grade bauxite with different particle sizes. It is noteworthy that this method can achieve a significant increase in bauxite A/S only requiring two simple processing steps: alkali dissolution and liquid-solid separation. This study not only fills the research and application gap of low alkali solutions in the field of bauxite beneficiation, but also helps to support the green and sustainable development of the world's alumina industry.
研究领域:
矿物加工工程
·
材料科学与工程
✓ 已验证
产品关联
DOI
高影响因子
Water
·
2022
·Vol. 14
·期 14
·2248
·
IF 3.53
Guowei Pang,Min Ji,Zhuoran Li,Zhengwu Yang,Xiaojie Qiu,Yingxin Zhao
In this work, an efficient cage-core peroxymonosulfate (PMS) catalyst was synthesized by applying an electrospinning–calcination process to the cobalt–zeolitic imidazole framework (ZIF-67) crystals for the catalytic degradation of dimethyl phthalate (DMP). The morphology and surface properties of the synthesized materials (ZIF-67, Z600 and ZP400/600/800) were well characterized. ZP600 showed great performance for the catalytic degradation of DMP in the initial pH range of 7.5–10.5. The removal rate of DMP could reach 90.4% in 60 min under optimum dosages of reagents (catalyst = 0.1 g/L, PMS = 0.5 mM, DMP = 6 ppm), and the mineralization degree of contaminant could reach 65%. By quenching experiments, it was determined that sulfate radical (SO4−·) and hydroxyl radical (·OH) dominated the degradation process. Moreover, due to the good magnetism, ZP600 could be easily separated from liquid and showed great reusability in five-cycle reaction experiments. Surprisingly, with the cover of cage-like polyacrylonitrile (PAN) fibers, the cobalt leaching amount of ZP600 decreased by about 87%. This study would expand the application of the electrospinning process in the development of functional materials for water purification.Keywords:elctrospinning;ZIF-67;peroxymonosulfate;cobalt leaching control
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Qi Ni,Congcong Ding,Fuxin Liu,Fen Luo,Xiaoyan Shu,Yulu Fu,Xirui Lu
Multi-component high-entropy pyrochlore (HEP) offers several advantages compared to single-component pyrochlore in solidifying radioactive waste , including the ability to solubilize multiple types of waste and lower leaching rates (LRs) of radionuclides . In this study, we successfully synthesized HEP (Y 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Gd 0.2 ) 2 Zr 2 O 7 and immobilized Ce, a simulated nuclide of Pu at 1500 °C for 48 h using a free occupied design approach. The Raman, XRD , and Rietveld refinement results showed that the immobilization limit for Ce fell between 20 wt .% and 30 wt .%. Notably, the ordered pyrochlore phase gradually transformed into the defective fluorite phase with an increase in Ce content. Moreover, the leaching tests demonstrated the excellent stability of the matrix, with the normalized LR for Ce reaching 10 −7 g·m −2 ·L −1 after 42 days at 90 °C. These findings collectively suggest that HEP (Y 0.2 Nd 0.2 Sm 0.2 Eu 0.2 Gd 0.2 ) 2 Zr 2 O 7 holds promise as a substrate for immobilizing radioactive waste in the future.
研究领域:
材料科学
·
核能工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Chaolei Yuan,Fangbai Li,Wenhua Cao,Zi Yang,Min Hu,Weimin Sun
We successfully accounted for the dynamics of cadmium (Cd) solubility in paddy soil that contained a realistically low total Cd concentration (0.36 mg kg −1 ) after submergence and redrying by monitoring multiple chemical and microbial soil properties. The addition of rice straw promoted greater microbial iron reduction and induced a greater increase in soil pH after submergence, compared to the control and treatments with added gypsum or hematite. Consequently, dissolved Cd decreased to under the detection limit in one week in the straw-amended treatment but remained high even after eight weeks in the other three treatments. The Cd solubility strongly correlated with soil pH and was unlikely to decrease due to Cd precipitation in secondary iron minerals. After five weeks of redrying, the dissolved Cd content was still the lowest, and the putative iron-reducing bacteria Geobacter remained the most abundant in the straw-amended soil. The results suggest that the addition of organic matter can efficiently immobilize soil Cd at an environmentally realistic concentration by stimulating the microbial reduction of native oxidized soil components after submergence, while adding extra iron oxide or sulfate alone is not effective because it does not eliminate the limitation imposed by electron donors on microbial reduction.
研究领域:
土壤科学
·
环境微生物学
✓ 已验证
DOI
高影响因子
FLAVOUR AND FRAGRANCE JOURNAL
·
2016
·Vol. 32
·期 2
·102-111
·
IF 1.693
Zujin Yang,Liyun Huang,Xingdong Yao,Hongbing Ji
Estragole (ES) has multiple biological activities and is widely used in food preservation. However, the applications of ES are limited because of its low water solubility and high volatility nature. In this paper, the β-cyclodextrin (β-CD) inclusion complex of ES was prepared by a co-precipitation method with the aim of enhancing its thermal stability and realize its controlled release. Solubility experiments were performed to evaluate the effect of β-CD on ES aqueous solubility. Release experiments of ES from its inclusion complexes were carried out at different temperatures with a relative humidity (RH) and Avrami's equation was used to analyse the release data. The antimicrobial activity of the free and included ES was also examined. The results indicated that the host–guest interactions played a crucial role in enhancing the properties of ES. The inclusion complex was investigated using physico-chemical techniques such as Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA and DSC), 1H and 2D nuclear magnetic resonance (NMR). The inclusion processes between β-CD and ES were simulated using the semi-empirical PM3 and ONIOM [B3LYP/6-31g(d):PM3] methods. Copyright © 2016 John Wiley & Sons, Ltd.
研究领域:
食品科学
·
药物化学
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
·
2018
·
IF 2.297
Wenhao Xu,Ying Sun,Liping Du,Yulia S. Chistyachenko,Alexandr V. Dushkin,Weike Su
Valsartan has been used for the treatment of hypertension disease. However, the oral bioavailability of valsartan has been reported to be only ∼23%, accompanied with high permeability and poor aqueous solubility. The object of this research was to prepare solid dispersions of valsartan with an inorganic (CaCO 3 ) and organic base ( N -methyl- d -glucamine) in an effort to increase the aqueous solubility and dissolution rate of the drug. The as-prepared solid dispersions of valsartan were prepared in an environmentally friendly manner using CaCO 3 and MG and a roll mill. The physicochemical properties were studied in the solid state using DSC , PXRD and IR. Furthermore, the solubility of valsartan increased 46-fold in solid dispersion with CaCO 3 and 9-fold in solid dispersion with MG. More than 95% of valsartan in solid dispersions was found to be released in simulated intestinal fluid, whereas only 35% was found to be released using pure valsartan within the same time interval. Storage tests showed that the as-prepared solid dispersions were equally stable compared to pure valsartan at 40 °C. Potentially, the synthesized solid dispersions of valsartan with enhanced solubility and dissolution rates may represent promising formulations for improving the overall oral bioavailability of the drug in clinical applications.
研究领域:
药剂学
·
药物化学
✓ 已验证
DOI
高影响因子
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
·
2022
·
IF 5.062
Guan-Lan Huang,Ling Yang,Bo-Ying Ren,Xin-Yue Lv,Ling-Yi Song,Xia-Lin Dai,Jia-Mei Chen
Vemurafenib (VEM) is a first-line drug for the treatment of metastatic melanoma with BRAF V600 mutation, which was developed in the form of amorphous solid dispersion to overcome the defects of poor aqueous solubility and oral absorption. However, the oral dose of VEM is still very high; besides, the poor stability of amorphous form may increase the risks in drug effectiveness and safety. Herein, we attempted to provide a solution to these issues based on cocrystallization strategy. Three cocrystalline forms involving VEM and D / L / dl -camphorsulfonic acid with stoichiometric ratio of 1:1 were synthesized and characterized by powder X-ray diffraction analysis, 1 H nuclear magnetic resonance, thermal analyses and Fourier transform infrared spectroscopy . The in vitro evaluations show that all of the cocrystalline forms demonstrate improved hygroscopicity and stability compared to amorphous VEM; especially, the cocrystalline form with dl -camphorsulfonic acid exhibits much better tabletability and apparent solubility than all of other forms. Pharmacokinetic tests reveal that all the cocrystallized products show significantly enhanced C max and AUC 0-t values compared to the amorphous form. Therefore, the newly discovered cocrystalline forms of VEM are expected to overcome the issues of poor solubility and oral absorption and provide great potential for the development of improved preparations of the drug.
研究领域:
药物化学
·
药剂学
·
肿瘤学
✓ 已验证
产品关联
DOI
高影响因子
Pharmaceutics
·
2021
·Vol. 14
·期 1
·23
·
IF 6.321
Chenxin Duan,Wenwen Liu,Yunwen Tao,Feifei Liang,Yanming Chen,Xinyi Xiao,Guisen Zhang,Yin Chen,Chao Hao
Palbociclib (PAL) is an effective anti-breast cancer drug, but its use has been partly restricted due to poor bioavailability (resulting from extremely low water solubility) and serious adverse reactions. In this study, two cocrystals of PAL with resorcinol (RES) or orcinol (ORC) were prepared by evaporation crystallization to enhance their solubility. The cocrystals were characterized by single crystal X-ray diffraction, Hirshfeld surface analysis, powder X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared and scanning electron microscopy. The intrinsic dissolution rates of the PAL cocrystals were determined in three different dissolution media (pH 1.0, pH 4.5 and pH 6.8), and both cocrystals showed improved dissolution rates at pH 1.0 and pH 6.8 in comparison to the parent drug. In addition, the cocrystals increased the solubility of PAL at pH 6.8 by 2–3 times and showed good stabilities in both the accelerated stability testing and stress testing. The PAL-RES cocrystal also exhibited an improved relative bioavailability (1.24 times) than PAL in vivo pharmacokinetics in rats. Moreover, the in vitro cytotoxicity assay of PAL-RES showed an increased IC50value for normal cells, suggesting a better biosafety profile than PAL. Co-crystallization may represent a promising strategy for improving the physicochemical properties of PAL with better pharmacokinetics.Keywords:palbociclib;cocrystal;Hirshfeld surface;solubility;dissolution rate;physical stability
研究领域:
药学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2021
·Vol. 188
·期 11
·1-9
·
IF 5.833
Xia Yixuan,Ma Yuzhi,Wu Yuntao,Yi Yinhui,Lin Huiyu,Zhu Gangbing
A proof-of-principle concept for free-electrodeposited anodic stripping voltammetry (ASV) sensing of Cu 2+ is proposed by using Ti 3 C 2 T x MXene/carbon black (Ti 3 C 2 T x @CB) nanohybrids as electrode materials. Owing to the high adsorption and reduction capability of Ti 3 C 2 T x towards Cu 2+ , Ti 3 C 2 T x MXene enables Cu 2+ to be immobilized and self-reduced directly to form Cu 0 on the Ti 3 C 2 T x @CB electrode surface. As a result an oxidation peak current appears from the re-oxidation of Cu 0 via differential pulse voltammetry. Carbon black (CB) was introduced to prevent Ti 3 C 2 T x Mxene aggregation and improve the related electron transfer as well as enhance their surface area. After optimizing various conditions, a considerable low limit of detection (4.6 nM) and a wide linear range (0.01–15.0 μM) for Cu 2+ were achieved at the working potential from − 0.3 V to 0.0 V (vs SCE). Relative standard deviation (RSD) of eight individual Ti 3 C 2 T x @CB electrodes is 3.72%, and the recoveries from tap water sample and lake water sample were in the ranges of 97.0–108% and 104–107%, respectively. Graphical abstract
研究领域:
分析化学
·
材料科学
·
环境监测
✓ 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）