MICROCHEMICAL JOURNAL
·
2019
·
IF 3.206
Ya Dan Li,Hui Hui Chai,Shu Jie Zhang,Zhi Song Lu,Chang Ming Li,Ling Yu
A sensitive and portable on-thread pre-concentration and colorimetric detection method of copper ions was proposed. Commercial cotton thread was proposed as a solid sorbent for effectively extracting copper ions (Cu 2+ ) from solution. The adsorbed Cu 2+ was converted to Cu + by ascorbic acid . The Cu + on the threads was visualized by horseradish-peroxidase-catalyzed color changes of a chromogenic oxidized tetramethylbenzidine substrate. The adsorption of Cu 2+ on the plasma- and Na 2 CO 3 -treated thread was verified by scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, and zeta potential characterization. The Cu + -induced dysfunction of HRP on the thread was verified by X-ray photoelectron spectroscopy. With optimized reaction conditions, the concentration-dependent colorimetric response plot was characterized, where the linear detection range was 2–400 nM and the detection limit was about 0.15 nM. Measurements of a group of possible interfering ions and spiked real-water samples demonstrated the good selectivity of the proposed method. The proposed on-thread pre-concentration and colorimetric detection offers a low-cost and effective alternative for detecting of copper ions in real applications.
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
MICROCHEMICAL JOURNAL
·
2022
·
IF 5.304
Chu Chu,Linmin Lian,Wei Gao,Yaping Zang,Yanfang Zou,Yangbin Lv,Chenyue Li,Shengqiang Tong,Jizhong Yan,Suhong Chen
An efficient off-line and on-line synergistic preconcentration strategy which involves combining micro matrix solid-phase dispersion (MSPD) with electrokinetic supercharging (EKS) in capillary zone electrophoresis (CZE) has been developed for the determination of two alkaloids, lycorine and galanthamine, in complicated matrix samples. This method was comprehensively optimized in terms of the buffer condition, the leading electrolyte (LE), terminating electrolyte (TE), the sample injection in EKS preconcentration, as well as the dispersing sorbent, the sample/dispersing sorbent mass ratio, grinding time, eluting solvent in MSPD procedure. Under the optimum conditions, lycorine and galanthamine, achieved about 1500- and 1200-fold sensitivity improvement respectively when compared to the ordinary injection. A satisfactory correlation coefficient (R 2 > 0.9982) was obtained in the range of 10–500 ng/mL. The limits of detection (LODs) for lycorine and galanthamine were 6.0 ng/mL and 8.0 ng/mL, respectively. Moreover, the proposed method was successfully applied in two real samples, rat fecal samples and Bulbus Lycoridis Radiatae, to demonstrate its feasibility. Recoveries in spiked fecal and plant samples were 89.51% to 107.4%. The result showed that the new developed method possessed the great potential in analyzing trace alkaloids in complicated samples matrix.
研究领域:
分析化学
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药理学
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DOI
高影响因子
DESALINATION
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2022
·
IF 11.211
Weilong Song,Shuyue Liu,Ming Xie,Pin Zhao,Xinhua Wang
Using seawater desalination concentrate (SC) as DS of FO for simultaneous wastewater pre-concentration and disposal of waste SC has presented good application potential. Nevertheless, knowledge of membrane fouling mechanisms in FO process using SC as DS, especially the influence of SC on membrane fouling, is still inadequate, mostly due to the limited operation time in previous studies. Hence, present study focused on membrane fouling behaviors in FO with SC as DS, with particular focus on impact of SC in long-term operation. The results indicated that using SC as DS induced noticeable aggravation of membrane fouling on both active layer (AL) and support layer (SL) sides of FO membrane in long-term operation, which was not observed in short-term operation. On AL side, accumulation of Ca 2+ and Mg 2+ via back-diffusion from SC became significant during long-term operation, thereby substantially altered fouling behavior on AL side, resulting in more refractory membrane fouling. On SL side, calcium-based scaling was formed both in and within the porous matrix of SL during long-term operation. Accordingly, a combined membrane cleaning strategy (NaClO for AL + HCl and EDTA for SL) was developed. The results could facilitate the application of SC as an economical and feasible DS source.
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
MICROCHIMICA ACTA
·
2011
·Vol. 176
·期 3
·359-366
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IF 2.578
Cui Yang,Hu Zhang-Jun,Yang Jia-Xiang,Gao Hong-Wen
We have covalently grafted phenyl-iminodiacetic acid groups onto multi-walled carbon nanotubes via a diazotation reaction. The resulting material was characterized by FT-IR and UV–vis spectroscopy, by TGA, XPS and SEM. It is shown to be a valuable solid-phase extraction adsorbent for the preconcentration of trace quantities of Fe(III), Cu(II) and Pb(II) ion from aqueous solution prior to their determination by ICP-OES. Various factors affectting the separation and preconcentration were investigated. The enrichment factor typically is 100. Under optimized experimental conditions, the maximum adsorption capacities for Fe(III), Cu(II) and Pb (II) are 64.5, 30.5 and 17.0 mg g-1, respectively, the detection limits are 0.26, 0.15 and 0.18 ng mL-1, and the relative standard deviations are <2.5% ( n = 6). The new adsorbent shows superior reusability and stability. The procedure was successfully applied to the determination of trace quantities of Fe(III), Cu(II) and Pb (II) in water samples.
Multiwalled carbon nanotubes grafted with phenyl-iminodiacetic acid (PIDA-MWCNTs) is prepared and employed as solid phase extraction sorbent to determinate the trace Fe(III), Cu(II) and Pb (II) in water samples. The method has been applied to the preconcentration of trace amount of Fe(III), Cu(II) and Pb (II) in water samples with satisfactory results.
研究领域:
环境化学
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分析化学
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材料科学
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水污染监测
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痕量金属检测
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DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2023
·Vol. 24
·期 18
·13751
·
IF 5.6
Hsin-Hua Liang,Yu-Chao Lin,Chin-Chuan Hung,Yu-Chi Hou,Yi-Hui Lin
In this study, we established a novel capillary electrophoresis method for monitoring the concentration of doripenem in human plasma. As a time-dependent antibiotic, doripenem maximizes its antibacterial effects and minimizes the potential for antibiotic resistance through careful therapeutic drug monitoring. Two online preconcentration techniques, field-enhanced sample stacking (FESS) and sweeping, were coupled to enhance the detection sensitivity. Briefly, an uncoated fused silica capillary (40 cm × 50 μm i.d) was rinsed with a high conductivity buffer (HCB) composed of 150 mM phosphate buffer (NaH2PO4, pH 2.5) and 20% methanol. A large sample plug prepared in a low-conductivity phosphate buffer (50 mM NaH2PO4, pH 2.5) was then hydrodynamically injected (5 psi, 80 s) into the capillary. Under an applied voltage of −30 kV, the analyte was accumulated at the FESS boundary and swept by the negatively charged micelles toward the UV detector. Plasma samples were pretreated by solid-phase extraction (SPE) to eliminate endogenous interferences. The validation results demonstrated a high coefficient of determination (r2> 0.9995) for the regression curve with impressive precision and accuracy: relative standard deviation (RSD) <5.86% and relative error <4.63%. The limit of detection (LOD, S/N = 3) for doripenem was determined to be 0.4 μg/mL. Compared to the conventional micellar electrokinetic chromatography method, our developed method achieved a sensitivity enhancement of up to 488-fold for doripenem. Furthermore, the newly developed method successfully quantified doripenem concentrations in plasma samples obtained from patients accepting doripenem regimens, proving its application potential in the clinical realm.Keywords:carbapenems;doripenem;FESS-sweeping MEKC;human plasma;online preconcentration
研究领域:
分析化学
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临床医学
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药理学
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DOI
PubMed
高影响因子
Analytical Methods
·
2012
·Vol. 5
·期 4
·1046-1051
·
IF 1.547
Juan-Juan Ye,Wei Feng,Miao-Miao Tian,Jun-Ling Zhang,Wei-Hong Zhou,Qiong Jia
A novel magnetic adsorbent, magnetic microsphere functionalized with Cyanex272, has been successfully synthesized via a chemical bonding alkylation method. A flow injection on-line preconcentration, with a micro-column packed with the as-synthesized magnetic adsorbent, coupled with UV-Vis spectrophotometric method was developed for the determination of phenol at a wavelength of 270 nm. Various experimental parameters were optimized as follows: eluent (methanol), sample flow rate (1.4 mL min−1), sample volume (1.4 mL), sample pH (5.0), and eluent flow rate (2.2 mL min−1). Under the optimum conditions, the intra-day and inter-day relative standard deviations were 1.37% and 2.69% (n = 5), respectively. The proposed method has been successfully applied to the determination of phenol in phenol ear drops, compound borax solution, and phenol ointment samples and the accuracy was assessed through recovery experiments.
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
Journal of the Iranian Chemical Society
·
2015
·Vol. 13
·期 2
·331-337
·
IF 1.087
Fan Chunlei,Pan Qinhe,Li Qun,Wang Liyuan
In this work, cloud point-TiO 2 /sepiolite composites–octyl alcohol extraction combined with UV–vis spectrometry was applied to analyze nickel in real samples. Trace nickel was separated and preconcentrated with PAN as chelating agent, and TiO 2 /sepiolite composites—octylphenoxypolyethoxyethanol (TX-114)—octyl alcohol as extraction agent. Factors influencing extraction efficiency, such as concentrations of TX-114 and octanol, type of the desorption on the extraction system, concentration of chelating agent, pH, incubation temperature, incubation time and conditions of phase separation were investigated and optimized systematically. The results showed that TiO 2 /sepiolite composites exert significant effects on the extraction efficiency; especially nickel concentration is very low. Under the optimal conditions, the absorbance signal is linear with nickel concentration in the range of 0.02–3 mg L −1 and the detection limit was 5 μg L −1 . The developed method was successfully applied to the determination of nickel in natural products of Baisha green tea and coconut water in Hainan.
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
MICROCHEMICAL JOURNAL
·
2017
·
IF 3.034
Agustín G. Crevillén,Mercedes de Frutos,José Carlos Diez-Masa
Isotachophoresis (ITP) coupled to zone electrophoresis (ZE), either free zone electrophoresis (FZE) or gel electrophoresis (GE), carried out mainly in capillaries and, although less frequently, also in microchips, is a powerful preconcentration and separation technique which has been successfully used for the study of many low molecular-weight analytes. However, this analytical technique has been scarcely applied for proteins separation. In this work, an on-chip transient ITP coupled to free zone electrophoresis (t-ITP-MFZE) mode with LIF detection is developed for the preconcentration and separation of the proteins α-lactalbumin and β-lactoglobulin. Firstly, for LIF detection, the proteins were off-chip fluorescently labeled with the fluorogenic reagent Chromeo P503. Then, several separation parameters in t-ITP-MFZE mode such as leading electrolyte, terminating electrolyte, separation voltage, and injection time were optimized to achieve the maximum sensitivity while maintaining an adequate resolution between α-lactalbumin and β-lactoglobulin in a single column configuration t-ITP. Using the optimized electrolytes (50 mM imidazole/HCl pH = 8 as leading electrolyte and 100 mM imidazole/12 mM HEPES pH = 8 as terminating electrolyte) separation of both proteins was achieved in less than 4 min with peak resolution of 1.5. The LODs were 55 nM and 380 nM, for α-lactalbumin and β-lactoglobulin, respectively, which are adequate for some food allergenicity studies. Finally, comparison of the optimized t-ITP-MFZE method to the equivalent MFZE method, carried out also in microchips but without the isotachophoretic preconcentration step, provided preconcentration indexes for both proteins around 10.
研究领域:
分析化学
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蛋白质组学
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生物技术
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DOI
高影响因子
ELECTROPHORESIS
·
2020
·Vol. 42
·期 4
·465-472
·
IF 3.081
Qiuyue Xu,Beibei Chen,Man He,Bin Hu
Ti (IV)-modified vinyl phosphate magnetic nanoparticles (Fe 3 O 4 @SiO 2 @KH570-PO 4 -Ti (IV)) was prepared for simultaneous extraction of multiple arsenic species, followed by high performance liquid chromatography (HPLC)– inductively coupled plasma mass spectrometry (ICP-MS) analysis. Inorganic arsenic (iAs), dimethyl arsenic acid (DMA), monomethyl arsenic acid (MMA), p -amino phenyl arsenic acid ( p -ASA), 4-hdroxyphenylarsenic acid (4-OH), phenyl arsenic acid (PAA), and 3-nitro-4-hydroxyphenylarsenic acid (ROX) were investigated as interest analytes. It was found that they were quantitatively adsorbed on Fe 3 O 4 @SiO 2 @KH570-PO 4 -Ti (IV) at pH 5, and desorbed completely with 0.1 mol/L sodium hydroxide solution. Enrichment factor of 100-fold was obtained by consuming 100 mL sample solution. Under the optimal conditions, the method combining MSPE with HPLC-ICP-MS presented a linear range of 1–5000 ng/L for seven arsenic species. The limits of detection were 0.39, 0.60, 0.23, 1.85, 0.54, 0.48, and 0.84 ng/L for DMA, MMA, p -ASA, iAs, 4-OH, PAA, ROX, with the relative standard deviations ( c = 10 ng/L, n = 7) of 3.6, 3.9, 5.5, 12.4, 6.1, 5.8, 5.0, respectively. The accuracy of the method was validated by analyzing BCR 627 Tuna fish. The application potential of the method was further evaluated by chicken muscle and liver samples. No target arsenic species were detected in these samples, and good recoveries (80.6–123%) were obtained for the spiked samples at low, medium, and high concentration levels.
研究领域:
分析化学
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环境科学
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食品科学
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DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2020
·
IF 6.551
Yisong Hu,Ying Zang,Yuan Yang,Ao Duan,Xiaochang C. Wang,Huu Hao Ngo,Yu-You Li,Runda Du
Wastewater preconcentration to capture abundant organics is promising for facilitating subsequent anaerobic digestion (AD) to recover bioenergy, however research efforts are still needed to verify the effectiveness of such an emerging strategy as carbon capture plus AD. Therefore, lab-scale anaerobic dynamic membrane bioreactors (AnDMBRs) without and with the addition of zero-valent iron (ZVI) (i.e., AnDMBR1 versus AnDMBR2) were developed for preconcentrated domestic wastewater (PDW) treatment, and the impact of ZVI addition on process performance and associated mechanisms were investigated. The stepwise addition of ZVI from 2 to 4 to 6 g/L improved the treatment performance as COD removal slightly increased and TP removal and methane production were enhanced by 53.3%–62.9% and 22.6%–31.3%, respectively, in consecutive operational phases. However, the average increasing rate of the transmembrane pressure (TMP) in AnDMBR2 (0.18 kPa/d) was obviously higher than that in AnDMBR1 (0.05 kPa/d), indicating an unfavorable impact of dosing ZVI on the dynamic membrane (DM) filtration performance. ZVI that has transformed to iron ions (mainly Fe 2+ ) can behave as a coagulant, electron donor or inorganic foulant, thus enabling the excellent removal of dissolved phosphorous, enhancing the enrichment and activities of specific methanogens and causing the formation of a compact DM layer. Morphological, componential, and microbial community analyses provided new insights into the functional mechanisms of ZVI added to membrane-assisted anaerobic digesters, indicating that ZVI has the potential to improve bioenergy production and resource recovery, while optimizing the ZVI dosage should be considered to alleviate membrane fouling .
研究领域:
环境工程
·
微生物学
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DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2020
·
IF 3.594
Jing Xiao,Hao Wang,Chunxiang Li,Keqin Deng,Xiaofang Li
High-quality tremella-like graphdiyne (GDY) nanotubes composed of intertwined ultrathin nanosheets were acidified. Shortened and acidified multi-walled carbon nanotubes (S-MWCNTs) were simply blended with GDY in a certain proportion to modify glassy carbon electrode (GCE). Electrochemical behavior of DA was studied on different modified electrodes . GDY showed high preconcentration to DA. S-MWCNTs facilitated the electron transport and promoted the oxidation of DA. Differential pulse voltammetry (DPV) was applied to determine low concentrations of DA. It exhibited a linear response in the concentration range of 0.02 to 20.0 μM with an estimated detection limit of 8.6 nM (S/N = 3). This sensor showed excellent performances for detection of DA in biological fluids.
研究领域:
分析化学
·
生物医学工程
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产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2021
·
IF 4.821
Yu-Qi Liu,Bin Ji,Xiang-Hong Yan,Shuang Lv,Fang Fang,Xiao-Lin Guo,Zhi-Yong Wu
A microfluidic paper-based analytical device (PAD) with both pre-concentration and parallel operation functions is of great promise for sensitive and high throughput detection. In this paper, a fast and multiplexed PAD was designed based on wax-screen-printing with glass fiber paper substrate and validated by image-based colorimetry. Driven by the same DC power supply, parallel electrokinetic stacking with the PAD of 8 channels can be completed within 2 min, and each channel can be loaded with different samples. Enrichment factor of 2 orders of magnitude was demonstrated with RSD below 2.5% between the chips and the channels of a chip. Reproducible and multiplexed stacking operations of this PAD provide a solid foundation for online calibration and sample detection on the same chip at the same time. Applications of this PAD was demonstrated by online colorimetric detection of food pigments from beverages and offline MS/MS detection of amino acids from a serum sample. Besides high-throughput and sensitive point-of-care test detection, this PAD method could also find applications for efficient pre-separation and pre-concentration of complex samples.
研究领域:
分析化学
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生物医学工程
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诊断学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）