ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Shu-an Xia,Anqin Leng,Yao Lin,Li Wu,Yunfei Tian,Xiandeng Hou,Chengbin Zheng
A simple and miniature analytical system was developed to determine Hg and Cd in small amounts of samples by integrating flow injection capillary liquid electrode discharge (CLED) optical emission spectrometry (OES) and microplasma-induced vapor generation (PIVG) atomic fluorescence spectrometry (AFS). With the assistance of the inherent capillary driving force and the force arising from the solution vaporization in the microplasma, the sample solution was automatically transported into the discharge chamber wherein analytes were simultaneously excited to generate their atomic emission lines and converted to their volatile species. Subsequently, the volatile species were further swept into AFS for their further determination. Therefore, the same sample could be successively analyzed by OES and AFS. Owing to the unique independent linear-range and sensitivity of CLED-OES and PIVG-AFS, the developed system not only significantly extended its linear range to 6 orders of magnitude but also remarkably reduced the sample consumption to several microliters. Thus, wide linear-range and ultrasensitive determination of Hg and Cd in limited amounts of samples were accomplished simply by sharing one single capillary liquid electrode discharge source. Under the optimized conditions, limits of detection (LODs) of 10 μg L–1 were obtained for both Hg and Cd when CLED-OES was used as a detector, whereas the LODs for Hg and Cd were improved to 0.03 μg L–1 and 0.04 μg L–1 with AFS detector, respectively. In addition, the extremely wide linear-range of 0.001–100 mg L–1 and 0.001–40 mg L–1 were obtained for Hg and Cd, respectively. The potential application of this method was validated by successfully analyzing three Certified Reference Materials (ZK021-1, GBW(E)090033, and GBW(E)090034) and six human blood samples.
研究领域:
分析化学
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环境科学
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医学检测
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Wenjuan Fan,Junlian Qiao,Xiaohong Guan
A new method for Cr(VI) (0.025–8.00 mg/L) determination based on the reaction of Cr(VI) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) in aqueous solutions was developed. The colorless ABTS reacted with Cr(VI) under strong acidic conditions ([H + ] = 3.0 or 6.0 M) producing a stable colored radical ABTS + , which could be measured spectrophotometrically at 415, 649 or 732 nm. The absorbance increase at these three wavelengths for ABTS + generation were all linear (less than 1.0% deviation) with respect to the amount of added Cr(VI) and the sensitivity were 1.099 × 10 5 , 3.720 × 10 4 , and 4.150 × 10 4 M −1 cm −1 of added Cr(VI) at 415, 649 or 732 nm, respectively. Cr(VI) of 0.025 mg/L below the discharge standard of drinking water could be detected with the method quantitatively and 0.002 mg/L Cr(VI) was determined qualitatively. The molar absorptivity of ABTS + generated was determined to be (3.69 ± 0.01) × 10 4 M −1 cm −1 at 415 nm and the reaction between Cr(VI) and ABTS had a stoichiometric factor of 1:3 in excess of ABTS. The absorbance of generated ABTS + was found to be stable in deionized water or wastewater and Cr(VI) spiked in wastewater could be determined accurately. The ABTS method also had a good anti-interference performance against Co(II) ions. Moreover, the ABTS method could be successfully used in the Cr(VI)-S(IV) system for Cr(VI) determination.
研究领域:
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2019
·
IF 2.931
Jing Zou,Yixin Huang,Lirong Zhu,Zheng Cui,Baoling Yuan
A spectrophotometric method using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) as the indicator was proposed for measuring persulfates, i.e., peroxymonosulfate (PMS) and peroxydisulfate (PDS). This method was based on the direct oxidation of the colorless ABTS by PMS/PDS to generate the green-colored ABTS + at neutral pH and room temperature . The generated ABTS + had four different characteristic absorption peaks at 820 nm, 732 nm, 650 nm and 415 nm. The absorption values at these wavelengths increased with the increase of PMS/PDS concentration, and there were well linear relationships (R 2 > 0.998) between the corresponding absorption values and the concentrations of PMS/PDS in the range of 3–500 μM. Monitoring the change of PMS/PDS concentration by the proposed ABTS method was in good agreement with that monitored by the common spectrophotometric method using potassium iodide as the indicator. The green-colored waste solutions produced after PMS/PDS analysis with the ABTS method showed no bactericidal effect towards Escherichia coli . The proposed multi-wavelength spectrophotometric method using ABTS as the indicator could be employed as a candidate method for the accurate and convenient measurement of PMS/PDS in water.
研究领域:
分析化学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2019
·
IF 3.571
Wusigale,Lyulin Hu,Hao Cheng,Yahui Gao,Li Liang
Folic acid, a synthetic form of folate, is a water-soluble vitamin that is essential during periods of rapid cell division and growth. However, it decomposes upon ultraviolet irradiation to form inactive photoproducts. In this study, the protective effect and mechanisms of antioxidants, including cinnamic acids, flavonoids, catechol and its derivatives, stilbenes, p-benzoquinone and its derivatives, isoprenoids, curcumin, oleic acid, and linoleic acid, against folic acid photodecomposition were investigated by using fluorescence and absorbance spectroscopy, high-performance liquid chromatography, and antioxidant assay. It was found that antioxidants could inhibit or delay the folic acid decomposition in varying degrees, among which caffeic acid was the most effective. The increase in its remarkable antioxidant efficiency and absorbance in the UVA region during irradiation contributed to its effective protection. This finding could be useful for the protection of photolabile components in food and other uses.
研究领域:
营养学
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化学
·
食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2012
·
IF 2.545
Wei Feng,Changyin Lv,Liping Yang,Jianlin Cheng,Chengyan Yan
Melamine, a basic organic chemical intermediate, can cause renal failure because of the formation of insoluble melamine cyanurate crystals in the kidneys. This study examined a novel fluorescence spectrometry for the determination of trace melamine in dairy. The method was based on the inhibitory effect of melamine on the decolorizing reaction of the uncatalytic oxidation of acridine red by potassium permanganate in a sulfuric acid medium. The calibration graph was linear for melamine concentrations of 2.1 × 10 −4 –1.6 mg/L, and a detection limit of 61.5 ng/L was obtained. The melamine was determined in dairy samples by the proposed method after liquid–liquid and solid phase extraction. The results correlated with the high-performance liquid chromatography. The recoveries were within the range of 99.6–103.3% for liquid milk and 98.5–111.1% for milk powder. The possible mechanism of the reaction was also investigated by ultraviolet spectra.
研究领域:
分析化学
·
食品安全
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Xin Liu,Qi Fu,Peng Xu,Pengfei Zhu,Zhuoyu Yang,John C. Crittenden
A sensitive spectrophotometric method (the Br − -ABTS method) for measuring monopersulfate (PMS) of 0–20 μM in water was established. The Br − -ABTS method was based on the oxidation coloration reaction where Br − as catalyst promoted PMS for oxidation of ABTS forming the green-colored ABTS radical (ABTS • + ) under pH 3.0 (50 mM phosphate buffer). ABTS • + could be quantitatively measured at 415 nm, 650 nm, 732 nm and 820 nm using UV–vis spectrophotometer. There was a well linear relationship between the absorbance of ABTS • + and PMS concentration with the value of R 2 being 0.999. The proposed Br − -ABTS method was highly sensitive, and the absorbance generated by Br − -ABTS at 415 nm was 6.59 × 10 4 cm −1 per M (mol L –1 ) of PMS. The changes of pH from 3.0 to 9.0 had an insignificant effect on the calibration curve of Br − -ABTS method. The reaction of PMS with ABTS had a stoichiometric coefficient of 1:1.96 at the pH 3.0. The residual absorbance of ABTS •+ in ultrapure water, Xiangjiang water and Hou-lake water was stable within 30 min. Moreover, the trace PMS concentration of 0.03–20 μM in ultrapure water, 0.05–20 μM in natural water (e. g. Xiangjiang water and Hou-lake water) and 1–20 μM in wastewater was accurately measured with the proposed Br − -ABTS method. Additionally, the interference of natural water matrix (e. g. humic acid), metal ions (e. g. Co(II), Fe(III) and Cu(II)) and hydroxylamine had barely interference for the proposed Br − -ABTS method. Furthermore, the Br − -ABTS method was more accurate and flexible to determine PMS concentration than DPD method during the decolorization of rhodamine B in the Co(II)/PMS system, Cu(II)/PMS system and hydroxylamine/Fe(III)/PMS process.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
高影响因子
Arabian Journal of Chemistry
·
2013
·
IF 2.266
Ting Wen,Fei Qu,Nian Bing Li,Hong Qun Luo
In this work, we developed a facile, sensitive, and rapid spectrophotometric method for copper(II) ion detection in aqueous media using polyethyleneimine. Polyethyleneimine is a cationic polymer that has no absorption in the wavelength range of 250–800 nm. When trace amounts of copper(II) ion was added to the colorless polyethyleneimine solution, copper(II) ion could react with the amino groups of the polyethyleneimine to form a dark blue cuprammonium complex whose absorption spectrum exhibited two absorption peaks at 275 and 630 nm, respectively. The effects of parameters such as polyethyleneimine concentration, pH, temperature, reaction time, and the most suitable medium for the reaction were investigated. A linear relationship ( R 2 = 0.9997) between absorbance and the concentration of copper(II) ion was found at the maximum absorption peak of 275 nm in the concentration range of 2–400 μM. The detection limit for copper(II) ion was 566 nM. The response of polyethyleneimine toward different metal ions was investigated, and polyethyleneimine displayed a high selectivity for the copper(II) ion among the metal ions examined. This biocompatible and sensitive sensor may find applications in copper(II) ion detection in environmental and biological processes.
研究领域:
分析化学
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环境科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Xuefei Zhang,Fanfei Min,Lingyun Liu,Lujun Wang,Qi Liu
Ca 2+ is an important ion in industrial wastewater such as coal slurry water. The concentration of Ca 2+ directly affects the water quality of recycled water, the physicochemical properties of particle surfaces, and the effectiveness of coal beneficiation. However, the determination of Ca 2+ in coal slurry water is influenced by other coexisting metal ions (M: K + , Na + , Mg 2+ , and Al 3+ ) in the system. The complexation color development – visible spectrophotometry (CCDVS) has been proven to be a rapid and accurate way to determine Ca 2+ . This study investigates the impact and mechanism analysis of factors such as the concentrations of coexisting ions (K + : 0–15 mg/L, Na + : 0–2000 mg/L, Mg 2+ : 0–20 mg/L, Al 3+ : 0–0.05 mg/L) and valence states (monovalent, divalent, trivalent) on the accurate determination of Ca 2+ using the CCDVS method. All ions are interested in the indicator, with the light absorption intensity order of Al 3+ (Abs = −1.783) > Mg 2+ (Abs = −1.723) > Ca 2+ (Abs = −1.248) > K + (Abs = −0.268) > Na + (Abs = −0.075) under the same ions concentration (e.g. 16 mg/L). Interestingly, the absorbance of Ca–M mixed solutions shows different trends. For example, adding Na + decreases the absorbance value of Ca 2+ , with a decrease in Abs of 0.065 when the Na + concentration is 2000 mg/L. This indicates a competitive relationship between the complexation color development reaction of Ca and Na due to the same reaction mechanism. However, for Ca–Mg mixed solutions, when the Mg 2+ concentration increases to 15 mg/L, the increase in Abs is 0.078, attributed to the stronger absorption of Mg 2+ occupying the adsorption sites of Ca 2+ . On the contrary, at industrial concentrations, the influence of K + (0–20 mg/L) and Al 3+ (0–0.05 mg/L) on Ca 2+ detection can be ignored. Complementary characterization (XRD, XPS) and DFT theoretical calculations indicate that complexation color development reaction depends on the adsorption of metal ions on the sulfonic acid sites on the indicator. Other metal cations compete with Ca 2+ for the same adsorption sites, and the reactivity of metal ions with the indicator is as follows Al 3+ > Mg 2+ > Ca 2+ > K + > Na + . Therefore, this study provides technical and theoretical support for the development of highly selective Ca 2+ detection methods, aiding in the rational control of chemical agent dosages.
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
Food Biophysics
·
2016
·Vol. 12
·期 1
·78-87
·
IF 1.605
Wu Zhibing,Shen Liangliang,Han Qingguo,Lu Jun,Tang Haifeng,Xu Xu,Xu Hong,Huang Fengwen,Xie Jiangfeng,He Zhendan,Zeng Zheling,Hu Zhangli
Ligupurpuroside A is a glycoside extracted from Ku-Ding tea. As extracts from Ku-Ding tea exhibit anti-inflammatory property, we hypothesize that Ligupurpuroside A may be an active compound which inhibits trypsin activity during the anti-inflammatory process. The mechanism and nature of inhibition of trypsin by Ligupurpuroside A have been studied by multi-spectroscopic method, enzyme-activity assay and molecular docking. Enzyme activity assay reveals that Ligupurpuroside A significantly inhibits the activity of trypsin through a competitive manner with an IC 50 value of 3.08 × 10 −3 mol L −1 . Fluorescence titration together with thermodynamic analysis indicate that a Ligupurpuroside A-trypsin complex is formed, and that hydrophobic force and hydrogen bonding are the main forces stabilizing the complex. UV-vis absorption, synchronous fluorescence and circular dichroism spectra show that the interaction between Ligupurpuroside A and trypsin induces conformational changes of trypsin with a decrease in the contents of α-helix and β-sheet. Finally, molecular docking further suggests that Ligupurpuroside A molecule binds within the active pocket of trypsin via hydrophobic force and hydrogen bond. Results from this study of the interaction of trypsin with its natural inhibitor should be useful to minimize the antinutritional effects and make full use of tea extracts in the food industry, and be also helpful to the design of the drugs for the diseases related to overexpression of trypsin.
研究领域:
生物化学
·
药物设计
·
食品科学
✓ 已验证
DOI
高影响因子
Journal of Chemistry
·
2019
·
IF 1.727
Hao Zhou,Yilin Song,Zheng Yang
A coupled chip aiming at economical and highly selective ammonium detection was fabricated. It consisted of a reaction chip, a gas-diffusion chip, and a detection chip. Zinc tetraphenylporphyrin dyed on the cation-exchange resin microbeads was used as the indicating material to avoid excess consumption for its reversibility. PDMS was selected as the material of the gas-diffusion membrane. A portable spectrometer was applied for spectrum analysis. By analysis of spectrum change, the high selectivity was confirmed because no component had interference on detection effect. Good performance was shown for all the tested concentrations (0.2–50 mg·L−1). The stability and reversibility were also judged by the spectrum data obtained from the indicating process and the recovering process. Finally, real samples containing ammonium were tested and the results were compared to those came from a standard method to confirm the accuracy of our method.
研究领域:
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Kai-Qiang He,Xiao-Ru Zhang,Yuan-Peng Li,Xue-Lei Duan,Yan Li,Yang-Hong Jiang,Xiao-Dong Yuan,Ke-Gang Zhang,Chun-Gang Yuan
Along with the environmental protection policies becoming strict in China, the air pollution control devices (especially selective catalytic reduction (SCR)) are widely equipped in coal-fired power plants. The installation and run of these devices will inevitably affect mercury (Hg) species distribution in coal fired by-products such like fly ash (FA) and gypsum. In this work, a new on-line coupling system based on atomic fluorescence spectrometry (AFS) with a home-made chromatographic workstation was successfully developed to identify Hg species through thermal programmed desorption (TPD). The influences of matrix, furnace temperature, and carrier gas flow on analytical performance were investigated and the parameters were optimized. The FA and gypsum samples from coal-fired power plants equipped with SCR were collected and the mercury species were analyzed by the developed coupling system. HgCl 2 and HgO were the main species in FA, while Hg 2 Cl 2 and HgO were the main species in gypsum. All of Hg species in the studied FA and gypsum samples were released below 400 °C. A sequential extraction procedure was applied to further verify the operational Hg species including mobile and non-mobile fractions in FA and gypsum samples. This study demonstrated that AFS coupled with TPD procedure was an effective method to analyze Hg species in coal combustion by-products from power plants.
研究领域:
环境科学
·
能源与燃料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Yixin Huang,Jing Zou,Jiawen Li,Hongfang Ma,Siying Chen,Lingying Chen,Xiaobin Liao,Jun Ma
In this study, a rapid, sensitive and reliable spectrophotometric method for peroxydisulfate (PDS) determination in water was established. The proposed spectrophotometric method was based on the oxidation of 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate) (ABTS) to form stable and green-colored ABTS radical (ABTS • + ) by ferrous ion (Fe(II))-catalyzed PDS. The formed ABTS • + performed well linear relationship with PDS concentration (R 2 > 0.999) in the range of 0–60 μM at four wavelengths of 415, 650, 732, and 820 nm under optimized conditions. The proposed Fe(II)-ABTS spectrophotometric method was highly sensitive with the absorptivity of 3.595 × 10 4 M −1 cm −1 , 1.530 × 10 4 M −1 cm −1 , 1.945 × 10 4 M −1 cm −1 and 1.768 × 10 4 M −1 cm −1 at four detection peaks of 415, 650, 732 and 820 nm, respectively. Additionally, the proposed Fe(II)-ABTS spectrophotometric method possessed well anti-interference capacity to common natural water constituents and was reliable to determine PDS concentration in water. What’s more, the proposed Fe(II)-ABTS spectrophotometric method was successfully applied in monitoring the change of PDS concentration during the degradation of diclofenac in heat-activated PDS process. In a word, the proposed Fe(II)-ABTS spectrophotometric method could be employed as a promising approach for the rapid and accurate measurement of PDS in water, and this study provided a new perspective for the measurement of PDS by the visible spectrophotometry .
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）