Analytical Methods
·
2019
·Vol. 11
·期 11
·1469-1474
·
IF 2.378
Ping Chen,Hui Zhong,Xiang Wang,Changdong Shao,Sanjun Zhi,Xiao-Rong Li,Changmei Wei
Ascorbic acid (AA), as a key coenzyme in human metabolic pathways, plays an important role in various physiological reactions. An abnormal level of AA is found to be associated with several diseases. In this paper, we developed a label-free colorimetric method for the determination of AA by using manganese dioxide (MnO2) nanosheets. Once AA was introduced, MnO2 was reduced to Mn2+, which resulted in a remarkable color fading of MnO2 nanosheet solution. Thus, AA can be quantified by photometry in a linear range from 0.1 to 20 μM with a detection limit of 98 nM. The detection strategy possesses the advantages of versatility and low cost and shows great potential for AA detection in clinical medicine and food safety.
研究领域:
分析化学
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医学检验
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食品安全
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产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Xuefei Zhang,Fanfei Min,Lingyun Liu
Ca 2+ is an important cation in coagulants used in the treatment of mine wastewater such as coal slime water, and its concentration directly affects the settling and flotation of coal slime water. The rapid determination of Ca 2+ concentration is of great significance to guiding industrial production. Herein, the complexation color development—visible spectrophotometry (CCDVS) method was proposed to obtain the concentration information of Ca 2+ , wherein 1-(1-Hydroxy-4-methyl-2-phenylazo)-2-naphthol-4-sulfonic acid (Calmagite) was used as an indicator and the mechanism of complexation between the indicator and Ca 2+ was explored. The strong correlation between spectral data and Ca 2+ concentration (R 2 = 0.997) indicated that this method could be used for Ca 2+ detection, thereby a quantitative model was proposed to predict Ca 2+ concentration by using the complexation color development—visible light absorption data. The chemical element and bonding analysis confirmed that Ca 2+ was complexed with the sulfonic acid group on the indicator skeleton in the form of Ca(OH) + intermediate in an alkaline environment. The generated complexation product (-S-O-Ca(OH) + ) could stably absorb 620 nm light energy, and its absorption performance remained 99.8% after standing for 60 min. The relative standard deviation of the detection results of Ca 2+ in different calcium source solutions was as low as 1.24%, which confirmed the strong calcium source compatibility of the proposed method. More importantly, the successful application of this method in the determination of Ca 2+ concentration at different points in industrial coal slime water system proved its advantages of high accuracy (relative error is as low as 5.01%), low cost and simple operation. The LOD of this method is 0.038 mg/L. Therefore, the complexation color development—visible spectrophotometry method can maximize the potential for cost reduction and efficiency improvement in mine wastewater treatment.
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
Current Pharmaceutical Analysis
·
2022
·Vol. 18
·期 2
·199-207
·
IF 0.743
Yang Ping,Luo Jinhua,Yan Shuo,Li Xiaohong,Yao Qian
Background: Cyclodextrins (CDs) are commonly used host molecules of inclusion complex. However, due to the lack of a sensitive determination method, the absorption process of CDs remains unclear. Objective: In this study, an oleuropein (OL) inclusion complex employing hydroxylpropyl-betacyclodextrin
(HP-beta-CD) as host molecules was prepared and the formation of inclusion complex was ascertained by FT-IR and DSC. Spectrophotometry was established for the determination of HP-beta-CD, based on the fact that the absorbance of phenolphthalein (PP) decreased in the presence of HP-beta-CD.
Methods: The assay conditions were optimized to augment the method sensitivity. Molecular docking was employed to verify the strong interaction between PP and HP-beta-CD. The permeation process of free HP-beta-CD, HP-beta-CD of OL inclusion complex, free OL, and OL in the inclusion complex,
was examined using an in vitro mouse small intestine model. Results: Though HP-beta-CD possessed a hydrophilic outside shell, it could permeate through the mouse small intestine quickly with a cumulative permeating amount of over 90% in 2 h. Free HPbeta- CD, the host molecule HP-beta-CD,
and guest molecule OL of the inclusion complex exhibited consistent permeating profiles across the mouse small intestine. Conclusion: The approach for the determination of HP-beta-CD was accurate and precise (%RSD=2.98).
研究领域:
药剂学
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生物药剂学
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药物分析
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DOI
高影响因子
OPTIK
·
2018
·
IF 1.191
Zhonghua Wang,Haiqian Zhao,Ming Dong,Xue Cui,Xiaoyan Liu,Yang Liu
It is significant to quantitative test ·OH for understanding the reaction mechanisms of Fenton . OH concentration was directly measured in Fenton system via the spectrophotometric method based on Russell mechanism, and the drawbacks were analyzed. The influences of H 2 O 2 and dimethyl sulfoxide (DMSO, the trapping agent of OH) on the spectrophotometric measurement were studied. The Fe 2+ /Fe 3+ concentrations were tested during the Fenton reaction . The results show that it was difficult to detect ·OH directly in Fenton system. The effect of DMSO on the detection of diazosulfones was related to its concentration. Under most conditions (DMSO concentration was lower than 2000 mmol L −1 ), DMSO did not affect the detection of diazosulfones. The interference of DMSO on the colour reaction was weak. H 2 O 2 had a significant influence on the test result by reacting with methyl radicals, diazosulfones, and disturbing the colour reaction. High concentration of H 2 O 2 was the main reason why OH concentration was hard to be detected in Fenton system. A low concentration of H 2 O 2 was beneficial for decreasing the influence of H 2 O 2 on the measurement. The concentration ratio of Fe 3+ to Fe 2+ remained approximately constant in the Fenton system except during the short initial stage. Based on the analysis, a modified spectrophotometric method for OH concentration test in Fenton system was proposed. In this method, the H 2 O 2 solution was slowly added into the Fe 2+ /Fe 3+ system obtained from the Fenton solution. The test results showed that the ·OH concentration increased linearly with the consumption amount of H 2 O 2 .
研究领域:
环境科学
·
分析化学
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DOI
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
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2019
·Vol. 11
·期 45
·5793-5802
·
IF 2.378
Rui Zhang,Mengxin Zhang,Yi Zhang,Heng Yan,Xing Li,Wei-hong Xie
A screening method for the simultaneous detection of the synthetic food dyes tartrazine (TA), Sunset Yellow (SY), Allura Red (AR), Ponceau 4R (PO), Amaranth (AM), and Bright Blue (BB) in different samples was developed. The measurements were performed on a spectrophotometry microplate reader and the concentrations of the dyes in samples were calculated using a multi-primary linear equation group. Standard solutions containing dye concentration ranges from 4–35 μg mL−1 and carbonated beverages from supermarkets were used to evaluate the precision and accuracy of the method. Six-equation groups and three-equation groups were used to predict the dye concentrations in the mixtures or in the drinks. The results indicated that the three-equation groups gave better predictions for dyes, both in the standard mixture solutions and in the carbonated beverages. The recoveries of the dyes from the drink samples were 70–108% when the spiked concentrations were 5 μg mL−1 and 10 μg mL−1, with a RSD range of 0.01–0.33%. In comparison with high performance liquid chromatography (HPLC), the method could find most of the additive dyes in the drinks with a low detection limit of around 2 μg mL−1. The standard deviations of six repeat measurements from one plate and three repeat measurements among three different plates were both within ±0.5 μg mL−1. We also tried to identify three red dyes with highly overlapping spectra: AR, PO, and AM; the results indicated that the method could also identify the three red dyes in mixed solutions.
研究领域:
分析化学
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食品安全
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产品关联
DOI
高影响因子
ANALYTICAL BIOCHEMISTRY
·
2022
·
IF 3.191
Guozeng Wang,Zhihao Jiang,Qing Xiao,Chang Jiang,Xian'ai Shi
Omega-transaminases (ω-TAs) have attracted considerable interest for their use in asymmetric synthesis of chiral amines with a high degree of optical purity and yield. The rapid evaluation of the characteristics of newly identified or engineered ω-TAs is important for industrial applications. In this study, a visible spectrophotometric assay was developed for rapid quantitative determination of ω-TA activities based on the transamination of 2-(4-nitrophenyl)ethan-1-amine to generate a red product ( E )- N -(4-nitrophenethyl)-2-(4-nitrophenyl)ethen-1-amine. After various co-solvents were evaluated, dimethyl sulfoxide (DMSO) was considered optimal because the red product exhibits good solubility and retains its original color. The red product dissolved in DMSO has its highest absorbance at 465 nm, and its concentration has a good linear relationship with the absorbance. A spectrophotometric assay was established and validated using conventional HPLC analysis (<10% divergence). This method was then used to characterize an ω-TA from thermophilic Geobacillus thermoleovorans and an ω-TA obtained from the metagenome of a soda lake. The results demonstrated that ω-transaminase enzymatic properties could be characterized simply, rapidly, and at low cost, using this newly established visible spectrophotometric assay method.
研究领域:
生物化学
·
工业酶学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2015
·Vol. 183
·期 2
·625-631
·
IF 3.741
Ding Caiping,Yan Yinghan,Xiang Dongshan,Zhang Cuiling,Xian Yuezhong
Greigite magnetic nanoparticles (Fe 3 S 4 -MNPs) were prepared and reveal a peroxidase-like activity. Kinetic studies revealed a pseudo-enzymatic activity that is much higher than that of other magnetic nanomaterial-based enzyme mimetics. This finding was exploited to design a photometric enzymatic glucose assay based on the formation of H 2 O 2 during enzymatic oxidation of glucose by glucose oxidase, and the formation of a blue product from an enzyme substrate that is catalytically oxidized by H 2 O 2 in the presence of Fe 3 S 4 -MNPs. Glucose can be detected in the 2 to 100 μM concentration range, and the low detection limit is 0.16 μM. The method was applied to quantify glucose in human serum. In our perception, this enzyme mimetic has a large potential in that it may be used in other oxidase based assays, but also in ELISAs.
Fe 3 S 4 magnetic nanoparticles (MNPs) are shown to act as peroxidase mimetics and this was used to design a glucose oxidase (GOx) based glucose assay where the H 2 O 2 formed during oxidation of glucose oxidizes tetramethylbenzidine (TMB) to give a blue product which can be quantified by photometry.
研究领域:
生物化学
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医学检测
·
纳米材料科学
✓ 已验证
DOI
高影响因子
Journal of Chemistry
·
2019
·
IF 1.727
Fei Chang,Zhong Bing He,Quan Zhou
Four kinds of Al-TiO2 solid samples with different Ti/Al ratios of 1 : 0.1, 1 : 0.09, 1 : 0.07, and 1 : 0.05 were synthesized via a solid-phase synthesis method and characterized by XRD, SEM, EDS, BET, and other techniques. The prepared solids were used for separation of the bioderived product danshensu, the content of which was determined by UV spectrophotometry. Moreover, the effects of extract concentration, PH value, adsorption time, and ethanol elution volume were investigated. The results showed that these Al-TiO2 samples had good adsorption and desorption ability. Especially, the solid Al-TiO2 with a Ti/Al ratio of 1 : 0.05 is more suitable for the separation of danshensu, exhibiting a higher adsorption (77.70%) under 2 h adsorption time and pH = 3; meanwhile, the high desorption rate (70.29%）was received under 80% ethanol and the sample concentration of 3.0 mg/mL.
研究领域:
材料科学
·
分析化学
·
药学
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产品关联
DOI
高影响因子
JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
·
2017
·Vol. 28
·期 8
·1475-1482
·
IF 1.198
Xu Zhiqun,Wu Qiao,Duan Yunjian,Yang Meixia,Ou Minrui,Xu Xiaoping
Bisphenol A (BPA) is an industrial material which can lead to endocrine disorders. In this work, a simple and sensitive spectrophotometric method for determination of BPA using diazotization-coupling reaction was presented. To achieve the best performance of the developed method, the experimental parameters were optimized in terms of reagent concentration, reaction time, pH, and temperature. Under the optimal conditions, the absorbance increased linearly with the increasing concentration of BPA in the range of 0.16-10.4 µg mL-1 with the correlation coefficient of 0.9991 and the detection limit of 0.05 µg mL-1. Results achieved with the spectrophotometric method were compared with those obtained using high performance liquid chromatography (HPLC) method. The proposed method was successfully applied to determine BPA in milk and water bottle samples and satisfactory results were obtained, which make it very suitable for routine analysis of BPA in quality control laboratories.
研究领域:
分析化学
·
环境科学
·
食品安全
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2014
·
IF 1.552
Xianfeng Fu,Jianyong Zheng,Xiangxian Ying,Hongde Yan,Zhao Wang
A novel ultraviolet (UV) spectrophotometric method for evaluating lipase transesterification activity in organic solvents is described. The model reaction was lipase-catalyzed transesterification between p -nitrophenyl palmitate (pNPP) and n -butanol in n -hexane at 30 °C. The conversion of pNPP to p -nitrophenol was monitored by measuring UV absorbance changes at 310 nm. Seven commercial lipases were tested using this method, and the results were similar to those obtained using gas chromatography . The UV spectrophotometric method was used to investigate the kinetics of the Lipozyme TL IM-catalyzed reaction of pNPP, and the correlation between synthetic activity and biocatalyst concentration was determined. The method was also used to investigate the Lipozyme TL IM-catalyzed transesterification properties, namely solvent effect, acyl acceptor specificity, alcohol tolerance, optimum reaction temperature, and thermostability.
研究领域:
生物化学
·
酶工程
✓ 已验证
DOI
高影响因子
Journal of Analysis and Testing
·
2022
·Vol. 7
·期 2
·157-162
·
IF 0
Gao Su,Ye Ming-Liang,Ma Rui,Liu Ai-Rong,Gao Hong-Wen
Based on the Mg 2 + complexation with acid chrome blue K (ACBK) at pH 10.2, an automatic system was designed to determine total hardness of water. The system consists of a vector colorimeter, a multi-channel sampling pump and both reagents A and B. Two kinds of reagent solutions were prepared and used in this system, i.e., ammoniacal buffer and ACBK—disodium magnesium EDTA solutions. The experimental results of the standard solutions containing 2 and 3 mg/L of total hardness showed that the relative standard deviations (RSDs) were 1.9% and 2.2%, respectively, and the limit of detection (LOD) was only 0.035 mg/L. The detection of four natural water samples showed that the recoveries were between 85.0% and 108.6%, consistent with those obtained by ICP-AES method.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
危险品化学品经营许可证（带存储）