ANALYTICAL LETTERS
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2024
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IF 1.6
Zekun Tang,Huihui Wan,Huaishuan Zhang,Yu Zhang,Min Ju,Jinfeng Zhao,Yuming Sun,Lina Zhou,Qingxin Yin,Rui Cai,Qiang Xu,Yuming Song,Hua Zhang
As an important circulating metabolite in the body, the accurate determination of glucose in body fluids is very important for the evaluation of physiological status. However, liquid chromatography–mass spectrometry (LC–MS) methods present challenges for glucose due to poor ionization combined with weak chromatographic retention. Here, a method for determining salivary glucose using LC–MS after derivation by dibenzylamine is described in which 3-O-methyl-D-glucopyranose was used as internal standard. Saliva samples were prepared by protein precipitation, and the analytes were separated on a polar-copolymerized C18 reversed phase column. Detection took place by high-resolution orbitrap mass spectrometry after ionization in the positive mode. The calibration function was linear from 0.35 to 50 ng/mL. The recoveries were from 97.82 to 104.51% for intraday assays and 98.96 to 106.61% for interday assays. The intraday precision of salivary glucose was from 0.37% to 1.43% and the interday precision from 1.33% to 1.43%. The limits of detection and quantification in saliva were 0.2 and 0.6 ng/mL. The samples after derivatization were stored at 4 °C and 25 °C and analyzed every two days with five repeats. The relative standard deviations were 0.09% and 0.27% at 4 °C and 25 °C. This method was employed for the determination of the glucose in saliva for healthy male college students after exercise.
研究领域:
分析化学
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医学
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DOI
高影响因子
CHROMATOGRAPHIA
·
2022
·Vol. 85
·期 5
·395-403
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IF 2.213
Tang Zekun,Ye Fanfan,Wan Huihui,Song Yuming,Fan Weiwei,Chi Zhanyou,Du Qinqin,Cai Rui,Xu Qiang,Zhang Hua
Liquid chromatography–mass spectrometry (LC–MS) technique has been widely used for the determination of trace carbohydrate compounds in biological samples. However, the ionization efficiency of carbohydrates under the conditions of common electrospray ion sources is poor, and thus chemical derivatization treatment is usually needed. Here, a pre-column derivatization based on dibenzylamine method coupling with LC–MS/MS was developed for the analysis of glucose, xylose, ribose, galactose, maltose, and maltotriose. Aldosaccharide compounds were labeled by dibenzylamine within 3 h at 75 °C. The derivatized aldosaccharides were separated on a polar-copolymerized C18 column and identified with electrospray ionization mass spectrometer in positive mode. The dibenzylamine-derived product of 3-O-methyl-D-glucopyranose was used as the internal standard for the quantitation of derivatized aldosaccharide products. Under the optimized condition, good correlation coefficients ( R 2 > 0.9903) for all carbohydrates were obtained. Outstanding sensitivity with limits of quantitation (S/N 10) of 0.35–20 ng mL −1 and limits of detection (S/N 3) of 0.1–7 ng mL −1 were achieved. The developed method was successfully utilized for the determination of aldosaccharides in sample of corn stalk fermentation. The recoveries of the method were in the range of 92.59–103.22% with relative standard deviations of 1.08–6.08%.
研究领域:
分析化学
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生物化学
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发酵技术
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DOI
高影响因子
Advanced Materials Interfaces
·
2021
·Vol. 8
·期 11
·2100013
·
IF 6.147
Rongxiu Guo,Guangqi He,Xinyu Chen,Xinyue Zhang,Ze-nan Hu,Xiaodong Li,Dun Niu,Hong-bin Sun
Surface wettability of heterogeneous catalysts plays a crucial role in the catalytic activity and selectivity. In this work, an ultra-thin modified silica coating is firstly used as the “skin” to adjust the surface hydrophilicity of the catalyst, which promotes the catalytic activity and selectivity in the transfer hydrogenation of nitriles. The ultrathin-modified silica “skin” with 2–3 nm thickness is fabricated by the consecutive hydrolysis of (3-aminopropyl)triethoxysilane and n -propyltriethoxysilane, and the bimetallic catalyst Fe 3 O 4 @PtCu is encapsulated in the coating. The modified catalyst demonstrated significant catalytic efficiency for hydrogenation of benzonitrile to dibenzylamine. The reaction performs 93% conversion and 99% selectivity in “green” solvent H 2 O. Furthermore, the modified silica “skin” encapsulates the PtCu nanoparticles to prevent the leaching of active sites, thus brings excellent catalytic recyclability. More than Fe 3 O 4 @PtCu, the modified silica “skin” is applicable to a diverse range of catalysts, that is, PtCu/SiO 2 , PtCu/Al 2 O 3 , and PtCu/UiO-66, endowing them with additional catalytic activity and selectivity in the hydrogenation of nitriles.
研究领域:
催化
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材料科学
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化学工程
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DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2024
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IF 10.8
Lifang Zhang,Wenting Yuan,Wangchao Zhao,Bo Yang,Xiaoqiao Jiao,Li Zhou,Shiqian Long,Jiwen Xu,Weilin Huang,Chenglin Liu,Guomao Zheng,Huizhong Shen,Jianhuai Ye,Lei Zhu,Tzung-May Fu,Xin Yang,Chen Wang
Carcinogenic nitrosamines have been widely studied due to their risk to human health. However, the universality and evolutionary processes of their generation, particularly concerning their secondary sources, remain unclear at present. We demonstrated through laboratory flow tube experiments that corresponding nitrosamines were generated from heterogeneous reactions of nitrous acid (HONO) with five structurally diverse amines commonly found indoors, including diphenylamine (DPhA), dibenzylamine (DBzA), dioctylamine (DOtA), N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD), and N-phenyl-1-naphthylamine (PANA). The heterogeneous reaction rate constants of DBzA and DOtA with HONO (∼70 ppb) were 1.21 × 10–3 and 2.13 × 10–3 min–1 at 30% relative humidity (RH), resulting in a lifetime of 13.8 and 7.8 h. As compared to higher RH (∼80%), more nitrosamines were produced from the reaction of HONO with surface-sorbed DBzA, DOtA, 6PPD, and PANA at lower RH (30%), with product yields ranging from <0.1% to 0.5%. Furthermore, we observed the formation of nitroso-6PPDs and nitro-6PPDs during room air exposure of 6PPD in a genuine indoor environment, in addition to various other transformation products indicative of reactions of 6PPD with HONO, NOx, and ozone indoors. This study confirmed the universality of the heterogeneous reaction of surface-sorbed amine with HONO as a source of nitrosamines indoors.
研究领域:
环境化学
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室内空气质量
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大气科学
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化学工程
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DOI
PubMed
高影响因子
CHINESE CHEMICAL LETTERS
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2014
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IF 1.178
Ming-Hui He,Mei-Lin Su,Zhao-Hui Yu,Guang-Xue Chen,Zhao-Hua Zeng,Jian-Wen Yang
Benzoylformamide (BFA) derivatives are proposed as new photocaged bases with good solubility in epoxy resin. Initially their structures were confirmed by 1 H NMR, 13 C NMR, and elemental analysis. Next, we detail their thermal stability, solubility behavior, and photolysis products. Furthermore, the model photo-latent anion polymerization (AP) of epoxide system in the presence of BFA-dBA ( N , N -dibenzyl-2-oxo-2-phenylacetamide) as a photocaged base has been investigated, and excellent photopolymerization profile is obtained.
研究领域:
材料科学
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化学
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DOI
高影响因子
Analytical Methods
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2014
·Vol. 6
·期 12
·4228-4233
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IF 1.938
Liqiang Liu,Huang Kuang,Chifang Peng,Libing Wang,Chuanlai Xu
Salbutamol (SAL) is a short-acting β2-adrenergic receptor agonist (β-agonist) forbidden in livestock production. To develop a more sensitive and specific detection method for SAL, a new hapten was synthesized, keeping the structure of benzene ring side of SAL while changing the tert-butyl group structure that SAL shares with other β-agonists. Ten mice were immunized with a SAL hapten–keyhole limpet hemocyanin (KLH) conjugate, and cells were selected within a urine sample at the cell fusion stage. The best monoclonal antibody (Mab) had an IC50 value of 0.31 ng mL−1 in PBST buffer and an IC50 value of 0.19 ng mL−1 in a swine urine sample diluted five times (with a lower B0 value), and had no cross-reactivity with clenbuterol and other β-agonists. These results show that the hapten design was successful and that the Mab can potentially be used in highly sensitive immunoassays for specifically monitoring the illegal use of SAL in real samples.
研究领域:
免疫学
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药物检测
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动物医学
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DOI
高影响因子
Catalysts
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2023
·Vol. 13
·期 5
·799
·
IF 3.9
Tao Wang,Jie Li,Hanwen Yan,Guoliang Zhang,Shifeng Li
Methacrolein (MAL) is an important intermediate extensively used in the manufacture of methyl methacrylate and other materials (polymers and resins). In this study, a series of secondary amines/acids were explored as catalysts for the condensation of formaldehyde and propionaldehyde to prepare MAL. It was found that the structure of the amines and acids directly affected the yield of MAL. The effect of the catalyst was closely related to the nucleophilicity of the amines as well as the steric hindrance effect, while acids also played a role as co-catalysts. Dibutylamine acetate was selected as the catalyst after investigation. The catalytic performance of the system was systematically studied by a series of single-factor experiments, including stirring rate, temperature, reaction time, acid/amine ratio, and the solvent, and the optimized reaction conditions were obtained. In the optimum condition, the yield of MAL was up to 97.3%. Kinetic experiments were performed for the condensation of formaldehyde and propionaldehyde to MAL, and the activation energies, reaction orders, and rate-limiting step of the reaction were determined. The results indicate that the decomposition of the Mannich base is a rate-limiting step.Keywords:methacrolein;aldol condensation;Mannich reaction;kinetics
研究领域:
有机化学
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催化化学
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DOI
高影响因子
LANGMUIR
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2023
·
IF 3.9
Lin Song,Han Jia,Fuling Zhang,Haidong Jia,Yuanbo Wang,Qiuyu Xie,Fangning Fan,Qiang Wang,Shijie Wen
Surfactant-free microemulsions (SFMEs) have been explored extensively to avoid the residual surfactant problem caused by traditional surfactant microemulsions. Many researchers focused on the SFMEs with tertiary amine, which exhibited the typical CO2 response behavior. In this study, the phase diagram of the SFMEs consisting of tripropylamine (TPA), ethanol, and water was readily prepared via the measurements of electrical conductivity. The CO2 response behavior of SFME was confirmed by determination of conductivity and measurement of the average diameter of SFME, which was mainly dependent on the protonation of TPA induced by the additional CO2. The transition of protonated TPA to a more hydrophilic nature from lipophilicity to hydrophilicity should be responsible for the variation of SFME average diameter. In addition, the SFMEs exhibited remarkable solubilizing capacity of crude oil, and three types of SFMEs achieved more than 80% oil removal rate in the washing process of oil sands. It was noted that both oil-in-water and bicontinuous SFMEs could be circularly utilized at least three times with a relatively high oil removal rate (%). Our work provided the insight perspective on the mechanism of SFMEs with a CO2 response behavior.
研究领域:
化学工程
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环境科学
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DOI
PubMed
高影响因子
Polymers
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2023
·Vol. 15
·期 20
·4145
·
IF 5
Guichuan Xu,Zhuhan Wang,Yefeng Chen,Li Qin,Limei Zhou
Porous carbon nitride/bismuth oxychloride (PCN/BiOCl-x) polymer-based heterojunction photocatalysts were successfully synthesized via a simple in situ hydrothermal method. A PCN/BiOCl heterojunction with rich chlorine defects is prepared by adjusting the chlorine content of the BiOCl unit in the heterojunction by changing the solvent. The as-prepared catalysts were characterized via BET, SEM, TEM, XRD, XPS and optical testing, and they were used for a photocatalytic amine oxidation reaction. The results indicated that the catalytic performance of the PCN/BiOCl heterojunction was significantly enhanced due to the rich chlorine vacancies in the samples. The enhanced catalytic activity may be attributed to the Z-scheme heterojunction, abundant chlorine defects and large specific surface area. At the same time, the catalyst circulation experiment shows that the PCN/BiOCl heterojunction has good circulation performance.Keywords:chlorine vacancy;Z-scheme heterojunction;amine oxidation;polymer-based;photocatalysis
研究领域:
材料科学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
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