微流控纸芯片在环境分析检测中的应用

近年来,微流控纸芯片由于低成本、便携化、检测快等优点,在需要快速检测的环境分析领域中展现出了巨大的应用前景.该综述从微流控纸芯片在环境分析中的应用角度,总结归纳了微流控纸芯片在环境分析中的最新研究进展,并展望了其在未来的发展趋势与挑战.论文内容引用150余篇源于科学引文索引(SCI)与中文核心期刊中的相关论文.该综述包...     

大麻中3种酚类成分测定专用固相萃取柱的设计与应用

大麻中的主要成分大麻二酚(CBD)、大麻酚(CBN)和 Δ9-四氢大麻酚(Δ9-THC)的含量决定了其性质和应用.在液相色谱分析中,由于大麻提取液中含有较多杂质,需要净化.该文基于大麻中CBD、CBN和 Δ9-THC的结构特征及样品基质组成,根据中性氧化铝、硅酸镁和石墨化炭黑的不同表面特征,考察了这3种吸附剂对大麻提取...     

新型样品前处理材料在环境污染物分析检测中的研究进展

针对复杂样品的分析和痕量目标物的检测,样品前处理是必不可少的,高效的样品前处理技术不仅可以去除或减小样品基质干扰而且能够实现分析物的富集,提高分析检测的准确性和灵敏度.近年来,固相萃取、磁分散固相萃取、枪头固相萃取、搅拌棒萃取、固相微萃取等高效的样品前处理技术已在环境污染物分析检测中获得广泛关注,萃取效率主要取决于萃取...     

基于非靶向代谢组学的茄梨和红茄梨成熟期果皮代谢产物的差异分析

为了探究西洋梨品种茄梨及其红色芽变红茄梨成熟期果皮代谢产物差异,采用超高效液相色谱-质谱联用技术,对茄梨和红茄梨成熟期果皮进行非靶向代谢组学研究。通过主成分分析和正交偏最小二乘判别分析,构建了多变量统计分析模型,结合模型和变量重要性投影与最大差异倍数值,基于精确质量数、二级碎片以及同位素分布,使用PMDB(Plant Metabolome Database)数据库进行定性,筛选并鉴定出茄梨和红茄梨果皮中显著性变化(P<0.05, VIP(variable importance in project)≥1)的差异代谢物有83种,主要包括酚酸类、黄酮类和氨基酸类物质,涉及类黄酮代谢、氨基酸代谢、苯丙烷类代谢等代谢途径,其中53种物质含量上调,30种物质表达下调。通过KEGG(Kyoto Encyclopedia of Genes and Genomes)数据库进一步对差异代谢物质进行通路富集分析,差异代谢物主要分布在20条代谢途径中,P<0.05的代谢途径有6条,分别是类黄酮生物合成、黄酮和黄酮醇生物合成、苯丙烷生物合成、丁酸酯代谢、苯丙氨酸代谢、酪氨酸代谢。这些差异代谢物的变化可能是导致茄梨和红茄梨果皮色泽不同的原因。该研究从植物代谢组学角度初步揭示了茄梨和红茄梨成熟期果皮的代谢产物差异性。     

氟化共价有机聚合物固相微萃取-高效液相色谱测定水产品中丁香酚类麻醉剂

氟化共价有机聚合物(F-COP)具有较大的比表面积和吸附容量,对丁香酚类化合物具有特异性吸附.该文以2,3,5,6-四氟对二苯甲醛(TFA)和1,3,5-三(4-氨苯基)苯(TAPB)为单体,三氟甲磺酸钪(Sc(OTf)3)为催化剂在室温下快速合成F-COP,并将其作为固相微萃取(SPME)吸附剂,结合高效液相色谱-紫...     

Co3O4 Decorated Ti/TiO2 Nanotubes for Photogenerated Cathodic Protection of 304 Stainless Steel

The Co₃O₄ decorated TiO₂ nanotube arrays(NTAs) coatings are fabricated by the combination of anodization and impregna-ting methods. It is found that the introduction of Co₃O₄ can reduce the diffraction intensity of (101) plane of the TiO₂ and accelerate the separation of photogenerated electron/hole pairs. In addition, the open circuit potential(OCP) and the corrosion potential of 304 stainless steel(304SS) with or without Co₃O₄ decorated TiO₂ NTAs were measured under visible light, which indicated the 304SS coupled with Co₃O₄ decorated TiO₂ NTAs had better anticorrosion performance than that of the 304SS or the 304SS coupled with pure TiO₂ NTAs. The enhancement of the cathodic protection performance of the Co₃O₄ decorated TiO₂ NTAs can be ascribed to the matched energy levels and strong interaction between Co₃O₄ and TiO₂ NTAs, and the improvement of light absorption.     

Microwave-assisted Catalyzed Synthesis and In vitro Bioactivity Evaluation of Benzimidazoles Bearing Phenolic Hydroxyl

An efficient and facile method was introduced for the synthesis of benzimidazoles in this paper. The optimum reaction conditions were determined. A series of benzimidazoles bearing phenolic hydroxyl(2a-2t) were synthesized in moderate to excellent yields starting from differently substituted hydroxyl benzaldehyde and 4-position substituted o-phenylenediamine via nucleophilic addition in the presence of catalyst Na₂S₂O₅ under microwave irradiation condition. Herein, effects of the catalyst, molar ratio of reactants, reaction temperature and solvent were investigated. The optimal reaction condition was determined. The effect of DMF and EtOH solvent on the reaction was compared. The synthesized compounds were characterized by FTIR, HRMS, ¹H NMR and ¹³C NMR spectroscopy. Further, the bacteriostatic activities of the synthesized compounds were evaluated with ciprofloxacin and itraconazole as a positive control, respectively. Compounds 2b, 2n, 2q and 2r exhi-bited some antibacterial activity. The lowest MIC of antibacterial activity of compound 2b was 32 μg/mL. Meanwhile, the luminescence property of compound 2b was studied. The antibacterial activity of compound 2b, along with their good fluorescence performance highlighted the potential of these compounds as lead structures and owned fluorescence trace for further study towards the development of novel drugs and functional mechanisms in living organisms.     

Recent Process of Photo-responsive Materials with Aggregation-induced Emission

The research of photo-responsive materials, with changed absorption and emission under light stimulus, has drawn more and more attention due to their wide applications. However, most of them suffered from the notorious aggregation-caused quenching(ACQ) effect, which often led to the unconspicuous luminescent change in photo-responsive process. To solve this problem, the strategy of combining aggregation-induced emission(AIE) and photochromic properties was utilized, which largely enriched the phenomenon and application of photo-responsive materials. This short review summarized the recent progress of photo-responsive AIE materials with changed UV absorbance or PL phenomenon under UV-irradiation, including the types of molecular structures, internal mechanisms and the practical applications. Also, some outlooks were given on the further exploration of this field at the end of this paper.     

Reactive Dyeing of Electrospun Cellulose Nanofibers by Pad-steam Method

Based on the functional properties of electrospun cellulose nanofibers(CNF), scientists are showing substantial interest to enhance the aesthetic properties. However, the lower color yield has remained a big challenge due to the higher surface area of nanofibers. In this study, we attempted to improve the color yield properties of CNF by the pad-steam dyeing method. Neat CNF was obtained by deacetylation of electrospun cellulose acetate(CA) nanofibers. Three different kinds of reactive dyes were used and pad-steam dyeing parameters were optimized. SEM images revealed smooth morphology with an increase in the average diameter of nanofibers. FTIR results showed no change in the chemical structure after dyeing of CNF. Color fastness results demonstrated excellent ratings for reactive dyes, which indicate good dye fixation properties and no color loss during the washing process. The results confirm that the pad-steam dyeing method can be potentially considered to improve the aesthetic properties of CNF, which can be utilized for functional garments, such as breathable raincoats and disposable face masks.     

Esterification of Oleic Acid to Produce Biodiesel over 12-Tungstophosphoric Acid Anchored Two-dimensional Zeolite

Biodiesel has emerged as a non-toxic, biodegradable, and renewable fuel substitute that can be readily produced via the esterification reaction of free fatty acids. The present work explores the potential of 12-tungstophosphoric acid(TPA) anchored two-dimensional(2D) ITQ-2 zeolite(TPA/ITQ-2) as heterogeneous acid catalysts for biodiesel production. TPA/ITQ-2 material was prepared by swelling, delamination, and subsequent wetness incipient impregnation approach. The prepared catalysts were comprehensively characterized by powder X-ray diffraction, N₂ adsorption/desorption, temperature-programmed desorption of ammonia, flou-rier transform infrared spectroscopy, and transmission electron microscopy. The catalytic activity of TPA/ITQ-2 for biodiesel production was evaluated by the esterification reaction of oleate acid with methanol. Process parameters, such as reactant molar ratio and TPA loading were optimized. Due to the superior mass transfer and adequate stable acid sites, 2D TPA/ITQ-2 showed a higher catalytic activity and a better recyclable stability than the 3D and layered TPA/zeolites. This work will provide new opportunities for the design of 2D zeolite-based acid catalysts for biodiesel production.