超分子溶剂在样品前处理与检测技术中的应用研究进展

随着绿色分析化学概念的提出,新型绿色溶剂的开发和利用成为当前的研究热点.将绿色溶剂替代传统有机溶剂用于样品前处理过程,可以减少对实验人员及环境的危害.超分子溶剂由于两亲物质含量高,萃取分离条件温和,近年来被广泛应用于萃取富集宽极性范围内的目标分析物,兼具萃取和净化的效果.该文介绍了超分子溶剂的形成过程和基本性质,综述了...     

超高效液相色谱-串联四极杆静电场轨道阱高分辨质谱法测定豆类中的硒代蛋氨酸

该研究利用超高效液相色谱-串联四极杆静电场轨道阱高分辨质谱(UHPLC/ESI-Q-Orbitrap)技术,对硒代蛋氨酸(SeMet)的色谱信息、分子离子质荷比和碎裂片段的质荷比进行采集,并对特征离子碎裂途径进行解析,建立了豆类中硒代蛋氨酸的检测方法。样品用三羟甲基氨基甲烷-盐酸(Tris-HCl)缓冲溶液溶解后,涡旋混匀,超声提取,在恒温水浴条件下酶解,离心后取上清液过0.22μm滤膜后上机检测。采用Hypersil GOLD HILIC(50 mm×2.1 mm,1.9μm)色谱柱进行分离,以0.2%(体积分数,下同)甲酸6 mmol/L甲酸铵水溶液和0.2%甲酸6 mmol/L甲酸铵乙腈溶液为流动相梯度洗脱,采用电喷雾正离子模式电离,在全扫描/数据依赖扫描模式(Full MS/dd-MS2)下进行检测,基质匹配标准校正法定量。结果表明,硒代蛋氨酸的基质效应为15.75%,在0.05~0.5 mg/L范围内线性关系良好,相关系数(r²)为0.9976,方法检出限(LOD)为0.015 mg/kg,定量下限(LOQ)为0.05 mg/kg;空白样品在0.1、0.2、0.4 mg/kg 3个加标水平下的平均回收率为77.6%~83.2%,日内相对标准偏差(RSDr)为2.8%~4.8%,日间相对标准偏差(RSD_R)为4.1%~6.5%。将方法应用于实际样品的检测,得富硒黑豆、富硒红豆、富硒绿豆中硒代蛋氨酸的含量分别为0.252、0.163、0.184 mg/kg。该方法具有前处理操作简单、结果准确、重复性好等优点,适用于豆类中硒代蛋氨酸的检测。     

吸光材料-激光解吸附离子化质谱用于化妆品中添加剂的快速分析

化妆品中的添加剂种类繁多,这些物质的加入可提升化妆品的使用效果和保质期限,但过量使用则可能对人体健康造成不良影响.该研究利用吸光材料-激光解吸附离子化质谱(AR-LDI MS)建立了化妆品中添加剂的快速分析方法.利用该法对化妆品中的3-亚苄基樟脑、4-甲基苄亚基樟脑、对羟基苯乙酮和环吡酮进行检测,检出限分别为4、6、4...     

UIO-66热解ZrO2负载CoMoS对4-甲基酚的加氢脱氧性能

以金属有机骨架材料UIO-66热解制备了具有片层簇状结构ZrO₂.UIO-66热解条件影响CoMo S/ZrO₂的晶相、表面原子含量、形貌以及比表面积（可达117.7 m²/g）.随着热解温度升高,ZrO₂晶相呈现由四方相向单斜相的转化,表面Mo含量呈现先减小后增加的趋势,片层结构逐渐变短,而簇状结构则逐渐由蓬松变得致密,比表面积逐渐减小.热解温度为600℃时出现催化剂片层结构的坍塌聚集以及晶相的破坏.当UIO-66热解温度为500℃、热解时间为4 h时,CoMoS/ZrO₂明显出现单斜相,表面Mo原子含量较高,片层结构较均一,此催化剂在4-甲基酚加氢脱氧中显示出较高的活性和对甲苯的选择性,4-甲基酚转化率达100%,甲苯的选择性达82%.     

基于i-motif的生物医学应用纳米系统:pH成像、药物控释和肿瘤诊疗

I-motif作为一种新型pH敏感元件,因其在不同pH条件下可以进行快速的构象转变,以及具有自动化合成、优异的生物相容性和灵活的功能化整合等优点,在生物医学领域引起了广泛的关注和研究热潮.该文介绍了i-motif的基本性能,综述了基于i-motif的纳米系统在细胞pH成像、pH控制的药物释放和pH响应型肿瘤诊疗一体化等...     

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.     

Host-Guest Interactions of Cyclopentanocucurbit[6]uril with Alkyl Imidazolium Hydrochlorides

The host-guest interactions between cyclopentanocucurbit-[6]uril(CyP₆Q[6]) as host and six alkyl imidazolium hydrochloride as guests(g1, g2, g3, g4, g5, and g6) have been studied by various techniques, such as ¹H NMR spectroscopy, isothermal titration calorimetry, mass spectrometry, and single-crystal X-ray diffraction analysis. The experimental results showed that CyP₆Q[6] formed 1:1 inclusion complexes with each of guests g1-g6. The part of the guest entered the cavity of CyP₆Q[6] changes as the alkyl chain increases in length. It can be seen that the length of the alkyl chain plays a key role in determining the mode of host-guest interactions.     

引言

质谱技术兼具灵敏度高、选择性强、分析速度快等优势,是现代分析测试领域的"金标准".质谱聚焦于离子的产生、操控、分离和测量,离子化技术的突破革新推动了质谱技术的跨越发展.近年来,无需复杂样品前处理、可在常压环境下实现直接样品分析的敞开式电离质谱技术成为质谱分析领域备受关注的研究热点.自解吸电喷雾电离和实时直接分析问世以来...     

Multilayer Porous Vanadium Nitride Microsheets Anodes for Highly Stable Na-ion Batteries

Sodiumion batteries(SIBs)have attracted intensive attention as promising alternative to lithium-ionbatteries(LIBs)for large scale energy storage systems because of low cost of sodium,similar energy storage mechanism and the reasonable performance.However,it is still a great challenge to search and design a robust structure of anode materials with excellent cycling stability and high rate capability for SIBs.Herein,multilayer porous vanadium nitride(VN)microsheets are synthesized through a facile and scalable hydrothermal synthesis-nitrogenization strategy as an effective anode material for SIBs.The multilayer porous VN microsheets not only offer more active sites for fast Na+insertion/extraction process and short diffusion pathway,but also effectively buffer the volume change of anode due to more space in the multilayer porous structure.The large proportions of capacitive behavior imply that the Na+charge storage depends on the intercalation pseudocapacitive mechanism.The multilayer porous VN microsheets electrodes manifest excellent cycling stability and rate capability,delivering a discharge capacity of 156.1 mA·h/g at 200 mA/g after 100 cycles,and a discharge capacity of 111.9 mA·h/g at 1.0 A/g even after 2300 cycles with the Coulombic efficiency of nearly 100%.     

以史为鉴——化学科普中的人文素养教育

中国古代历史中蕴含着丰富的化学史资源,对这些资源的挖掘、解读,形成化学科普题材,既是化学教育的需要,也是加强思想政治教育背景下课程思政的现实要求。以寒食散为例,探讨中国古代化学史资源所蕴含的人文素养教育价值,认为化学科普中汲取历史资源,不仅增加了科普的趣味性,有利于向公众普及化学知识,还有助于公众树立正确的世界观和价值观。