Determination of hydroxypropyl bis (N-hydroxyethyl-p-phenylenediamine) hydrochloride in hair dye products by HPLC and its verification by LC-MS/MSEI北大核心CSCD

A method for the determination of hydroxypropyl bis (N-hydroxyethyl-p-phenylenediamine)hydrochloride in hair dye products by high performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed. The sample was ultrasonically extracted with 50% (V/V) ethanol. Chromatographic separation was carried out on a Waters Symmetry C18 column (250 mm×4.6 mm, 5 µm) by isocratic elution. The mobile phase was 0.02 mol/L ammonium acetate aqueous solution and acetonitrile (84∶16, V/V). The detection wavelength was 258 nm. Quantification was performed by external standard method. Verification for positive samples was performed by LC-MS/MS. The results showed good linearity from 2 mg/L to 200 mg/L, with the correlation coefficients (r) higher than 0.999. The limit of detection (LOD) was 0.003%(w/w), and the limit of quantification (LOQ) was 0.01%(w/w). The average spiked recoveries at three levels in both cream and liquid substrates were from 97.5% to 103.4%, with the relative standard deviations (RSDs) from 1.7% to 3.9%. The method could be used to detect hydroxypropyl bis (N[1]hydroxyethyl-p-phenylenediamine)hydrochloride in hair dye products, which could fill the gap of the current standard. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

模拟空间原子氧辐照下X射线光电子能谱仪的原位表征功能开发

对现有的X射线光电子能谱仪进行功能开发,在不改变仪器工作原理、不影响现有功能的前提下,将研制的空间交变温度原子氧辐照装置集成到其快速进样室,重点解决集群结构的匹配和性能兼容问题,实现模拟空间交变温度原子氧辐照环境下材料的原位表征功能.采用Kapton膜的质量损失方法测试空间交变温度原子氧辐照装置的原子氧通量密度,氧气流量、偏压和微波电流均对原子氧通量密度有较大影响.系统测试表明,原子氧辐照使WS 2薄膜表面发生了严重氧化,影响了薄膜的化学组成.不同温度原子氧辐照导致了不可忽略的化学组成与结构的差异.     

掺杂型碳量子点的制备及其在重金属离子检测中的应用

碳量子点(CQDs)具有独特的荧光性质、制备原料来源广泛、合成过程绿色简便、水溶性和生物相容性良好等优点，因而受到广泛关注。CQDs与特定的重金属离子结合后，荧光强度会出现不同程度的增强或减弱，基于此可实现重金属离子的荧光检测。然而，传统的CQDs受限于自身荧光强度不高以及在重金属离子检测中的灵敏度与选择性较差等不足，应用效果并不理想。对CQDs进行杂原子掺杂可调节CQDs中碳原子的电荷密度和自旋密度，提供更多的活性位点，丰富CQDs的能级结构，从而提升其荧光强度。此外，杂原子掺杂可为CQDs引入丰富的官能团，构建易与重金属离子结合的功能界面，从而提高荧光检测的灵敏度。本文综述了近年来氮、硫、磷、锌和铜等原子掺杂CQDs的制备及在重金属离子检测中的研究进展，分析了原子掺杂对CQDs荧光检测性能的影响、原子掺杂CQDs的检测机理、检测应用效果，并展望了其未来的发展方向。     

B3N3H6…CO复合物中弱相互作用竞争的理论研究

本文在MP2/aug-cc-pVTZ水平下对一氧化碳(CO)和环硼氮烷(B₃N₃H₆)之间的弱相互作用进行理论研究，得到6种稳定的B₃N₃H₆…CO复合物结构。B₃N₃H₆…CO复合物中存在N—H…C/O氢键以及π…π、lp…π相互作用，其中含N—H…C氢键复合物的相互作用能(ΔE)最大，为-1.42 kcal·mol^-1。系统的理论计算结果表明π…π相互作用和N—H…C/O氢键可以成功地与lp…π相互作用竞争。取代基效应结果显示，B₃N₃X₃H₃(X=-NH₂)…CO、B₃N₃H₆…CO、B₃N₃X₃H₃(X...