气相色谱-负化学源质谱法测定禽蛋及蛋制品中氟虫腈及其代谢物

建立了气相色谱-负化学源质谱联用技术(GC-NCI-MS)测定禽蛋及蛋制品中氟虫腈及其3种代谢物残留量的方法。样品经乙腈提取,分散固相萃取技术QuEChERS净化,采用基质校正曲线外标法定量。在0.005~0.10mg/L范围内氟虫腈及其3种代谢物均呈现良好的线性关系,所有目标物的定量限均在0.025~0.10μg/kg范围内,均能满足国内外的限量要求。在0.1、2.0、4.0、20.0μg/kg 4个添加水平下,氟虫腈及其3种代谢物的平均回收率均处于87.0%~99.3%,RSD均≤12.7%,说明该法有较高的准确度和较好的稳定性。综上所述,该法灵敏度、准确度较高,精密度较好,可用于禽蛋及蛋制品中氟虫腈及其代谢物残留量的测定。     

15N NMR spectral parameters of compounds of the N-methylpyrazole series

The¹⁵N NMR chemical shifts and¹⁵N-¹H SSCCs are presented for substituted N-methylpyrazoles with substituents such as CH₃, NO₂, Br, Cl, NH₂, O=CNH₂, O=CPh, and COOH at the carbon atoms. The¹⁵N chemical shifts of the cyclic atoms of nitrogen and the nitro groups are discussed as well as the geminal and vicinal SSCCs of the ring nitrogen atoms with the hydrogen atoms of the CH and CH₃ fragments.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117334 Moscow. D. I. Mendeleev Chemico-Technological Institute, Moscow, Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2554–2561, November, 1992.     

Reaktionen cyclischer Oxalylverbindungen, 34. Mitt.: Synthese von Dibenzoylacet-N-carboxyalkylamiden und semiempirische Rechnungen zur Keto-Enol Tautomerie

Summary 4-Benzoyl-5-phenylfuran-2,3-dione (1) and the urethanes2 combine under loss of carbon monoxide yielding the open chain dibenzoylacetic acid derivatives3 and4. 3a, b only can be cyclized to the oxazinone5. The keto-enole tautomerism3 4 is further investigated with aid of semiempirical quantum chemical calculations, based upon the molecular geometry of3a, deduced from an X-ray study.

Frau Univ. Prof. Dr. Helga Wittmann mit den besten Wünschen zum 70. Geburtstag gewidmet.     

Conformation of BEDT-TTF molecules in the crystal

Based on comparison of low-temperature x-ray diffraction data for BEDT-TTF salts and quantum chemical MNDO calculations, we have shown that the most energetically favorable conformation of the BEDT-TTF molecule is not realized in the crystal. A local energy minimum 0.035 eV above the ground state corresponds to the conformation detected in the crystal. The x-ray diffraction data and the MNDO results suggest weak participation of the heteroatoms of the six-membered rings in the conjugation with the -system of the TTF-fragment in the BEDT-TTF and BEDO-TTF molecules.Institute of Chemical Physics at Chernogolovka, Russian Academy of Sciences, Chernogolovka 142432. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 890–894, April, 1992.     

明胶层中的扩散和反应的动力学研究——(Ⅴ)油溶性成色剂的偶合反应的动力学

研究了明胶层中油溶性成色剂油珠的偶合反应动力学。通过实验和数值模拟的比较证明:在明胶层中油溶性成色剂(C-1)油珠与彩色显影剂CD-4的氧化产物的偶合反应主要是发生在油珠-明胶水溶液的界面上。偶合反应速度与油珠大小、比速率常数、成色剂在油相中的浓度以及QDI的扩散系数有关。并且得到C-1成色剂油珠的比速率常数、CD-4氧化产物的扩散系数以及QDI和生成的染料在明胶层中的时空分布。同时观察到温度对偶合反应动力学的影响。     

Wet-Chemically Prepared Porphyrin Layers on Rutile TiO2(110)

Porphyrins are large organic molecules that are interesting for different applications, such as photovoltaic cells, gas sensors, or in catalysis. For many of these applications, the interactions between adsorbed molecules and surfaces play a crucial role. Studies of porphyrins on surfaces typically fall into one of two groups: (1) evaporation onto well-defined single-crystal surfaces under well-controlled ultrahigh vacuum conditions or (2) more application-oriented wet chemical deposition onto less well-defined high surface area surfaces under ambient conditions. In this study, we will investigate the wet chemical deposition of 5-(monocarboxyphenyl)-10,15,20-triphenylporphyrin (MCTPP) on well-defined rutile TiO₂(110) single crystals under ambient conditions. Prior to deposition, the TiO₂(110) crystals were also cleaned wet-chemically under ambient conditions, meaning none of the preparation steps were done in ultrahigh vacuum. However, after each preparation step, the surfaces were characterized in ultrahigh vacuum with X-ray photoelectron spectroscopy (XPS) and the result was compared with porphyrin layers prepared in ultrahigh vacuum (UHV) by evaporation. The differences of both preparations when exposed to zinc ion solutions will also be discussed.     

回归知识本原 构建生命课堂——以“常见物质的检验”为例

以“常见物质的检验”的教学为例,运用化学史料帮助学生自主建构知识体系,促进学生追寻知识本原,实现思维进阶,发展核心素养,并阐述运用化学史料构建高中化学生命课堂的实施策略。     

化工原理问题导向式线上教学的探索与实践*

以化学制药专科专业化工原理课程为例,阐述问题导向式线上教学的课程设计思路及框架,探索由被动教到主动学的线上教学途径。通过对“流体流动与输送单元”的教学设计,从课前、课中和课后论述了以“问题”为中心的线上教学过程和实施情况,并说明了线上授课的教学效果。     

基于洗涤品生产的化工实训课程设计*

为适应地方院校应用型转型发展的要求,结合化工专业特色,设计了基于洗涤品生产的校内化工实训课程。该课程内容丰富、可操作性强。内容涵盖了配方设计、小试实验、生产操作、产品罐装、性能测试、安全教育等环节。课程采用教、学、做、产一体化的教学模式,运行效果显著,可激发学生的学习兴趣,培养学生的科研思维与实践创新能力。