酶标仪比色法检测浊米酒中高级醇含量

为探索酶标仪比色法在浊米酒高级醇含量检测中的适用性,该研究建立了酶标仪比色法检测浊米酒中6种高级醇(异丁醇、异戊醇、苯乙醇、正丙醇、正丁醇、己醇)的单一和混合标准曲线,并对比了酶标仪比色法和气相色谱法对浊米酒中高级醇含量的检测效果。结果表明,酶标仪比色法建立的混合标曲在0~0.05 mg线性均较好,单一标曲中正丙醇在0~1 mg线性较差,而苯乙醇和正丁醇在0~0.05 mg线性稍差,并在一定程度上影响其他高级醇检测效果;酶标仪比色法测得FBKL2.8022和FBKL2.8023发酵米酒中6种高级醇的质量浓度分别为408.94 mg/L和230.89 mg/L,其中6种高级醇含量的标准偏差分别为0.06%~3.94%和0.72%~1.58%,酶标仪比色法测定结果高于气相色谱法。该研究使用酶标仪比色法检测发酵米酒中不同高级醇的含量,发现高级醇配比不同会影响标准曲线的线性方程和相关系数,因此需要根据样品检测需求而选择合适配比的标曲进行样品检测分析。     

电石与醇的反应行为

在高压釜中研究了电石与甲醇、乙醇和异丙醇的反应行为及反应温度、反应时间和催化剂对产物的影响,通过设计对比实验,探索了电石与醇的反应途径。结果表明,电石与醇的反应产物包括乙炔、乙烯基醚、醇钙和醇钙分解产生的醇。乙烯基醚的生成途径除了文献报道的电石与醇的直接反应外,还包括电石与醇反应生成醇钙和乙炔、乙炔再与醇反应形成乙烯基醚的两步机理。     

Camphorquinone: a new and efficient oxidant for the preparation of 2-thio-substituted benzothiazoles from alcohols by oxidation-reduction condensation

A convenient one-pot procedure for the preparation of various 2-thio-substituted benzothiazoles from alcohols and benzothiazole-2-thiol utilizing camphorquinone-mediated oxidation-reduction condensation is disclosed. The condensation between benzothiazole-2-thiol and alkyl diphenylphosphinites, generated in situ from alcohols and chlorodiphenylphosphine, proceeded smoothly in the presence of camphorquinone to furnish the corresponding benzothiazoles in good to moderate yields.     

黄酒中高级醇含量控制的研究进展

高级醇是黄酒中主要的风味物质,适量的高级醇能赋予黄酒丰满的口感,增加酒体的协调性.但高级醇过量则会给黄酒带来异杂味并引起较强的致醉性,俗称“上头”,控制黄酒中高级醇含量对提高黄酒的质量显得十分重要.该文在简要论述黄酒发酵过程中高级醇形成途径的基础上,对近年来关于黄酒生产原料、糖化剂、酵母和发酵温度等工艺因素对高级醇含量影响的研究现状作了概述.     

The unusual influence of hetaryl groups on the direct conversion of some secondary alcohols into thiols with Lawesson’s reagent: elucidation of the reaction mechanism

A series of hetaryl-substituted methanols were used for direct conversion into the corresponding thiols by treatment with Lawesson’s reagent in boiling toluene. Unexpectedly, the respective sulfides were formed exclusively. In the case of chiral alcohols, the sulfides were obtained as 1:1-mixtures of meso- and dl-diastereoisomers. In contrast to hetaryl-substituted alcohols, the analogous protocol applied for benzhydryl alcohol led to a mixture of the expected secondary thiol and a bis(diphenylmethyl) trithiophosphonate. Finally, the analogous reactions with ferrocenyl(phenyl)methanol and diferrocenylmethanol, respectively, led to the corresponding thiols in good yield.     

啤酒酵母代谢副产物高级醇的影响因素研究进展

高级醇是啤酒酿造过程中产生的副产物的主要成分,是啤酒的主要香味和口味物质之一。高级醇的生成途径有降解代谢和合成代谢两种。适量的高级醇能赋予啤酒丰满的香味和口味,增加酒体的协调性,但过量存在也是啤酒异杂味的主要来源之一。高级醇含量超过100mg／L会使啤酒口味和受欢迎程度明显降低,啤酒中高级醇含量的标准值为：下面发酵啤酒60～90mg／L;上面发酵啤酒〈100mg／L。高级醇含量主要受酵母菌种、麦汁成分以及发酵工艺条件的影响．因此生产过程应控制好这几个因素。     

信息不对称与高等教育

应用现代信息经济学的信息不对称理论分析了在高等教育活动中存在的各种信息不对称现象及其影响,并对其提出了控制和利用措施。     

Activation of Dioxygen by Cobaloxime and Nitric Oxide for Efficient TEMPO‐Catalyzed Oxidation of Alcohols

The aerobic oxidation of alcohols to their corresponding carbonyl compounds could be efficiently accomplished by using the combination of cobalt nitrate, dimethylglyoxime and 2,2,6,6‐tetramethylpiperidine 1‐oxyl (TEMPO) as a novel catalytic system, and various alcohols including primary and secondary benzylic, allylic and aliphatic alcohols could be quantitatively converted to the corresponding aldehydes or ketones at 70 °C under 0.4 MPa dioxygen pressure in dichloromethane. During the oxidation, the in situ generated cobaloxime and nitric oxide (NO) were responsible for the activation of dioxygen, respectively, thereby, two concerted catalytic routes exist: cobaloxime‐activating‐dioxygen TEMPO‐catalyzed and NO‐activating‐dioxygen TEMPO‐catalyzed aerobic oxidation of alcohols.     

Synthesis and Surface Properties of Disodium Monoalkyl Diphenyl Oxide Disulfonate

Disodium monoalkyl diphenyl oxide disulfonates (MADS) with different carbon chains (C_n‐MADS, n = 8, 12, 16) were synthesized through the steps of alkylation‐sulfonation‐neutralization using fatty alcohols (C₈, C₁₂, C₁₆), diphenyl oxide and fuming sulfuric acid (20 % free SO₃) as reagents. The structures of the products were identified by infrared spectroscopy and electrospray ionization‐mass spectrometry. The surface properties, emulsification, wettability alteration and salinity and hardness tolerance of the products were systematically investigated. The results show that the critical micelle concentration (CMC) of C₈MADS, C₁₂MADS and C₁₆MADS are 7.24 × 10^?3, 1.49 × 10^?3 and 2.09 × 10^?4 mol/L. The surface tensions at the CMC (γ_CMC) of each product are 37.5, 38.9 and 46.8 mN/m. The negative logarithm of the surfactant concentration in the bulk phase required to produce a 20 mN/m reduction in the surface tension of the solvent (pC₂₀) increases with the increase in the alkyl chain length. The emulsifying ability of C₁₂‐MADS is better than C₈‐MADS and C₁₆‐MADS, and the MADS showed less oil‐wet nature. The salinity and hardness tolerance of MADS is much stronger than that of conventional surfactants.