酱香型酒香气成分研究：3.珍酒,茅台酒前香成分的分离及气相色谱…

用Ｎ２吹扫－冷凝方法分离、收集珍酒、茅台酒的前香。收集液经过感官评定，确认为珍酒、茅台酒的前香。用气相色谱／质谱联用方法研究它们的化学组成。鉴定了１２种化合物，并测定了它们的相对含量。     

酱香型酒香气成分研究：1.珍酒,茅台酒空杯香分离及官能色谱探索

本文系统地研究了酱香型酒主体香的分离方法，摸索出“溶剂萃取－自然挥发－溶解”的酱香型酒空杯香的分离方法，首次从珍酒、茅台酒中分离出典型的空杯香。用在线色谱闻香系统研究了酱香型酒空杯香的化学成分，同时进行色谱测定及嗅闻。结果表明，空杯香是多种成分构成的复合香。     

酱香型珍酒香气成分的GC/MS分析

对酱香型珍酒进行了化学处理,分类收集组分,将各组分用GC—MS联用法进行分离与定性定量测定。分离出200多个色谱峰,鉴定出了4个化合物。并平行地进行了与茅台酒的对比分析。结果表明此两种酒的主要组分一致,含量接近。     

GC/MS SIM法快速测定酒中的游离脂肪酸

本文介绍一种简单、快速、灵敏、直接分析酒中游离脂肪酸的测定方法。用涂有OV-17熔融石英毛细管柱。选择游离脂肪酸质谱图中的基峰离子m/z 60进行SIM检测。定量测定了茅台酒、珍酒及鸭溪窖酒中十二种游离脂肪酸。     

酱香型酒香气成分研究：2.珍酒,茅台酒空杯香成分的GC／MS分析

用色质联用（ＧＣ／ＭＳ）法测定酱香型酒空杯香的化学成分，鉴定出１３种化合物，并测定了它们的相对含量，其中以十六酸乙酯、油酸乙酯、亚油酸乙酯为主。     

气相色谱-质谱法分析牛蒡酒香气成分

用乙醚提取，以气相色谱-质谱法分析了牛蒡酒香气的成分，从牛蒡酒中共分离鉴定出36种成分，其中主要成分是乙酸乙酯、已酸、异戊醇，它们约占总量的69%。牛蒡酒中异戊醇与异丁醇的比例高达60：1，表明该酒品质优良。     

钢都酒的香味成分分析

通过对钢都酒进行化学处理,分类收集组分,采用GC-MS联用技术对各组分进行分离与定性定量测定,分离并鉴定出35个化合物,并确定了酒的香型。     

气相色谱-质谱指纹图谱在鉴别贵州茅台酒中的应用

应用气相色谱-质谱(GC-MS)建立了贵州茅台酒的指纹图谱,确证了贵州茅台酒中35种特征组分,并采用浙江大学的中药指纹图谱相似度计算软件对样品图谱之间的相似度进行了评价和鉴别。方法的精密度及重复性良好。研究考察了38个批次贵州茅台酒、5种由贵州茅台酒股份有限公司生产的酱香型系列白酒以及12种由其他厂家生产的白酒的指纹图谱与贵州茅台酒指纹图谱模板的相似度。结果表明,通过酒的特征组分比较和基于“夹角余弦法”的指纹图谱相似度分析,可以区分贵州茅台酒和其他不同酒精度、不同香型的白酒。所建立的方法为贵州茅台酒的真伪鉴定提供了技术储备。     

气相色谱法测定法国干邑酒中非酒精成分

法国干邑酒是一种葡萄蒸馏酒 ,蒸馏酒经过在橡木桶中陈酿一定的时间 ,然后再用不同酒龄的酒勾兑成具有独特风格的酒饮料。它与我国白酒酿造工艺的最主要区别就是在橡木桶中的陈酿。也正是由于这种陈酿 ,让蒸馏酒经过对橡木的浸出、自身的氧化及水解等过程 ,蒸馏酒的非酒精成分发生了变化 ,成为具有花香和果香、酒质醇和的干邑酒 [1] 。因此干邑酒的非酒精成分的检验在干邑酒的化学分析中也就占有特别的意义。干邑酒的非酒精成分包括甲醇、醛类、酯类、高级醇。其中醛类包括乙醛、异丁醛、乙缩醛、糠醛 ;酯类包括甲酸乙酯、乙酸乙酯、丁酸乙…     

论冻酒

烧酒指的是用蒸馏方法而得到的乙醇浓度较高的酒,其历史已有多人考证。在酒的历史上与烧酒相对应的还有一类冻酒,本文要指出,冻酒应是用冷冻除水法而得到的乙醇浓度较高的酒。     

Detection of Paratuberculosis in Dairy Herds by Analyzing the Scent of Feces,Alveolar Gas,and Stable Air

Paratuberculosis is an important disease of ruminants caused by Mycobacterium avium ssp. paratuberculosis (MAP). Early detection is crucial for successful infection control, but available diagnostic tests are still dissatisfying. Methods allowing a rapid, economic, and reliable identification of animals or herds affected by MAP are urgently required. This explorative study evaluated the potential of volatile organic compounds (VOCs) to discriminate between cattle with and without MAP infections. Headspaces above fecal samples and alveolar fractions of exhaled breath of 77 cows from eight farms with defined MAP status were analyzed in addition to stable air samples. VOCs were identified by GC–MS and quantified against reference substances. To discriminate MAP-positive from MAP-negative samples, VOC feature selection and random forest classification were performed. Classification models, generated for each biological specimen, were evaluated using repeated cross-validation. The robustness of the results was tested by predicting samples of two different sampling days. For MAP classification, the different biological matrices emitted diagnostically relevant VOCs of a unique but partly overlapping pattern (fecal headspace: 19, alveolar gas: 11, stable air: 4–5). Chemically, relevant compounds belonged to hydrocarbons, ketones, alcohols, furans, and aldehydes. Comparing the different biological specimens, VOC analysis in fecal headspace proved to be most reproducible, discriminatory, and highly predictive.     

Conformationally Controlled Odor Perception in ‘Steroid-type’ Scent Molecules

A series of compounds possessing a ‘Steroid-type’ scent and related to 4-(4′-t-butylcyclohexyl)-4-methyl-2-pentanones ( 1 and 2 ) has been synthesized. The odor of these compounds has been found to be dependent on their conformation; only when the molecule can assume a steroid-like shape there is an interaction with the odor chemoreceptor.     

Amber‐Woody Scent: Alcohols with Divergent Structure Present Common Olfactory Characteristics and Sharp Enantiomer Differentiation

Only one out of the four possible trans isomers of the important perfumery alcohol Norlimbanol^® ( 1 ) possesses a very strong amber‐woody smell, the isomer 1A with (1′R,3S,6′S) absolute configuration. Its enantiomer 1B is almost odorless and devoid of amber‐woody character, whereas the diastereoisomers 1C and 1D are considerably weaker and perceptible only by the most‐sensitive persons. The same is true for a whole series of perceptual analogs of 1 , including β‐alkoxy alcohols. These ethers belong to two structural classes: [(2,2,6‐trimethylcyclohexyl)oxy]‐ (see 3, 4 , and 16 ) or {[2‐(tert‐butyl)cyclohexyl]oxy}alkan‐2‐ol derivatives (see 19 and 20 ; Table). A superimposition model allowing for good overlap of the respective hydroxylated side chains offers a tentative explanation for the shared perceptual characteristics of the two classes (Fig. 5). The lipophilic cyclohexane moieties present only a minimal overlap in this model, suggesting that quite larger molecules might possess the same smell. (S)‐Configured β‐alkoxy alcohols can conveniently be obtained on a larger scale by enantioselective reduction of the corresponding ketones (Scheme 9).     

Properties of the methyl cellulose-polyvinylpyrrolidone binary system in solution and in the solid state

Rheological properties of dilute and moderately concentrated aqueous solutions of methyl cellulose-polyvinylpyrrolidone blends, as well as the conditions of gelation in them, were studied. Films were obtained from solutions of the polymer blends, and their physicomechanical properties were examined. The range of the compositions corresponding to thermodynamic compatibility of methyl cellulose with polyvinylpyrrolidone was identified by the solvent vapor sorption method and by thermomechanical examinations of the films.     

Synthesis of aldehydes and nitriles in the 5-hydroxyindole series

A preparative method for the synthesis of previously inaccessible 3-formyl-5-hydroxyindole derivatives by Vilsmeier formylation of 5-acetoxyindoles is proposed. 5-Hydroxyindole-3-carboxylic acid nitriles and their 4-dimethylamino-methyl derivatives were obtained from 3-formyl-5-hydroxyindoles through their oximes.     

Chemical and structural transformations in chitosan films in the course of storage

Changes in the functional composition of chitosan films in the course of storage under ambient conditions were examined by conductometric titration and IR spectroscopy. The deformation-strength and thermal properties of the films were studied, and their supramolecular structure was analyzed by X-ray diffraction.     

The use of selected acrylate and acrylamide-based surfmers and polysoaps in the emulsion polymerization of styrene

Polymerizable surfactants (surfmers) 12-acryloyloxy-dodecanoic acid and 11-acrylamidoundecanoic acid and their respective sodium salts were prepared and then polymerized to form their corresponding oligomers using reversible addition-fragmentation chain transfer (RAFT). Different concentrations of both the surfmers, their sodium salts, and their RAFT oligomers were used as polysoaps in the emulsion polymerization of styrene. Stabilities of the pre-emulsions before polymerization were determined and compared. After polymerization, particle sizes and polydispersities of the resulting polystyrene latices were determined. Sodium dodecyl sulfate (SDS) was used as a reference surfactant to compare the particle sizes and stabilities of the pre-emulsions prepared using surfmers and polymeric surfactants (polysoaps) as particle stabilizers. Emulsion polymerization of styrene using these surfmers and polysoaps all led to latices which were stable for a period of more than six months, as indicated by constant particle sizes, whereas latices prepared using the conventional surfactant, SDS, were not as stable.     

Artifacts in the determination of intravenous anesthetics by gas chromatography-mass spectrometry: Tramadol, the correlation between the structures of metabolites and impurity substances

The simultaneous determination of preparations used for multicomponent intravenous anesthesia (Promedol, tramadol, ketamine, diazepam, Thiopental, and phentanyl) and of their metabolites in blood and urine of surgical patients by chromatography-mass spectrometry was considered. Artifacts due to the Chromatographie interference of various preparations and their metabolites were revealed. The lability of the anesthetics and their metabolites in the course of sample preparation and analysis by gas chromatography (GC) was examined. The degradation products of the test preparations responsible for the generation of false positive results were found. Phentanyl, Promedol, ketamine, tramadol, Thiopental, diazepam, and their metabolites excreted with urine in the free forms were determined in the whole blood and urine of surgical patients. Bound forms of metabolites and the initial medicinal preparations excreted as complexes with glucuronic acid and other acids were also determined in urine. Metabolites and impurity substances in the intravenous anesthetics with similar mass spectra and retention times were distinguished. Methodological recommendations concerning the analysis of difficult-to-separate (by capillary gas chromatography) pairs of substances used for intravenous anesthesia and their metabolites are given. The following pairs of components are difficult to separate: Norpromedol-2-methylamino-5-chlorobenzophenon (a product of diazepam hydrolysis), norketamine-Promedol, and anhydrotramadol (a GC artifact)-ketamine. The cumulation of an impurity substance from the tramadol preparation, identified by us as epoxytramadol, in the body was examined.     

Synthesis and properties of the chiral oligonaphthalenes

Helical oligonaphthalenes were constructed by bottom-up synthesis (repeating dimerization reactions), their absolute configurations were determined by an exciton chirality method and their functions, such as energy transfer, are also reported.