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。     

快速毛细管气相色谱分析白酒中的香味成分

本文建立了快速毛细管气相色谱法,在10 min内分离了白酒中的香味成分,并对其中的醇、醛、酸、酯进行定性分析,对主要呈味成分己酸乙酯进行定量分析,方法重复性好,回收率较高。与常规毛细管色谱法相比,快速毛细管气相色谱法有效地缩短了分析时间,提高了白酒的分析效率。     

毛细管柱直接进样法测定白酒香味组分的研究

直接注入白酒以准确测定微量香味组分含量是近年来研究白酒香味的首选技术,围绕所选的３种柱型,对色谱分离条件、气相色谱／质谱（ＧＣ／ＭＳ）定性及采用３个内标物的定量方法作了较详细的探讨,列出了可供定量的６８个组分名称,并对３种毛细管柱的应用特性作了比较。     

粘鼠胶的成分分析

使用各种分离、分析手段剖析粘鼠胶的组成，首先使用适当溶剂，通过分级沉淀分离粘鼠胶的各组分。然后用傅立叶变换红外光谱仪、核磁共振波谱仪对分离后的组分进行结构鉴定。     

气相色谱/质谱研究中国干红葡萄酒香味成分

１　　引　　　　言葡萄酒是风行世界的饮料酒。其酒精度低且含有较多的果酸,是一种具有美容作用的酒饮料。近年来中国葡萄酒工业发展较快,但由于葡萄酒水分多、糖度高,呈味物质复杂,且葡萄产地,气候、生产工艺、储存条件均会影响其风味,给生产控制带来了一些困难,本文以ＧＣ／ＭＳ研究中国干红葡萄酒香味成分,４８种成分被确定。２　　实验部分２．１　　仪器　　ＨＰ５９７３气相色谱质谱联用仪（ＧＣ／ＭＳ）,ＨＰ　ＩＮＮＯＷＡＸ　３０　ｍ×０．２５　ｍｍ×０．２５　μｍ）毛细管柱,ＮＩＳＴ质谱谱库。２．２　　ＧＣ／…     

中药党参挥发性成分分析

采用“乙醚冷浸－索氏提取－水蒸汽蒸馏”方法对党参中挥发性成分进行提取,用ＧＣ分离,加标定性和ＧＣ－ＭＳ联用鉴定其组分。分离出２６８种化合物,鉴定出６４种。     

基于稀土离子颜色特征识别的组分含量检测方法

针对稀土离子具有特征颜色的P507-RECL3萃取分离体系,给出一种基于稀土离子颜色特征识别的组分含量检测方法。首先,通过对稀土离子颜色特征随组分含量的不同而呈现不同变化的分析,表明稀土组分含量与其颜色特征之间存在一定关系。为定量描述组分含量与颜色特征之间的关系,提取H分量直方图作为其颜色特征,并计算其一阶矩统计值,使抽象的颜色特征数值化,最后,利用最小二乘法拟合组分含量与H分量一阶矩统计值之间的函数关系,建立了分段拟合模型,并对模型的有效性进行了验证。结果表明,在单一组分占主要含量时,相对误差能控制在2%以内,具有较高的检测精度,为稀土组分含量的在线检测提供一种新的途径。     

快速气相色谱法分析白酒中的香味组分

中国的传统白酒里含有多种香味组分,包括醇类、醛类、酸类和酯类,它们的比率决定着白酒的香型和品质。这些组分可以使用气相色谱仪进行很好的分析并定性和定量。为了缩短分析时间,建立了一种快速检测白酒中香味组分的气相色谱法。采用该方法,用20 m×0.1 mm×0.1 μm的熔融石英毛细管柱在12 min之内完成了对白酒中香味组分的分析,分析时间只是传统色谱方法的三分之一。该方法的重现性良好。     

啤酒花酊挥发性香味成分的GC-MS分析

利用连续液－液提取技术分离啤酒花酊的香味成分,用ＧＣ－ＭＳ和双柱复检法对啤酒花酊的挥发性化学成分进行了定性分析,质谱共鉴定出４４种化合物,其主成分为４,４－ｄｉｍｉｔｈｙ１－３,５－ｄｉｏｘａｈｅｘａｌｄｏｘｉｎ－２,６－ｄｉｏｎｅ和３－甲基丁酸。对主要成分进行定量和重现性比较,结果令人满意。该法简便、快速,为食品工业添加剂的质量监控和常规分析提供参考。     

白千层挥发油化学成分分析

用毛细管气相色谱、气相色谱－ 质谱－ 计算机分析技术, 对植物白千层枝叶挥发油化学成分进行了分析研究, 从这种植物挥发油中分离出８０ 个以上的组分, 确认了其中的３５ 种成分, 所鉴定的组分占挥发油色谱总峰面积的９０ ％ 以上。     

Fast GC analysis of major volatile compounds in distilled alcoholic beverages: Optimisation of injection and chromatographic conditions

The principal secondary flavour compounds in distilled spirits can be successfully quantified by split injection to a 0.15 mm internal diameter (I.D.) capillary column. Initial conditions for split ratio, gas velocity, initial oven temperature and oven ramp rate are given by method translation from a similar method on a standard 0.25 mm internal diameter column with the same phase. These parameters were then investigated in an experimental design comprising a series of experiments in which the responses were the resolution of two critical peak pairs, the analysis time and the limit of quantification (LOQ) of the eight major compounds. The LOQ is the concentration corresponding to a signal 10 times greater than the noise. The experiments were replicated at two different concentration levels, which encompassed the natural levels of the compounds of interest found in distilled spirits. From the chemometric evaluation of these data, a validated model was constructed, which allowed the prediction of conditions for optimum chromatographic analysis. Three additional concentration levels were then added to the model to establish linearity, repeatability and sensitivity. Modern gas chromatographic hardware allows the use of these narrow-bore capillary columns for routine use without operational difficulties. Major advantages are a substantial decrease in analysis time allowing high throughput processing of samples.     

天然香料的超临界CO_2流体萃取

对天然产品的需求导致人们对超临界CO2流体萃取的极大兴趣。本文综述了超临界CO2流体萃取在天然香料中的研究和应用进展并讨论了它与传统分离方法相比较时的优点。     

Characterization and identification of a "mystery" oil spill from Quebec (1999)

This paper describes a case study in which advanced chemical fingerprinting and data interpretation techniques were used to characterize the chemical compositions and determine the source of an unknown spilled oil from Quebec. On 28 February 1999, significant amounts of oil was reported on the river banks of St. Laurence River in front of a company named "Thermex" (in a town - Beauharnois, Quebec, about 50 km northwest of Montreal). The spilled oil was suspected to be released from a nearby factory. In response to this specific site investigation needs, a tiered analytical approach using GC-MS and GC-flame ionization detection was applied. A variety of diagnostic ratios of "source-specific marker" compounds, in particular isomers of biomarkers and alkylated series of polycyclic aromatic hydrocarbons within the same alkylation groups, were determined and analyzed. The hydrocarbon analysis results reveal the following: (1) the spilled oil is very "specific", and is significantly different from most crude oils in chemical composition; (2) the oil in samples come from the same source, however, the spill sample 2569 was identified to contain a small amount (approximately 10%) of diesel; (3) the spilled oil was relatively "fresh", its chemical composition has not undergone significant alteration yet; (4) the spilled oil showed unusually high concentration of the US Environmental Protection Agency priority polycyclic aromatic hydrocarbons (PAHs). The "Pyrogenic Index" values were determined to be as high as 0.11-0.13, significantly higher than crude oils (<0.010) and heavy Bunker type fuels (0.015-0.060). This indicates significant contribution of PAH composition from pyrogenic components; (5) biomarkers were also detected, but their concentrations were unusually low in comparison to most crude oils.     

Capillary headspace - gas chromatography for the characterization of the flavour of fresh vegetables

Summary Static headspace sampling combined with gas chromatography using open-tubular (capillary) columns for the characterization of the flavour of raw vegetables and some vegetable products is described. In order to avoid alteration of the composition of the volatiles, the sample was thermostated for a short time only. Although equilibrium between vapour and sample was not established the reproducibility of such conditions is demonstrated. Typical chromatograms are given; the most characteristic compounds present were identified by mass spectrometry. Enlarged text of a poster presented at the Twelfth International symposium on Capillary Chromatography, September 11–14, 1990, Kobe, Japan     

Determination of alkenylbenzenes and related flavour compounds in food samples by on-column preconcentration-capillary liquid chromatography

A new, simple and versatile method is presented for the determination of different concentration levels of alkenylbenzenes (eugenol, isoeugenol, eugenol methyl ether, myristicin, anethole and estragole) and the related flavour compounds (coumarin and pulegone) in food samples. The method involves the use of a stationary phase (capillary column) for the enrichment with appropriate elution. After the sample had completely passed through the capillary column the eluent was changed and the separation/detection was achieved. Excellent linearity was obtained under the proposed conditions for a direct determination method and a method including on-line preconcentration. The limits of detection were in the ranges 97–148 and 9.5–14.2 ng/mL, respectively. Evidence for a matrix effect was not found and recoveries between 92 and 110% were obtained. The precision of the method, expressed as relative standard deviation values, was below 5% in all cases. The applicability of this methodology was tested by analyzing synthetic and real food samples.     

Flavouring and odorant thiols from renewable natural resources by In-catalysed hydrothioacetylation and lipase-catalysed solvolysis

A chemoenzymatic access to thiol compounds, including ethyl 3-thiobutanoate, 3-thio-p-menthene and 8-thio-p-menthan-2-one, three compounds of interest in flavour and fragrance chemistry presenting various fruity notes, is proposed. It involves an indium(III)-catalysed hydrothioacetylation of renewable precursors followed by an enzymatic solvolysis of the obtained thioesters by lipases in aqueous or organic solvents.     

Polysaccharides of Algae 71*. Polysaccharides of the Pacific brown alga <Emphasis Type="Italic">Alaria marginata</Emphasis>

The polysaccharide composition in sporophylls of the brown alga Alaria marginata enriched with laminaran and sulfated polysaccharides was studied. It was shown that laminaran molecules had an average degree of polymerization about 30 and consisted mainly of 3-linked β-D-glucopyranose residues, having no more than 10% of 1→6 linkages. The majority of chains (about 60%) were terminated at "reducing" end by mannitol residue. Alginic acid of sporophylls contained mannuronic (M) and guluronic (G) acids residues distributed along the linear polymer molecules as MM, MG, and GG blocks at a ratio of 4: 1: 1. Fucoidan was found to be composed of fucose, galactose, and sulfate as the major constituents, while xylose, mannose, glucuronic acid, and acetate were the minor components. It was shown that fucoidan contained two major components: fucan sulfate, molecules of which are built up of 3-linked fucopyranose residues with branches and sulfate groups at different positions, and fucogalactan, also containing chains of 3-linked fucopyranose residues with branches at positions 4 together with highly branched galactan chains terminated by fucose residues. The fucoidan contained also sulfated glucuronomannan and sulfated glucuronan as minor components.     

Effect of maturation in small oak casks on the volatility of red wine aroma compounds

Wood maturation of red wine produces complex interactions between oak extracted compounds and pre-existing components in wine. Wood contributes with some aroma volatiles; but the whole volatile fraction, including the volatiles extracted from grape or produced during fermentation, could be involved in interactions with the non-volatile fraction. Samples of red wine with increasing time of wood contact, matured in 25 l casks of new American oak, were analysed on their volatile composition both in solution and headspace, and phenolic components. There was an increase of acetic acid and acetate esters as the time of wood contact increased. On the other hand, ethyl esters decreased as the time in wood increased. Some volatiles showed different behaviour when comparing their relationship between headspace and solution from two different casks, even though they were treated as replicates. This different evolution among casks was also consistent with different evolution of phenolic compounds, suggesting that there was an interaction among the volatile fraction and phenolic components.     

Headspace methods for volatile components of grapefruit juice

Summary Static headspace, dynamic headspace (DHS) and strip/trap methods were evaluated with grapefruit juice volatiles and an aqueous model system of selected grapefruit volatile flavour components, to select the best method for the isolation of volatile components for subsequent GC analysis.Recoveries were calculated for these methods in the concentration range 0.01–10gml^–1 and compared. Analyte trapping followed by thermal desorption was performed with Tenax TA traps which gave good results in terms of very low blanks. DHS analysis gave the best results in terms of recovery efficiency and, if adequately combined with a simultaneous steam distillation/solvent extraction method, is the most suitable for the qualitative and quantitative investigation of grapefruit juice volatiles, and it might be extended to other fruit juices or liquid foods.