油茶壳高品位资源化利用的Py-GC/MS分析

采用Py-GC/MS联机技术研究油茶壳高品位资源化的利用.新鲜油茶壳经冷冻干燥除水后,于590 ℃的He气流中进行热解,然后对热解产物进行GC/MS联机分析,采用色谱峰面积归一化法计算各组分的相对含量,并鉴定出46个化合物.分析结果表明,油茶壳热解产物富含名贵生物医药、名贵香料成分,副产物不仅可用于高档化妆品和护肤品,还可用于生物能源以及食品、染料、工业溶剂等的原料.     

TGA和Py-GC/MS研究琥珀酸单薄荷酯的热失重和热裂解行为

应用热重分析法（TGA）和裂解气相色谱/质谱联用仪（Py-GC/MS）对天然香料琥珀酸单薄荷酯的热失重和热裂解行为及其产物进行了研究。用热重分析法建立了琥珀酸单薄荷酯主反应区热失重过程的动力学模型,并计算出相应的动力学参数。通过Py-GC/MS,分别在300,400,500,600,700,800和900℃下对琥珀酸单薄荷酯进行热裂解,对裂解产物进行了定性和半定量分析。共鉴定出薄荷醇、薄荷烯和琥珀酸等75种裂解产物,并研究了其相对含量随温度升高而变化的规律。结果表明,琥珀酸单薄荷酯在700℃以下裂解出薄荷醇、p-薄荷-3-烯和3-甲基-6-异丙基环己烯等具有致香和清凉作用的物质,而700℃以上没有释放出致香物质。随着裂解温度的升高,裂解产物越来越复杂,有害物质如苯、甲苯、蒽和荧蒽等的含量也逐渐增加。此研究为该化合物在卷烟燃烧过程中的转移行为提供了例证,并为烟草制品加香技术提供了一定的理论依据,有利于琥珀酸单薄荷酯在卷烟产品的应用。     

采用热解技术直接检测纸张中阳离子淀粉含量

介绍了一种能够直接检测并定量分析纸张中阳离子淀粉含量的方法,即热解气相色谱-质谱（Py-GC/MS）法,该方法样品制备过程简单,且可在其他淀粉存在的情况下准确计算纸张中阳离子淀粉含量。实验还研究了该方法的验证特性,如校正标准误差、测定限、线性度和精度等,并将该方法与现有的定量分析方法（SCAN-P 91：09）进行了比较。     

采用热解技术直接检测纸张中的阳离子淀粉含量

<正>热解气相色谱-质谱(Py-GC/MS)法能够直接检测并定量分析纸张中阳离子淀粉含量。与现有的定量分析方法(SCAN-P 91:09)相比,该方法样品制备过程简单、快捷,检测成本较低,在有其他淀粉存在的情况下,也可准确计算出纸张中的阳离子淀粉含量。     

烟叶热裂解产物的分析研究

为研究烟叶热裂解行为对卷烟烟气成分的影响,采用在线热裂解-气相色谱/质谱联用技术(Py-GC/MS)分析烟叶在氦气氛围中不同温度(300℃,600℃和900℃)下的热裂解产物.将热解产物直接引入气相色谱-质谱仪,用质谱法对裂解产物进行了定性分析,并用面积归一法定量分析.结果表明:300℃,600℃和900℃下的热裂解产物中分别鉴定出45种、110种和124种裂解产物;裂解温度对烟叶产生的裂解产物种类和相对含量都有较大影响,裂解出的致香成分包括酮类、醇类、醛类、酯和内酯类、酸类和氮杂环类等,其相对含量在裂解温度为600℃时达到最大.     

枇杷叶浸膏热裂解产物的研究

为了研究枇杷叶浸膏的热裂解产物对卷烟烟气成分的影响,采用在线热裂解-气相色谱/质谱联用技术(Py-GC/MS),研究枇杷叶浸膏在不同温度(300,600和900℃)下的热裂解行为,将热解产物直接引入气相色谱-质谱仪,用质谱法对裂解产物进行定性分析,并用面积归一法半定量分析。结果表明:枇杷叶浸膏裂解产物中主要包括醇类、酯类、酮类和有机酸等化学物质,其中含量较高的物质包括4-戊炔-1-醇,乙二酸和法呢醇等化合物,枇杷叶浸膏热裂解产生较多烟草中主要致香成分,包括β-甜没药烯、二氢猕猴桃内酯、糠醛、苄醇、巨豆三烯酮、2-乙酰基呋喃和棕榈酸等致香物质,这些物质有助于丰富卷烟香气,使烟气柔和。     

基于Py-GC/MS技术的Pd/C催化乙醇木质素热解油特性研究

以毛竹为原料,结合Py-GC/MS热裂解技术,研究不同球磨处理过程中Pd/C催化剂加入对乙醇木质素热裂解油组成的影响作用。实验结果表明:乙醇木质素提取过程加入Pd/C催化剂对木质素得率产生明显影响作用。球磨3d,2%Pd/C催化剂对乙醇木质素的得率提升作用最大,其得率为43.81%。乙醇木质素热裂解产物主要为酚类物质,愈创木酚和苯酚类物质含量较高。球磨处理程度和Pd/C催化剂加入量对单酚产物组成产生影响,其中,Pd/C催化剂用量增加导致2-甲氧基苯酚得率增加。     

气相色谱-串联质谱法（GC/MS/MS）测定酱油中氨基甲酸乙酯的含量

建立了气相色谱-串联质谱法测定酱油中氨基甲酸乙酯的方法,酱油样品在层析柱中用乙醇：二氯甲烷（1：9）洗脱,采用DB-225MS毛细管柱分离样品,GC/MS/MS检测氨基甲酸乙酯的含量,方法线性范围为5-500μg/L,方法检出限和定量限分别为5和10μg/kg,标准加入20-500μg/kg的平均回收率为88.00%-93.58%,本方法具有操作简便、快速、准确等优点,适用于酱油中的氨基甲酸乙酯检测。     

提高硫酸盐桉木浆白度稳定性的新方法

研究比较了采用OZ／EDPo及OZ/EDP的ECF漂序漂白桉木浆和0DHT PoDD及ODHTPoDP常规ECF漂序漂白桉木浆的白度稳定性,探讨了OZ／EDP漂序中03、ClO2和H2O2的用量对纸浆干、湿热返黄值的影响。此外,用Py-GC／MS/MS定了OZ／EDP和ODHTPoDD漂序漂白浆中的芳香化合物成分,并评价了芳香化合物对返黄的影响．同时,提出了桉木浆热返黄的机理。     

1-L-丙氨酸-1-脱氧-D-果糖的热裂解分析

采用热重/差热(TG-DTA)和在线裂解气相色谱/质谱联用(Py-GC/MS)分析技术对1-L-丙氨酸-1-脱氧-D-果糖(Ala-Fru)的热裂解进行了研究.TG-DTA分析结果显示,Ala-Fru的初始裂解温度为147.47℃,600℃时样品质量损失至原重的25%;在350℃,450℃,550℃,650℃,750℃和850℃这6个温度下的Py-GC/MS结果显示,裂解产物的种类和数量随裂解温度的升高而增多,其裂解产物主要为吡嗪类、吡啶类、吡咯类和呋喃类等杂环类化合物以及少量酮类化合物,这些物质是卷烟烟气中重要的香味成分.     

Monitoring Phenolic Composition of Maturing Maize Stover by High Performance Liquid Chromatography and Pyrolysis/Gas Chromatography/Mass Spectrometry*

Maize stovers collected every 14 days over an 84-day growth period were subjected to high-performance liquid chromatography with electrochemical detector (HPLC-ED) and pyrolysis/gas chromatography/mass spectrometry (PY/GC/MS) in order to monitor changes in the phenolic composition. Prior to HPLC-ED analyses, ground samples were sequentially extracted with (i) methanol, (ii) 0·1M sodium hydroxide and (iii) 2M sodium hydroxide in the presence of nitrobenzene to separate, respectively, free phenolic monomers, alkali-labile phenolic monomers and alkali-resistant lignin. In turn, solution (ii) was treated with alkaline nitrobenzene to obtain (iv) alkali-labile lignin. Pyrolysis was carried out on ground native samples by using a platinum heated filament pyrolyser. Increases in the absolute phenolic concentrations in the residues of 0·1M sodium hydroxide extraction and in the ratio of alkali-resistant lignin vs total lignin were observed by HPLC-ED during the first 28–42 days of maturation, reaching a steady level in the remaining maturation period. A linear increase of syringyl units vs guaiacyl units was for found the alkali-resistant lignin fraction over the entire period of maturation. Similar trends were showed by PY/GC/MS with regard to relative lignin content and syringyl/guaiacyl ratio. Both techniques showed their usefulness to gauge changes in the phenolic composition during the lignification process.     

Roasted Chicory Aroma Evaluation by Gas Chromatography/Mass Spectrometry/Olfactometry

Volatiles were isolated from roasted chicory by simultaneous steam distillation-solvent extraction (SDE) and dynamic headspace sampling (DHS). Many volatile components were identified in SDE (92) and DHS (64) extracts. Many pyrazines and N-furfurylpyrroles (N-furfurylpyrrole, N-furfuryl-2-formylpyrrole, and N-furfuryl-2-acetylpyrrole) were identified for the first time in roasted chicory. Aroma extract dilution analysis showed that those extracts from SDE and DHS were similar with respect to predominant aroma-active components. 2-Ethyl-3,5-dimethylpyrazine, 2,3-butanedione, 1-octen-3-one, 3-methylbutanal, and one unknown compound with a chicory- and burnt sugar-like note were the most intense aroma-active components found in roasted chicory.     

Measurement of Amylose/Amylopectin Ratio by High-Performance Liquid Chromatography

Amylose content has been measured by iso-amylase digestion of starch followed by quantitation of the amounts of the higher molecular weight chains (from amylose) and the lower molecular weight chains (from amylopectin). The separatrion and quantitation has been performed by size-exclusion high performance liquid chromatography on hydrophilic columns. Three columns were tested and an Ultrahydrogel 250 was found to provide the optimum separation. Starches of up to 30-35 per cent amylose may be analysed in this way without the need for first removing the lipids. With starch of higher amylose content, precipitation of the amylose in the sample may occur while it is awaiting HPLC analysis. This precipitation can be prevented in starches of up to 40 per cent amylose by the use of dimethyl sulfoxide in the reaction mixture. Samples with amylose content higher than this always show some precipitation and the amylose contents obtained are similar for all starches with amylose in the range from 40 to 80 per cent, measured by iodine determination. The method gives results which are more repeatable than those obtained by spectrophotometric determination of iodine binding, and which appear to be unaffected by the lipid content of the starch.     

油茶皂素大孔树脂纯化工艺优化及LC/TOF-MS分析

以市售低纯度茶皂素粗品为原料,采用AB-8大孔树脂进行纯化,得到最佳纯化工艺为30g/L粗皂素溶液上样,30%乙醇洗脱除去多数色素和部分蛋白等杂质,70%乙醇溶液主要洗脱出茶皂素,油茶皂素的得率为55.5%,纯度提高1.86倍。大孔树脂重复利用8次后,吸附和洗脱效果基本不变,放大试验证明其适合工业化生产。LC/TOF-MS分析表明油茶皂素的分子质量主要集中在1170～1304D之间,并确定了一种油茶皂素的分子式为C58H89O26,同时推测了其结构式。     

烹调油烟冷凝物的紫外吸收光谱和色谱/质谱分析研究

利用紫外法和色质联用法测定了菜油色拉油和猪油经高温(190℃～200℃、230℃～240℃和270℃～280℃)加热产生的油烟冷凝物的成分.油烟冷凝物在260～270nm处有一吸收峰,在相同条件下,菜油色拉油油烟冷凝物的吸光度大于猪油油烟冷凝物的吸光度.结合GC/MS分析结果,认为对紫外吸收有贡献的化合物主要是2,4-庚二烯醛,2,4-葵二烯醛等2,4-二烯和其它其轭化合物.GC/MS结果表明菜油色拉油和猪油加热氧化生成醛类化合物的相对含量随着温度升高而增加,当温度升高至270℃～280℃,总醛峰面积可达30%～50%.菜油色拉油和猪油的油烟冷凝物中都含有大量的己醛和2-庚烯醛.     

烹调油烟冷凝物的紫外吸收光谱和色谱／质谱分析研究注

利用紫外法和色质联用法测定了菜油色拉油和猪油经高温（190℃－200℃、230℃－240℃和270℃－280℃）加热产生的油烟冷凝物的成分。油烟冷凝物在260－270nm处有一吸收峰，在相同条件下，菜油色拉油油烟冷凝物的吸光度大于午猪油油烟冷凝物的吸光度。结合GC／MS分析结果，认为对紫外吸收有贡献的化全物主要是2，4－庚二烯醛，2，4－葵二烯醛等2，4－二烯和其它其轭化合物。GC／MS结果表明菜油色拉油和猪油加热氧化生成醛类化合物的相对含量随着温度升高而增加，当温度升高至270℃－280℃，总醛峰面积可达30％－50％。菜油色拉油和猪油的油烟冷凝物中都含有大量的己醛和2－庚烯醛。     

Determination of Volatile and Semivolatile Contaminants in Meat by Supercritical Fluid Extraction/Gas Chromatography/Mass Spectrometry

Meat products that were exposed to a warehouse fire were collected and examined to identify contaminants present in the samples. An extraction method using supercritical carbon dioxide at 100 atm and 60°C was developed to analyse and characterise volatile and semi-volatile compounds from the samples. The major volatile compounds were lipid oxidation products, such as hexanal and nonanal. Volatiles concentrations from fire-exposed meat products were compared to control samples to determine compositional differences. Aromatic and polycyclic aromatic hydrocarbons were identified, and naphthalene was measured in suspected fire-damaged meat products. Direct supercritical extraction from the meat samples proved to be a rapid and reproducible method to assess contamination in commercial meat products.     

吹扫捕集-气相色谱/质谱联用分析玫瑰花水香气成分

采用吹扫捕集-气相色谱/质谱联用技术首次分析了玫瑰花水的香气组成成分,并对苦水和大马士革两种玫瑰花水香气成分进行比较。结果表明,吹扫捕集最优实验参数为:样品量7.0 mL;吹扫温度40℃;吹扫时间13 min,此时苦水和大马士革玫瑰花水共鉴定出香气成分71种,其中苦水玫瑰花水69种,大马士革玫瑰花水61种;苦水、大马士革共有成分59种,苦水玫瑰花水特有成分10种(相对含量之和为4.15%),大马士革玫瑰花水特有成分2种,相对含量之和为0.54%。吹扫捕集法分析玫瑰花水香气成分操作简单,浓缩富集效率高,重现性好,绿色环保,真实全面地反映了玫瑰花水香气成分的构成,为玫瑰花水香气特征研究提供技术支撑,为其开发利用和产品质量控制提供理论依据。     

Characterisation of Commercial Vodkas by Solid-Phase Microextraction and Gas Chromatography/Mass Spectrometry Analysis

A reliable method for the characterisation of vodkas has been developed by application of solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GCMS). Sixty-four samples of commercial Canadian and American vodkas, and one sample each of Japanese and German vodkas, were investigated in this study. The procedure yielded reproducible chromatographic profiles. The detected components were ethyl esters of C₈ to C₁₈ fatty acids at μg litre⁻¹ levels, various additives and contaminants. Distinctive profiles were observed for various brands. Markers for differentiating between Canadian and American vodkas were identified. The results of this study indicate that vodkas are differentiated by the combined effects of the original raw materials, any added substances, and differences in processing.     

气相色谱-质谱联用法测定烟草及烟草制品中的麦角甾醇

为准确测定烟草及烟草制品中麦角甾醇的含量,建立了以7-去氢胆固醇为内标,将麦角甾醇和7-去氢胆固醇衍生后进行GC/MS同步选择离子检测/全扫描的定量检测方法,并采用该法测定了不同种类烟叶及卷烟中的麦角甾醇含量。结果表明:该方法在2.0～200.0μg/mL之间具有良好的线性关系,R2=0.9995。方法的检出限和检测限分别为0.46和1.53 mg/kg,回收率在85.6%～91.3%之间。该方法适用于烟草及烟草制品中麦角甾醇的定量检测。