顶空固相微萃取-气相色谱-质谱联用分析麦冬中有机挥发物

采用顶空固相微萃取-气相色谱-质谱联用(HS-SPME-GC-MS)分析麦冬中挥发性成分,对萃取温度、时间、脱附时间及样品用量等条件进行了优化,方法所得结果与同时蒸馏萃取-气相色谱-质谱联用(SDE-GC-MS)方法比较,相对含量较高的成分基本一致.固相微萃取方法可应用于麦冬中有机挥发性成分的快速分析.     

水和白酒中异味物质检测的研究进展

综述了水和白酒中异味物质检测的样品前处理方法(包括液液萃取、固相萃取、液相微萃取、固相微萃取、搅拌棒吸附萃取、吹扫捕集、顶空等)和检测方法(包括气相色谱法、气相色谱-质谱法、气相色谱-飞行时间质谱法)的研究进展(引用文献52篇)。     

顶空-固相微萃取-气相色谱-质谱法测定烟气中挥发性和半挥发性成分

提出了顶空-固相微萃取-气相色谱-质谱法测定烟气中挥发性和半挥发性成分。结合信息量最大的原则,确定了固相微萃取时萃取纤维头为碳分子筛/聚二甲基硅烷萃取纤维头,萃取温度为70℃,萃取时间为60min。在气相色谱分离中用Agilent DB-1色谱柱为固定相,在质谱分析中采用全扫描模式。结果表明:共鉴定出107种成分,含量最大的成分是烟碱(18.07%),其次是新植二烯(11.46%),主要的3类挥发性和半挥发性成分依次为苯系物、酮类以及杂环类。     

固相微萃取-气相色谱/质谱法建立烟用香精指纹图谱

采用固相微萃取法(SPME)对6批次的烟用HMT-4香精成分进行提取,GC/MS对其进行分析,建立了该香精的GC/MS指纹图谱的研究方法。通过参兑实验考察了色谱指纹图谱用于香精质量控制的可行性。结果表明:SPME法具有操作简便、快速、节能、萃取效率高等特点,适合于烟用香精成分的提取。6批次的HMT-4香精的指纹图谱稳定性好,相似度高,具有很强的特征性和唯一性。通过参兑实验发现色谱指纹图谱能全面、综合、准确地反映烟用香精的质量情况,可以成为烟用香精质量控制的有效手段。     

可卡因及代谢物的分析检测研究进展

综述了近十年来生物检材中可卡因及其代谢物分析常用的样品前处理技术和检测方法,比较了液-液萃取、固相萃取、固相微萃取等提取方法的可行性和局限性及气相色谱、气相色谱-质谱联用、液相色谱-质谱联用等检测方法的应用进展。     

气相色谱-质谱指纹图谱在鉴别人体气味中的应用

利用顶空固相微萃取-气相色谱/质谱法(SPME-GC/MS)分析了人体腋窝气味。以标准品十七烷进行定位,通过谱图分析和相对保留时间计算,确定了八强峰。根据八强峰和指纹图谱分区相似度对指纹图谱进行分析比较,建立了区别不同个体的新方法。该方法能较全面地反映人体气味的特征峰和整体信息,初步探讨了用仪器鉴别不同个体的可能性。     

固相萃取-气相色谱-质谱法分析电子烟烟液中的香味成分

为了检测电子烟烟液中的香味成分,建立了固相萃取-气相色谱质谱检测方法。利用Li Chrolut EN固相萃取柱富集香味成分,以二氯甲烷为洗脱剂,洗脱液用气相色谱串联质谱分析。方法能有效富集烟液中的香味物质,排除雾化剂(甘油、丙二醇)对香味成分的干扰;重复性较好,大部分化合物峰面积相对标准偏差小于10%。利用该方法分析了4种烟液样品,结果不同口味电子烟所含香味成分差别较大。     

水和食品中有机磷农药残留检测的研究进展

综述了水和食品中有机磷农药残留检测中样品的前处理方法 (包括液液萃取、固相萃取、液相微萃取、固相微萃取、拌棒吸附萃取、磁固相萃取、QuEChERS等)和测定方法(包括气相色谱法、气相色谱-质谱法、液相色谱法、液相色谱-质谱法等)的研究进展(引用文献58篇)。     

食品及食品包装材料中光引发剂分析方法的研究进展

综述了食品及食品包装材料中光引发剂分析方法的研究进展,包括样品的前处理方法(如固相萃取、固相微萃取、基质分散固相萃取、加速溶剂萃取、分散液液微萃取、凝胶渗透色谱)和分析方法(如气相色谱-质谱法、气相色谱-串联质谱法、液相色谱法、液相色谱-串联质谱法、超高效合相色谱法),并对其发展趋势作了展望。     

固相微萃取/气相色谱-质谱法对乌梅浸膏挥发性成分的分析研究

对乌梅浸膏挥发性物质的固相微萃取条件进行了研究。运用正交实验设计,比较了不同萃取头、平衡温度及采样时间对分析结果的影响,通过气相色谱-质谱(GC-MS)的分析监控,结合信息量最大原则,确定了固相微萃取的最佳条件:萃取纤维头为聚二甲基硅氧烷,平衡温度为70℃,采样时间45 min。通过GC-MS进行定性定量分析,共鉴定出38种成分,主要挥发性成分依次为糠醛(24.88%)、2-甲基-3-羟基苯甲醛(13.57%)和5-甲基糠醛(10.16%)。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene

Theoretical and Experimental Chemistry - The effect of the method of modification of catalysts based on zeolite X by cesium and magnesium cations (ion exchange and impregnation) on the selectivity...     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of tetrabenzoporphins of the basis of isoindoline

Chemistry of Heterocyclic Compounds -