顶空固相微萃取-气相色谱-质谱分析发酵香肠挥发性成分

采用固相微萃取-气相色谱-质谱(SPME-GC-MS)联用分析技术对发酵香肠挥发性成分进行了分析。共鉴定了33种化合物。结果表明，发酵香肠的挥发性成分主要为醇类、酮类、酯类、有机酸类、酚类及醛类等。     

A novel triptycene-terminated polymer used as the gas chromatographic stationary phase towards organic acidic/basic analytes and isomers

This work presents a novel strategy for engineering a GC stationary phase with high selectivity, inertness and thermal stability by introducing the 3D π-rich TP moieties to the terminals of a polar chain polymer. Herein, we provide the first example, i.e., a new TP-terminated polycaprolactone polymer (TPP) as the stationary phase for GC analyses. As demonstrated, the TPP column achieved distinctly improved inertness to fatty acids and aldehydes, and dramatically enhanced thermal stability (about 100 °C higher) over the PCL column. Also, the TPP column exhibited high resolving capability towards the positional isomers of phenols, anilines and alkylated/halobenzenes and showed good potential in detecting minor impurities in chemical products. Importantly, the proposed strategy is facile, feasible and generally applicable to analogous polymers.     

酸枣果肉中挥发性化学成分分析

报道了用蒸馏-萃取法提取酸枣果肉中挥发性物质,测得酸枣果肉挥发油的含量为1．80％,用GC／MS法从酸枣果肉挥发油中分离并确定出43种化学成分。用峰面积归一化法通过化学工作站数据处理系统,得出各化学成分在挥发油中的相对百分含量。其中主要成分为酸类化合物占挥发油总量的52．26％,酚类化合物为9．34％,酯类化合物为23．05％,醛类化合物为2．77％,醚类化合物为2．66％,烷烃化合物为1．89％,其它类化合物仅占3．77％。共占酸枣果肉中挥发油总量的95．62％。     

黄柏挥发性化学成分分析

报道了用同时蒸馏－萃取装置（SDE）提取黄柏的挥发性物质,测得黄柏挥发油的含量为0．45％,用GC／MS法从黄柏挥发油中分离并确认出41种化学成分;用峰面积归一化法通过化学工作站数据处理系统得出各化学成分在挥发油中的百分含量,其中主要成分为酮类（16．38％）、醛类（13．94％）、醇类（8．27％）、酚类（50．38％）、酸类（2．18％）、其他类成分仅占3．33％,共占总检出量的97．5％。     

Essential oil composition of Prasium majus from Croatia

The essential oils from the aerial parts of Prasium majus L., collected during two years in Croatia, were analysed by GC and GC/MS. Fifty-two compounds were identified, representing 90.3-91.8% of the total oils. The major constituents in both samples were fatty acids (particularly hexadecanoic acid and (Z)-octadec-9-enoic acid), lower aliphatic alcohols, aldehydes and acids (major ones oct-1-en-3-ol and (E,E)-hepta-2,4-dienal) and phenylpropane derivatives (e.g. eugenol). Beta-Caryophyllene was the most abundant terpene and (E)-beta-ionone was the major norisoprenoid.     

GC Analysis of Organic Acids and Phenols Using On-Line Methylation with Trimethylsulfonium Hydroxide and PTV Solvent Split Large Volume Injection

The combination of on-line methylation using trimethylsulfonium hydroxide with large volume injection of 100 μL was evaluated for the analysis of organic acids and phenols in water. Solvent split injection was applied with complete evaporation of the solvent before analytes were transferred onto the GC column. Despite complete solvent removal, losses were very low compared to conventional splitless injection even for volatile acidic compounds such as propionic acid and phenol. This is explained by intermediate formation of low volatility trimethylsulfonium salts of the analytes which were held in the injector for long evaporation times of up to 10 min, if the evaporation temperature was as low as 10°C. Using a simple liquid/liquid extraction procedure, volatile fatty acids, dicarboxylic acids, benzoic acids and phenols could be detected in 5 mL of water at concentrations of 0.04–0.1 μmol/L with GC/MS in full scan mode. Lactic, pyruvic, and also malonic acids could only be detected at higher levels because of their limited extractability from water as well as their poorer methylation yields. The method provides an easy way to sensitively detect acidic compounds of medium to high volatility in water. It was applied for screening of organic acids and phenols in batch cultures of anaerobic bacteria of which one example is shown.     

吹扫/捕集-热脱附气质联用法对荷叶挥发油成分的对比分析

采用同时蒸馏萃取提取得到荷叶挥发油, 通过吹扫/捕集-热脱附法(P&T-TD)对上述提取物中挥发性成分进行富集, 以气质联用(GC/MS)进行定性检测, 同时与直接进样GC/MS法分析的成分进行比较. 两种方法成功分离分析出有机酸、酯、醛、醇、酚、烷烃、芳香烃、烯烃以及含氮、硫、氧杂原子的化合物等共计84种成分, 其中P&T-TD GC/MS鉴定出63种有机化合物, GC/MS鉴定出41种有机化合物, 有20种成分共同检出. 对比分析表明: P&T-TD GC/MS的吹扫/捕集-热脱附过程能富集各种组分, 相比GC/MS分析, 可以鉴定出微量成分及更多挥发性和半挥发性成分, 在精油等挥发性成分的分析检测中使用优势明显.     

水稻秸秆石油醚和乙醇萃取物的组成分析

用石油醚和乙醇在索式萃取器中对水稻秸秆进行了萃取,萃取物用傅里叶转换红外光谱仪（FTIR）和气相色谱 质谱联用仪（GC/MS）分析。 结果表明,乙醇和石油醚的萃取率分别为8%和6%。 萃取物中共检测到40种物质,主要分为醇酚（APs）、醛、酮、酸、酯、烃（HCs）及含氮化合物（ONs）7种类别。 其中,石油醚萃取物中酯、HCs和APs 3类物质含量较高,总的相对含量为91.7%;乙醇萃取物中HCs、酸、酯及APs含量较高,总的相对含量为83.9%。 该研究在开发稻秆的高附加值利用方面具有重要的基础理论意义。     

Improved method for extraction of aroma compounds in aged brandies and aqueous alcoholic wood extracts using ultrasound

This work presents a rapid method for dichloromethane extraction of aroma compounds from brandies and aqueous-alcoholic wood extracts, in brandy-like ageing conditions, using ultrasound. The dichloromethane extracts were injected in split mode on a gas chromatographic (GC) system, separated on a DB-WAX capillary column and detected by flame ionisation. The method allowed satisfactory quantification of 37 volatile compounds in brandies (alcohols, esters, acids, furanics, aldehydes and phenols) and 16 volatile compounds in aqueous-alcoholic oak extracts. Linear responses were obtained (0.99-1.00). The repeatability and the detection and quantification limits were also evaluated. The analysis of spiked samples showed that matrix effects do not affect the method performance for the majority of the volatile compounds analysed.     

两种树皮热解微晶结构及生物油组分对比

以针叶材杉木树皮和阔叶材桉木树皮为原料,利用X射线衍射 (XRD) 对两种树皮热解前后固体颗粒微晶结构的变化进行了比较,利用气质联用 (GC-MS)、凝胶渗透色谱 (GPC) 等手段对两种树皮生物油组分进行了对比分析。结果表明,两种树皮中的纤维结构及脂肪链结构在热解过程中发生了分解,基本被破坏。杉木树皮和桉木树皮生物油主要组分相似,含有酸类、酮类、酚类、醇类、醛类、糖类、酯类等类物质,但相对含量存在差异;桉木树皮相对杉木树皮热解生成了较多的酸类、酮类物质,而酚类、醇类、糖类物质相对较少。两种树皮生物油中酚类物质占有较大的比例,以苯酚和邻苯二酚为主。两种树皮生物油主要物质分子量集中在300~500 g/mol,但桉木树皮生物油中分子量在300~500 g/mol的相对含量 (48.18%) 相比杉木树皮 (61.14%) 较少。     

气相色谱/质谱法分析孔石莼中的脂肪酸

建立了孔石莼脂肪酸的气相色谱/质谱(GC/MS)测定方法。使用Folch法提取了孔石莼中的总脂,经过2 mol/L HCl-甲醇溶液的甲酯化处理后,采用GC/MS法对其脂肪酸组成进行了分离分析,同时结合有机质谱学规律,分别对饱和脂肪酸甲酯、单不饱和脂肪酸甲酯和多不饱和脂肪酸甲酯的裂解规律和质谱特征进行了分析归纳。通过质谱数据库检索和标准品对照,鉴定出孔石莼中的24种脂肪酸,其中9,12,15-十八碳三烯酸、4,7,10,13-十六碳四烯酸和6,9,2,15-十八碳四烯酸3种主要多不饱和脂肪酸占总脂肪酸含量的45.14%。通过对孔石莼中脂肪酸的分析,表明特征离子在脂肪酸甲酯尤其是多不饱和脂肪酸甲酯的定性方面具有很好的应用价值。     

气相色谱法直接测定工业油酸中脂肪酸

建立了气相色谱直接测定工业油酸中未衍生化的6种常见脂肪酸含量的检测方法。样品用四氢呋喃(THF)溶解,通过氢火焰离子化检测器(FID)对目标化合物进行分析,外标法定量。在优化的气相色谱条件下,6种脂肪酸实现了有效分离,6种脂肪酸在5~5000 mg/L范围内定量曲线的相关系数(R2)均大于0.99991,表明线性关系良好,方法检出限(S/N≥3)为0.36~0.58 mg/L,相对标准偏差为3.4%~8.1%,加标回收率在84.7%~110.2%之间。选取4种工业油酸样品进行分析,实验结果表明,样品未经衍生化处理直接进样,本方法在10 min内能够对6种脂肪酸实现基线分离,为工业油酸的品质鉴定提供了一种快速有效的检测方法。     

Static–dynamic sequential superheated liquid extraction of phenols and fatty acids from alperujo

Superheated liquids of different polarity have been used for sequential extraction of fatty acids and phenols from alperujo. Multivariate methodology has been used to optimise the static–dynamic extraction. Forty-two minutes are required to complete extraction (20 mg/kg of fatty acids and up to 2,200 mg/kg of hydroxytyrosol in the raw material used). The efficacy of the extraction has been demonstrated and compared with that of conventional methods (Folch and stirring-based methods for fatty acids and phenols, respectively), which needed 4.5 and 24 h for the extraction of fatty acids and phenols, respectively. The non-polar and polar extracts were injected into GC–MS and HPLC–MS–MS equipment, respectively, for individual separation–quantification of the target compounds. The simplicity of the experimental setup and the low costs of the raw material make the proposed method advisable when extraction of both fractions is required.     

Contribution to the analysis of the essential oil of Helichrysum italicum (Roth) G. Don. Determination of ester bonded acids and phenols

The essential oil of Helichrysum italicum (Roth) G. Don (everlasting or Immortelle essential oil) was isolated by hydrodistillation and analysed by GC and GCMS. Forty four compounds were identified. The main components were alpha-pinene(12.8%), 2-methyl-cyclohexyl pentanoate (11.1 %), neryl acetate (10.4%), 1,7-di-epi-alpha-cedrene (6.8%) and other compounds. The oil was fractionated and ester-containing fraction was hydrolysed with KOH/H(2)SO(4). The liberated volatiles were analysed by GC and GC-MS: three phenols and twenty seven volatile carboxylic acids were identified[70% low fatty acids (C(2)-C(5)), 15% C(10)-C(12) acids and 15% other acids]. The main acids were acetic acid (24.3%) propanoic acid (17.2%), 2-methylpropanoic acid (11.4%),dodecanoic acid (8.7%), 2-methylbutanoic acid (8.3%), (Z)-2-methylbutenoic acid(5.1%) and decanoic acid (4.6%). With respect to the identified bonded carboxylic acids,the minimal number of esters in the oil was twenty seven, but their overall quantity was probably larger due to different possible combinations of alcohols with acids to form esters. On the other hand, only six main esters were identified in the oil before fractionation and hydrolysis.     

Isolation and identification of flower oil components from four <Emphasis Type="Italic">Staphylea</Emphasis> L. species

Chemical composition of the hydrodistilled volatile fraction from flowers of four Staphylea L. species (Staphylea colchica Stev., Staphylea elegans Zab., Staphylea holocarpa Hemsl., Staphylea pinnata L.) was determined by the GC/MS method. Compounds in fresh and dried flowers (stored for 1 year) were determined. Mostly, structures of different oxygenated aliphatic hydrocarbons in all four species were found. Different aldehydes, ketones, esters of higher fatty acids, and hexadecanoic acid were identified, with dominating content of tricosane, hexadecanoic acid and also of heneicosane, pentacosane, heptacosane, and nonacosane. In S. pinnata L. (fresh flowers) some nonaliphatic hydrocarbons, and in S. holocarpa Hemsl. (fresh flowers) esters of higher fatty acids were found.     

Microwave-assisted phase-transfer catalysis for the rapid one-pot methylation and gas chromatographic determination of phenolics

Microwave-assisted phase-transfer catalysis (PTC) is reported for the first time, for the one-step extraction–derivatization–preconcentration and gas chromatographic determination of twenty phenols and ten phenolic acids. The well established phase-transfer catalytic methylation is largely accelerated when heating is replaced with the “greener” microwave irradiation. The overall procedure was thoroughly optimized and the analytes were determined by GC/MS. The method presented adequate analytical characteristics being more sensitive in analyzing phenols than phenolic acids. The limits of detection without any additional preconcentration steps (e.g. solvent evaporation) were adequate and ranged from 0.4 to 15.8 ng/mL while limits of quantitation were between 1.2 and 33.3 ng/mL. The method was applied to the determination of phenols, in spiked environmental samples and phenolic acids in aqueous infusions of commercially available pharmaceutical dry plants. The recoveries of fortified composite lake water samples and Mentha spicata aqueous infusions ranged from 89.3% to 117.3% for phenols and 93.3% to 115.2% for phenolic acids.     

Simultaneous Analysis of Lipid-Soluble Constituents of Erxian Decoction by GC–MS

Erxian Decoction (EXD), a traditional Chinese medicine formula mainly composed of six Chinese herbs, was originally developed for menopausal syndromes and had been practiced since the 1950s in China. Previous studies only focused on the water-soluble compounds involved in EXD by LC or TLC. This study analyzed the whole profile of the volatile constituents contained in EXD to supplement its quality evaluation method. Several EXD samples were extracted with chloroform and ethyl acetate, respectively, to get the lipid-soluble chloroform and ethyl acetate fractions and compared their gas chromatographic profiles by GC–MS. The EXD samples were hydrolyzed with hydrochloric acid in a water-bath at 100 °C, neutralized with 40% NaOH, and finally extracted with ethyl acetate and chloroform for the quantification of the total sarsasapogenins contained in EXD. A total of 56 compounds belonging to a variety of natural product categories such as aromatic phenols, terpenes, fatty acids, ketones, esters, and aldehydes, etc. were identified from the chloroform and ethyl acetate extracts by using the online EI–MS characterization. The GC–MS method showed a linear response for sarsasapogenin quantification with r = 0.994. The intra-day and inter-day variations of precision and accuracy of the assay were less than 5%. This developed GC–MS method could thus be successfully applied for the identification of lipid-soluble constituents derived from EXD, and also for the accurate quantification of the total sarsasapogenins contained in the acid hydrolyzed EXD samples.     

毛细管气相色谱和气相色谱/质谱法分析五灵脂挥发性成分

利用同时蒸馏萃取法（SDE）提取五灵中的挥发性组分。SE－54柱和PEG－20M柱上用气相色谱－质谱法分别检出122个和96个峰。其中有51种峰质谱检索结果相同,它们占总峰面积的56.3％。进一步用程序升温保留指数确认了其中33种化合物,占总峰面积的35.7%。含量较高的组分有：十二酸（7.00%),α－雪松醇（4.41％）,四甲基吡嗪（4.10%）,寸上酸（3.37％）,1－（3－甲苯基）乙酮（2.53%),苯甲醛（2.42％）,2－甲氧基苯酚（2.11%)。从化合物的种类来看,主要为醇类（10种）,酮类（8种）,醛类（8种）,醛类（6种）、烯类（5种）、酸类（4种）,酚类（4种）。     

Exploring the fatty acids of vernix caseosa in form of their methyl esters by off-line coupling of non-aqueous reversed phase high performance liquid chromatography and gas chromatography coupled to mass spectrometry

Vernix caseosa is a greasy biofilm formed on the skin of the human fetus in the last period of pregnancy. This matrix is known to contain a range of uncommon branched chain fatty acids. In this study, we studied the fatty acid composition of vernix caseosa by non-aqueous reversed phase high performance liquid chromatography (RP-HPLC) fractionation followed by gas chromatography-electron ionization mass spectrometry (GC/EI-MS) of the fractions. For this purpose the fatty acids from vernix caseosa were converted into the corresponding methyl esters. These were fractionated by non-aqueous RP-HPLC using three serially connected C(18)-columns and pure methanol as the eluent. Aliquots of the HPLC fractions were directly analyzed by GC/EI-MS in the selected ion monitoring mode. Data analysis and visualization were performed by the creation of a two dimensional (2D) contour plot, in which GC retention times were plotted against the HPLC fractions. Inspection of the plot resulted in the detection of 133 different fatty acids but only 16 of them contributed more than 1% to the total fatty acids detected. Identification was based on HPLC and GC retention data, GC/MS-SIM and full scan data, as well as plotting the logarithmic retention times against the longest straight carbon chain. In selected cases, aliquots of the HPLC fractions were hydrogenated or studied by means of the picolinyl esters. Using these techniques, the number of double bonds could be unequivocally assigned to all fatty acids. Moreover, the number of methyl branches, and in many cases the positions of methyl branches could be determined. The enantioselective analysis of chiral anteiso-fatty acids resulted in the dominance of the S-enantiomers. However, high proportions of R-a13:0, R-a15:0, and R-a17:1 were also detected while a17:0 was virtually S-enantiopure.     

Preparation and characteristics of high pH-resistant sol-gel alumina-based hybrid organic-inorganic coating for solid-phase microextraction of polar compounds

A novel alumina-based hybrid organic-inorganic sol-gel coating was first developed for solid-phase microextraction (SPME) from a highly reactive alkoxide precursor, aluminum sec-butoxide, and a sol-gel-active organic polymer hydroxyl-terminated polydimethylsiloxane (OH-TSO). The underlying mechanism was discussed and confirmed by IR spectra. The porous surface structure of the sol-gel coating was revealed by scanning electron microscopy. A detailed investigation was conducted to evaluate the remarked performance of the newly developed sol-gel alumina-OH-TSO hybrid materials. In stark contrast to the sol-gel silica-based coating, the alumina-based coating demonstrated excellent pH stability. In addition, good thermal resistance and coating preparation reproducibility are also its outstanding performance. As compared to silica-based hybrids material, the ligand exchange ability of alumina makes it structurally superior extraction sorbents for polar compounds, such as fatty acids, phenols, alcohols, aldehydes and amines. Practical applicability of the prepared alumina-OH-TSO fiber was demonstrated through the analysis of volatile alcohols and fatty acids in beer. The recoveries obtained ranged from 85.7 to 104% and the relative standard deviation values for all analytes were below 9%.