SDE/SPME-GC-MS分析苦荞的挥发性香气成分

为了分析不同方法萃取苦荞样品中挥发性物质的差异,采用同时蒸馏萃取法（SDE）和固相微萃取法（SPME）提取苦荞样品中的挥发性成分,用气相色谱-质谱联用（GC-MS）技术定性鉴定,并用总离子流色谱峰的峰面积进行归一化定量分析。同时蒸馏萃取-气谱-质谱法（SDE-GC-MS）分析出23种挥发性成分,固相微萃取-气相色谱-质谱法（SPME-GC-MS）分析出35种挥发性成分,2种方法均提取出酯类、烃类、酮类、醛类和醇类,其中酯类和醛类的含量较多,说明酯类和醛类对苦荞的风味贡献较大。同时蒸馏萃取法适合对高沸点、低挥发性物质进行分离,固相微萃取法具有快速简便、不使用溶剂和样品检测非破坏性等优点,适合易挥发性化合物的检测。将两种提取方法相结合对苦荞挥发性物质提取能得到比较全面的结果。     

SPME-GC/MS法分析开阳富硒茶香气成分

采用顶空固相微萃取技术(HS-SPME)提取贵州开阳富硒茶中挥发性香气成分,并结合气相色谱-质谱联用法(GC-MS)进行分析,研究固相微萃取头的种类、温度、吸附和解吸附时间等条件对香气物质的影响。研究结果表明:采用DVB/CAR/PDMS复合型固相微萃取头,于80℃下顶空萃取1 h吸附效果最佳;所吸附挥发性香气物质经GC-MS分析,共鉴定出种香气成分57种,其中醇类14种(相对含量29.62%),醛类9种(相对含量22.53%),烷烃14种(相对含量11.07%),酮类9种(相对含量4.92%),酯类和烯烃含量较低。     

小米不同热处理对小米醋挥发性成分的影响

为研究小米不同热处理对小米醋挥发性成分的影响，采用电子鼻结合气相色谱-质谱法对小米醋挥发性成分进行分析。电子鼻对整体挥发性成分区分效果明显，以传感器W1W和W5S为主要区分指标。通过优化顶空固相微萃取条件，确定羧基/聚二甲基硅氧烷CAR/PDMS(85μm)萃取头、样品量8 mL、萃取温度60℃、萃取时间35 min条件下小米醋挥发性成分萃取效果最佳。采用气相色谱-质谱法分析小米醋挥发性成分，发现普通小米醋酚类物质含量较高，炒制小米醋醛类物质含量较高，膨化小米醋酯类和醇类物质含量明显提高。酯类、醛类和醇类是小米醋的重要香气物质。小米不同热处理对小米醋挥发性成分有积极作用，可为小米醋挥发性成分的研究提供理论依据和技术参考。     

玫瑰花挥发性化学成分的分析研究

利用固相微萃取-气相色谱-质谱联用技术研究北京种植玫瑰鲜花挥发性成分及其相对含量。结果表明:使用聚二甲基硅氧烷-二乙烯基苯纤维萃取头在25℃下萃取30 min,能有效地吸附玫瑰花中的挥发性成分,分析其主要挥发性成分为香茅醇(40.38%)、香叶醇(13.49%)、苯乙醇(12.29%)、月桂烯(7.12%)和α-蒎烯(5.65%)等醇类、醚类、酯类以及各种烷烃类化合物,醇类和酯类化合物是主要香气成分。采用水蒸汽蒸馏法和超临界CO2萃取法分别提取玫瑰鲜花精油,经气相色谱质谱法鉴定挥发性化学成分。比较分析3种方法的测定结果,发现提取方法影响精油的品质,水蒸气法提取的精油香气成分更接近玫瑰花自然状态下的"香气"状况。     

食用油挥发性物质固相微萃取GC-MS分析

以食用油为材料,采用固相微萃取、气相色谱-质谱联用仪和50/30 um DVB/CAR/PDMS纤维头测定其中的挥发性物质。结果表明:从被鉴定的7种食用油中确定293种挥发性物质,包括醛类、醇类、酯类、烷类、酮类、腈类等物质。其中,醛、醇、酯类挥发性物质种类较多,醛类49种,醇类29种,酯类29种。醛类物质的百分含量最大,为30%。被鉴定的各食用油香味组成成分类似,其中醛类化合物在各种食用油中均大量存在。     

顶空固相微萃取结合GC-MS分析花椒油香气成分

采用顶空固相微萃取结合气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)联用方法对市售花椒油挥发性香气成分进行初步分析。结果表明:采用50/30μm DVB/CAR/PDMS萃取头,在磁力搅拌条件下,萃取温度为50℃、萃取时间为40 min时花椒油中的挥发性风味物质能最大程度地挥发、吸附。在花椒油中共鉴定出47种挥发性香气成分,主要为醇类9种(18.94%)、烯烃类19种(50.85%)、酯类5种(21.35%)、酮类6种(5.09%)、醛类8种(3.42%)。花椒油中香气成分主要是以醇类、醛类和酯类物质为主,桧烯(13.05%)、(E)-β-罗勒烯(14.65%)、桉油精(12.16%)、乙酸芳樟酯(17.65%)是其主要的挥发性化合物。     

陈酿时间对黄酒中挥发性风味物质和氨基酸含量的影响研究

该研究考察了6种不同陈酿年份绍兴黄酒中挥发性风味物质和氨基酸的变化。通过固相微萃取-气相色谱-质谱联用（SPME-GC-MS）法对不同储存年份黄酒中挥发性风味物质进行分析,并通过全自动氨基酸分析仪检测了6种不同陈酿年份黄酒样品中的游离氨基酸。结果表明,黄酒中共鉴定出28种主要挥发性风味成分,分别为酯类13种、醇类4种、醛类5种、酮类2种、其他类4种;随着陈酿年份的增加,酒体愈加香气浓郁,酒味醇厚;醇类物质随着年份的增加而逐渐减少,酯类化合物随着年份的增加而增加。共检测出16种游离氨基酸,其氨基酸总含量为2.80～3.98 g/L,其中包括7种必需氨基酸以及9种非必需氨基酸,且必需氨基酸含量占氨基酸总含量的35%左右。通过实验发现,3～12年陈酿的黄酒中,随着陈酿年份的增长,酯类物质含量增加,游离氨基酸含量整体呈现上升趋势,而陈酿12年后,游离氨基酸含量急速下降。     

不同成熟度乍娜葡萄挥发性香气成分分析

采用固相微萃取法,分别使用50/30μmCAR/DVB/PDMS和100μmPDMS萃取头萃取了乍娜葡萄的香气成分。通过比较萃取物质的种类和含量,选定50/30μmCAR/DVB/PDMS为最佳萃取头,并利用该萃取头结合气相色谱质谱联用(GC-MS)技术测定了3种不同成熟度乍娜葡萄的挥发性香气成分。结果表明:乍娜葡萄的香气成分主要由酯类、醇类、醛类和酸类组成,其中含量较高有乙酸乙酯、1-己醇、(E)-2-己烯-1-醇、(E)-2-己烯醛等。随着成熟度的增加,香气成分的总量增加,其中酯类、醛类和酸类总量和相对含量均下降,醇类含量升高。     

山乌桕蜂蜜醋香味成分的GC-MS分析

采用固相微萃取法提取山乌桕蜂蜜醋中的香气成分,并用气相色谱-质谱法对其成分进行了分析,共分离鉴定出50种化合物,包括酸类、酯类、醇类、醛类、酮类、酚类、烃类以及少量其它化合物.采用峰面积归一法对所测的山乌桕蜂蜜醋香气成分进行定量分析发现,鉴定的50种化合物量占总挥发性成分的98.93%,其中酸类占27.4%、酯类占30.38%、醇类占18.79%、醛类占15.22%、酮类占3.09%、酚类占2.51%及烃类占1.07%.这些物质相互作用构成了山乌桕蜂蜜醋独特的香味.     

兼香型白酒贮存期挥发性成分变化规律

对不同贮存期兼香型白酒的挥发性成分和三维荧光光谱进行测定。利用固相微萃取对挥发性成分进行提取、气相色谱-质谱法定性、内标法定量,对5 个不同贮存期酒样挥发性成分的变化进行研究。结果表明,不同贮存期酒样中的酸类物质相对含量呈上升趋势,醇类物质相对含量略有增加,酯类物质部分上升部分呈下降趋势。利用三维荧光光谱对不同贮存期酒样进行了测定,初步探讨了三维荧光在兼香型白酒酒龄方面的应用。     

气相色谱-质谱法中4种不同捕集方式对茶叶香气成分测定的影响

采用固相微萃取(solid phase microextraction,SPME)、吹扫捕集-热脱附(purge & trap-thermal desorption,P&T-TD)、搅拌磁子吸附(stir bar sorptive extraction,SBSE)、动态顶空吸附(head space sorptive extraction,HSSE-1、HSSE-2和HSSE-3)4种捕集方式联用气相色谱-质谱仪对杭州龙井茶、黄山毛峰茶、山东崂山茶和福建乌龙茶进行分析,研究茶的挥发性香气组分。结果显示：茶的香气主要由烯类、醛类、醇类、酮类、酯类、酸类、芳香族化合物、含氮化合物、杂环化合物、含硫化合物、酚类化合物组成;4类茶均含有大量的烯类、醛类、醇类和酮类化合物,其中福建乌龙茶含量最高;杭州龙井茶、黄山毛峰茶和山东崂山茶属绿茶类,酯类、杂环类、芳香族类以及酚类化合物含量相对较高;通过HSSE-1、HSSE-2对茶叶香气成分进行对比,冲泡前后组分种类和含量略有不同。组分之间的差异使茶形成不同产地不同种类的茶叶的特有风味。     

Determination of flavour compounds in beer using stir‐bar sorptive extraction and solid‐phase microextraction

The analysis of volatile compounds in beer is important for quality control in the brewing industry. In this study, stir‐bar sorptive extraction (SBSE) and solid‐phase microextraction (SPME), two solvent‐less enrichment techniques, were applied in combination with gas chromatography flame ionization detection (GC/FID) for the determination of four flavour compounds (isoamyl acetate, ethyl hexanoate, benzaldehyde, myrcene) in beer. Limits of detection, linearity and repeatability of both methods were determined using standard ethanol solutions, while accuracy was determined by conducting recovery tests on commercial beer samples. Both methods were characterized by high linearity (r > 0.996) and repeatability (RSD = 1.76–10.66%). When both methods were compared, higher recoveries were obtained by SBSE, with limits of detection 1.8–2.8 times lower compared with SPME. In the analysis of commercial beer samples using both methods, SBSE analysis resulted in higher recoveries, therefore demonstrating promise for the analysis of beer volatiles. Copyright © 2015 The Institute of Brewing & Distilling     

Determination of Some Beer Flavours by Stir Bar Sorptive Extraction and Solvent Back Extraction

This work presents the development of a simple, rapid and low cost method for the determination of some beer flavours as esters such as isoamyl acetate, ethyl caproate, ethyl caprylate, phenyl acetate, ethyl caprate, phenylethyl acetate, ethyl laurate, ethyl myristate and ethyl palmitate using stir bar sorptive extraction (SBSE). The combination of this extraction technique with solvent back extraction and subsequent gas chromatographic analysis with flame ionisation detection was used for the determination of these compounds. The effects of different mixtures of organic solvents and the influence of sampling time and time of solvent back extraction were studied. An optimum procedure for the SBSE method was developed. The method had high repeatability (RSD 2.1–7.3%), good linearity (the correlation coefficients were higher than 0.9995 for quadratic fit over the concentration range from 0.015 to 30 mg/L) and acceptable recoveries (78–107%) and precision (RSD > 7.3%).     

Determination of Selected Beer Flavours: Comparison of a Stir Bar Sorptive Extraction and a Steam Distillation Procedure

The aim of this work was focused on the comparison of two sample preparation procedures — a stir bar sorptive extraction (SBSE) followed by solvent back extraction and a well‐established distillation method followed by liquid/liquid extraction — for the simultaneous determination of some beer esters (isoamyl acetate, ethyl caproate, ethyl caprylate, ethyl caprate, phenyl‐ethyl acetate, ethyl laurate, ethyl myristate, ethyl palmitate) and free fatty acids (caproic, caprylic, pelargonic, capric). Subsequent gas chromatographic analyses with flame ionization detection were used for the determination of these compounds. Both procedures were characterized by good linearity (correlation coefficients were higher than 0.9987). The relative standard deviations were found to be 2.1–7.3% for SBSE and 10–14% for the distillation technique with recovery 81–107% and 70–89%, respectively. Results obtained by these two procedures were in good correlation.     

顶空固相微萃取法(SPME)在红葡萄酒香气成分测定中的应用研究

利用固相微萃取和气质固相微萃取联用技术对赤霞珠干红葡萄酒中的香气成分进行分析,研究了萃取时间、萃取温度、加电解质的量等对红葡萄酒中香气物质萃取的影响,优化了提取条件,建立了快速测定葡萄酒中香气物质的方法。质谱图中共分离出70个峰,利用计算机检索,结合已有的报道鉴定出65种香气物质,根据面积归一法测其相对含量,共占其色谱流出组分总量的98.46%。     

Graphene oxide-coated stir bar sorptive extraction of trace aflatoxins from soy milk followed by high performance liquid chromatography-laser-induced fluorescence detection

Mycotoxins are potential food pollutants produced by fungi. Among them, aflatoxins (AFs) are the most toxic. Therefore, AFs were selected as models, and a sensitive, simple and green graphene oxide (GO)-based stir bar sorptive extraction (SBSE) method was developed for extraction and determination of AFs with high performance liquid chromatography-laser-induced fluorescence detector (HPLC-LIF). This method improved the sensitivity of AFs detection and solved the deposition difficulty of the direct use of GO as adsorbent. Several parameters including a spiked amount of NaCl, stirring rate, extraction time and desorption time were investigated. Under optimal conditions, the quantitative method had low limits of detection of 2.4–8.0 pg/mL, which were better than some reported AFs analytical methods. The developed method has been applied to soy milk samples with good recoveries ranging from 80.5 to 102.3%. The prepared GO-based SBSE can be used as a sensitive screening technique for detecting AFs in soy milk.     

Determination of synthetic phenolic antioxidants in soft drinks by stir-bar sorptive extraction coupled to gas chromatography-mass spectrometry

The synthetic phenolic antioxidants butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ) were pre-concentrated by stir-bar sorptive extraction and thermally desorbed (SBSE-TD) before analysis by GC-MS. Several parameters affecting the derivatisation step and both SBSE extraction and thermal desorption were carefully optimised. When the analyses of BHA and TBHQ in their acetylated, silylated and underivatised forms were compared, the best results were obtained when the in-situ derivatisation procedure with acetic anhydride was employed. Quantification was carried out using carvacrol as the internal standard, providing quantification limits of between 0.11 and 0.15 ng ml^?1, depending on the compound. Recovery assays for samples spiked at two concentration levels, 1 and 5 ng ml^?1, provided recoveries in the 81–117% range. The proposed method was applied in the analysis canned soft drinks and the analytes were found in five of the 10 samples analysed.     

固相微萃取-气相色谱-质谱法测定食品塑料包装袋中6 种酞酸酯类化合物

建立固相微萃取-气相色谱-质谱同时测定食品塑料包装袋中6 种酞酸酯类化合物的分析方法,并对固相微萃取方式、萃取溶剂、萃取头涂层、萃取温度等参数进行优化。采用85 μm PA固相微萃取纤维头、正己烷为萃取溶剂,90 ℃平衡5 min后萃取吸附30 min,在250 ℃进样口解吸5 min后供气相色谱-质谱分析。结果表明：该方法的线性范围为0.25～50 mg/L,方法检出限为0.049～0.920 mg/L,回收率为82.2%～109.0%,相对标准偏差（n=6）为4.0%～12.0%,该方法能很好地富集基体中的目标化合物,满足食品塑料包装袋中多种酞酸酯类化合物的分析要求。     

Quantification of Volatile Compounds in Chinese Ciders by Stir Bar Sorptive Extraction (SBSE) and Gas Chromatography‐Mass Spectrometry (GC‐MS)

A new method for the quantification of volatile compounds in ciders was developed using stir bar sorptive extraction (SBSE) followed by gas chromatography (GC)‐mass spectrometry (MS). The optimized conditions consisted of 10 mL cider sample with NaCl addition to a final concentration of 30% (w/v) extracted by SBSE at 55°C during 60 min, stirring at 1100 rpm. Under the conditions described above, the method linearity was satisfactory, with correlation coefficients (R²) higher than 0.99 in all cases. The detection limits of this method ranged from 0.01 to 6.37 μg/L, and quantification limits ranged from 0.03 to 21.25 μg/L. The recoveries of analyzed compounds varied between 70.92 and 111.38%. The relative standard deviations (RSD) were all below 10%. A total of 54 volatile compounds in six samples from Chinese cider were quantified, mainly esters, alcohols, terpenoids, aromatics, and acids.     

Mechanisms of Extraction of Aroma Compounds from Foods,Using Adsorbents. Effect of Various Parameters

Due to their high adsorbing capacity, different solids (carbonaceous adsorbents, zeolites, and polymers) are used to extract and concentrate aroma compounds from foods. Adsorption mechanisms are described in two phases, a kinetic stage that involves the diffusion of the analytes within the adsorbent pores and a thermodynamic stage that can be described by adsorption isotherms. These two phases determine the extraction time and the capacity of the adsorbent for a given aroma compound. Several applications involving adsorbents or sorbents have been developed, including purge and trap, solid-phase microextraction (SPME), and stir bar sorptive extractions (SBSE), headspace sorptive extraction (HSSE), which now are widely used for aroma extractions. Different extraction modes (in the headspace or by immersion in the sample) can be used to recover aroma compounds in foods. The same adsorption mechanisms take place in both cases. Various parameters affecting the extraction kinetics and the capacity of the adsorbent have to be optimized when developing an extraction method. They can be divided into three groups: physicochemical characteristics of the adsorbent, including its porosity and hydrophobia; physicochemical characteristics of the aroma compounds (among them, two parameters play an important role, the sample/adsorbent partition coefficient, which determines the affinity for the adsorbent and the volumetric mass, which influences the diffusion in the adsorbent pores); and the extrinsic parameters that depend on the sampling conditions such as pH, temperature, gas or solvent flows, time, and composition of the sample. Several models used to determine the diffusivity and partition coefficient of aroma between the food sample and the adsorbents have been developed. They are useful to understand the behavior of aroma compounds in regards to various adsorbents and in selecting the adsorbent material with the greatest affinity for the target aroma compounds. Quantitative studies based on adsorbent extraction of volatiles have been carried out. Nevertheless, competition between analytes and the saturation of these materials are limiting parameters. Thus, new strategies (SBSE, HSSE) are being developed to avoid these limiting aspects of adsorbents in order to use them in a quantitative way.