顶空固相微萃取-气质联用分析小麦储藏过程中挥发性成分变化

采用顶空固相微萃取(HS-SPME)和气相色谱-质谱联用(GC-MS)对不同储藏时间弱(强)筋小麦中的挥发性物质进行提取、鉴定与分析.选用复合萃取纤维二乙烯基苯-炭烯-聚二甲硅氧烷共聚物(DVB/CAR/PDMS)50 μm涂层,对萃取温度、时间、样品用量和解析时间进行优化.结果表明: HS-SPME测定挥发性物质的最佳前处理条件样品量20 g, 萃取温度75 ℃, 萃取时间60 min, 260 ℃条件下解析5 min;经鉴定分析小麦挥发性成分主要有烃类、醛类,其次为醇类、酮类;挥发性成分总含量在储藏6个月内均呈现先降后增的趋势.弱筋小麦的烃类挥发物相对量随储藏时间延长而快速增加,醛类相对含量先降后升,而酮类和醇类相对含量则逐渐下降;强筋小麦中除烃类相对含量呈先下降而后快速增加外,其余各类挥发物含量均与弱筋小麦呈现相同的规律.储藏6个月后,变化较明显的挥发性物质有己醇、己醛、2,6,10-三甲基-十二烷、十五烷和二十烷.     

顶空固相微萃取-气质联用技术分析5种荷花的挥发性成分

采用顶空固相微萃取-气相色谱质谱联用(HS-SPME-GC-MS)技术分析测定了5个品种荷花中的挥发性成分.考察了不同萃取头和萃取温度对荷花挥发性成分萃取的影响,选用65μm PDMS/DVB SPME萃取头和25℃室温萃取荷花中的挥发性成分得到较好的萃取效果.应用峰面积归一化法测定各挥发性成分的相对含量,5个品种共鉴...     

顶空固相微萃取气质联用分析伊犁翠雀花中挥发性成分

采用顶空固相微萃取气质联用(HS-SPME-GC-MS)法对伊犁翠雀花挥发性成分进行提取并鉴定,以色谱峰面积归一化法计算各成分的相对百分含量。结果表明,伊犁翠雀花中鉴定的挥发性成分为38个,其主要成分为(E)-2-庚烯醛(7.76%)、苯甲醛(7.62%)、正辛醇(7.16%)、3,5-辛二烯-2-酮(6.12%)、已醛(3.53%)、1,4-二甲氧基苯(3.27%)、壬醛(3.12%)、反-β-金合欢烯(2.92%)等,伊犁翠雀花的主要挥发性成分为醛类、芳香族、酮类、醇和萜类化合物。     

顶空固相微萃取-气相色谱-质谱联用分析纺织品中挥发性有机物

建立了顶空固相微萃取（HSSPME）-气相色谱（GC）-质谱（MS）联用测定纺织品中甲苯、4-乙烯基环己烯、苯乙烯、萘和1-苯基环己烯5种挥发性有机物（VOCs）的分析方法。选择聚二甲基硅氧烷（PDMS）作为萃取涂层,优化了SPME的萃取条件,包括平衡时间、萃取时间、萃取温度、顶空体积、离子强度、搅拌速度、解吸温度和时间以及GC—MS仪器条件。对于甲苯、4-乙烯基环己烯、苯乙烯、萘和1-苯基环己烯方法线性范围分别为0．087～870、3．32～3320、2．28～2280、0．015～150和0．050～50．0ng／g;检出限分别为0．005、0．042、0．670、0．008和0．011ng／g。实际样品加标回收率在80．1％～122％之间,RSD在0．8％～8．6％之间。方法符合纺织品中痕量VOCs的快速分析要求。     

固相微萃取―气相色谱―质谱联用方法分析人参中的挥发性物质

采用固相微萃取―气相色谱―质谱联用(SPME-GC-MS)的方法测定了人参中的挥发性物质,并对萃取头类型、萃取温度、萃取时间进行了优化。结果表明,当采用100μm聚二甲基硅氧烷(PDMS)的萃取头(非极性),80℃萃取30 min时,萃取效果最好。结果显示,人参中主要的挥发性物质为γ-榄香烯和β-古芸烯等。     

香味文具挥发性成分的分析

介绍适用于香味文具的挥发性成分分析的各种技术,包括样品的前处理以及分离和检测的方法。其中顶空固相微萃取-气相色谱-质谱联用法样品前处理简单,无需溶剂提取,色谱柱损害小,对于分析挥发性成分含量较低的香料样品效果很好。     

顶空固相微萃取-气质联用法检测尿液中的曲马多

建立尿液中曲马多的顶空固相微萃取气相色谱质谱联用(HS-SPME-GC/MS)分析方法。利用响应面法对顶空固相微萃取的条件进行优化,在优化的条件下,采用SKF为内标,在选择离子模式下,选取m/z 58(曲马多)和m/z 86(SKF)为定量离子,利用GC/MS对尿液中的曲马多进行定量分析。工作曲线线性范围超过0.05~1.0μg/mL(r2=0.9962)。检测限为0.011μg/mL(S/N=3),定量限为0.038μg/mL(S/N=10),用0.1μg/mL和0.75μg/mL曲马多标准液计算回收率分别在100.20%~109.65%和98.43%~103.82%之间,RSD为5.32%和9.13%(n=5)。建立的方法适用于尿液中曲马多。     

固相微萃取气质联用分析茉莉花的香气成分

利用顶空固相微萃取技术,采用气质联用仪分析茉莉花的香气成分,在弱极性和极性毛细管色谱柱条件下,分别用PDMS、PDMS/DVB、PA三种萃取头富集香气,分离出100多种香气成分,鉴定出含量大于0.1%的55种组分,占香气成分的97%,三种萃取头所得主成分完全一致,均为芳樟醇、乙酸苄酯、反式-金合欢烯、顺式-苯甲酸-3-己烯酯和吲哚。     

顶空固相微萃取-气相色谱-质谱法测定茶叶中香叶醇

建立了一种应用顶空固相微萃取(HS-SPME)气相色谱质谱(GC-MS)联用分析测定茶叶中香叶醇(Geraniol)的方法。通过考察萃取头型号、茶水比、萃取温度、萃取时间、解吸附温度和解吸附时间等影响因素,确定最佳HS-SPME条件为:DVB/CAR/PDMS型号萃取头、茶水比1:6、萃取温度60℃、萃取时间60 min;气相色谱最佳解吸附条件为:进样口温度240℃、解吸附时间3 min。在优化条件下茶叶样品中的香叶醇得到较好的提取,GC-MS检测线性范围为0.08~16.50μg/g,检出限(S/N≥3)为9.42×10-3μg/g,空白基质加标回收率为89.8%~105.9%。在对24种茶样进行检测后,香叶醇含量范围为0.13~11.85μg/g,相对标准偏差为1.8%~9.7%。方法能满足茶叶样品中香叶醇分析测定的需要。     

蛇油的挥发性成分分析和脱腥

采用水蒸汽蒸馏、黏土吸附、乙醇-乙酸乙酯共沸的方法除去蛇油的腥味,运用顶空固相微萃取(SPME)-气相色谱(GC)-质谱(MS)联用技术分析脱腥前后蛇油中挥发性成分的变化,并运用GC-MS联用技术分析脱腥后的蛇油中的脂肪酸.结果表明水蒸汽蒸馏是效果最佳的脱腥方法,它可使蛇油挥发性成分的量降至脱腥前的38%,使腥味的主要成分减少60%～100%,同时较大程度地保留了多不饱和脂肪酸.     

顶空气相色谱-质谱联用结合同位素峰形校正检索技术鉴别芝麻油风味成分

采用顶空气相色谱-质谱联用(GC-MS)仪结合同位素峰形校正检索技术鉴别了市售芝麻油风味成分中的71种化合物,占总检出化合物的90.2%。检出化合物可分为吡嗪、吡咯、吡啶、噻唑、噻吩、吲哚、唑、呋喃、醛类和酚类等,其中醛、酚、吡嗪和呋喃类化合物的含量较高,分别占风味成分含量的37.4%,20.1%,10.0%和6.7%。同位素峰形校正检索技术在低分辨率质谱上可对化合物的相对分子质量实现精确测量,从而为低分辨率四极杆质谱确定化合物的元素组成和解析化合物结构提供了重要依据,同时也为芝麻油的成分分析提供了新的技术手段。     

Study on Volatile Chemicals as Spoilage Indexes of Salmon by HS-SPME-GC-MS Technique during Non-Frozen Storage

Freshness is the most fundamental and important factor to assess raw fish quality. The purpose of our study was to determine the potential spoilage indexes of salmon during non-frozen storage by using headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS). More than 300 volatile compounds in salmon were detected when sensory scores declined gradually following the quality changes of salmon at different temperatures. And there were 27 and 31 compounds that showed concentration variations when stored at 4 °C and 25 °C, respectively. Among them, the contents of 1,3-di-tert-butylbenzene, acetic acid, and 3-methyl-1-butanol increased significantly in the later storage period and were in accordance with the salmon’s qualities. The present study provides valuable information on the volatile chemical spoilage indexes that are closely related to the freshness of salmon, which may provide an efficient alternative way for quality evaluation of salmon.     

Optimization of Fish Quality by Evaluation of Total Volatile Basic Nitrogen (TVB-N) and Texture Profile Analysis (TPA) by Near-Infrared (NIR) Hyperspectral Imaging

Hyperspectral images contain both spectral and spatial image information and were investigated to characterize the freshness of fish. However, most studies of this application have focused on spectral signals rather than image features. The goal of this work was to investigate the ability of spectral and image textural variables for predicting the chemical and physical qualities of fish, respectively, and to optimize the variables for the specific quality determination. The chemical (total volatile basic nitrogen, TVB-N) and physical (texture profile analysis, TPA) properties were investigated. Partial least square (PLS) was applied to develop fish quality prediction models with the spectral and textural variables from the hyperspectral images. The results showed that the TVB-N content of fish fillets was accurately predicted using the spectra. Meanwhile, the TPA parameters were determined through the image textural features with high accuracy, which indicated image textural features were highly related with the TPA parameters. Moreover, spectral and textural features were also extracted from fish eyes and gills and were further used to predict the intact fish quality, taking advantage of the freshness sensitivity of the eyes and gills. The results illustrate that spectra from fish eyes and gills are a potential tool to predict the TVB-N content and TPA parameters for intact fish.     

顶空-固相微萃取法与水蒸气蒸馏法提取沙棘挥发油组分的比较研究

优化了顶空-固相微萃取法(HS-SPME)提取沙棘挥发性成分的条件,并采用气相色谱-质谱联用技术(GC-MS)分别对HS-SPME法和水蒸气蒸馏法(SD)的提取物进行分析。结果显示,在萃取温度为70℃,萃取时间为50 min,解吸时间为7 min,平衡时间为20 min条件下,HS-SPME法鉴定出76种组分,占挥发性物质总量的90.19%,主要成分为酯类、醛类和酮类;而SD法提取物共鉴定出56种组分,占挥发性物质总量的91.98%,主要成分为酯类。2种方法共有组分为20种。两种方法提取的沙棘挥发油组分的种类及含量差异较大,HS-SPME法更适合沙棘挥发性组分的快速检测。     

气相色谱-质谱联用结合化学计量学方法分析光照对鱼腥草挥发性成分的影响

采用色谱-质谱联用技术结合化学计量学方法对不同光照生长条件的鱼腥草挥发性成分进行分析。水蒸气蒸馏法提取鱼腥草挥发油,气相色谱-质谱进行分析。色谱指纹图谱结合主成分分析与相似度评价以探究不同光照挥发油成分的异同。直观推导式演进特征投影法(Heuristic evolving latent projections,HELP)分辨重叠色谱峰,NIST标准质谱库结合相关文献进行定性,峰面积归一化法定量,t-检验比较不同光照组成分含量间是否有显著性差异。3种光照下的鱼腥草挥发油指纹图谱存在一定的共性和差异,共鉴定出33种化合物,共有化合物26种。随着光照强度的减少,单萜类化合物含量减少,非萜类含量增多,倍半萜类变化不大。癸酰乙醛和甲基正壬酮在全光照组的含量明显低于遮光组的含量。研究结果表明,适度的遮光有利于鱼腥草挥发性有效成分含量的提高,鱼腥草药材挥发性成分种类及含量与生长条件密切相关。     

三种西藏香茶菜挥发油化学成分的研究

唇形科植物香茶菜广泛分布于全国各地,民间一直用作抗菌消炎药使用,近年来发现,香茶菜属植物有抑制肿瘤和抗癌活性,其活性成分是二萜。我们对采自西藏的3种香茶菜的挥发油进行了GC/MS分析。从小叶香茶菜[Rabdosia Parrifolia(Batal)Hara; Litte leaf Rabdosia]油中分出84个峰,鉴定了27个,占总面积的60％;从川藏香茶菜(Rabbosia Pseudo-irrarata C.Y.Wu,Szechwan-Tibet Rabdosia)油中分出72个峰,鉴定了39个,占总面积的82.5％;从皱叶香茶菜[Rabdosia rugosa(Wcll.)Hara,Wrinkted leaf Rabdosia]中分出了90个峰,鉴定了39个,占总面积的62.1％。3种香茶菜的分析尚未见报道。     

10°锥角台锥型液相色谱柱尺寸等比例放大和柱内谱带流型的可视化研究

摘要利用改进的可视化装置, 研究了10°锥角的台锥型液相色谱柱内的谱带流型与柱参数变化的关系. 将有机玻璃柱管加工成内圆台外方型的一体结构, 选择折射率一致的色谱固定相硅胶和流动相环己烷, 使整个色谱柱成为高度清晰的透明体, 能直接观察柱中彩色样品谱带的动态三维流型. 研究结果表明, 在实验条件范围内, 流动相流速对谱带流型无影响, 填料的形状和性质对塞子状流型有一定程度的影响. 比较了柱长为5cm和等比例放大后柱长为10cm锥型柱内的流型, 发现放大后的锥型柱内仍然保持塞子状流型, 总柱效等比例增加. 表明继续按比例放大成为工业规模色谱柱后仍能保持塞子状流型.     

Elucidation of Analytical–Compositional Fingerprinting of Three Different Species of Chili Pepper by Using Headspace Solid-Phase Microextraction Coupled with Gas Chromatography–Mass Spectrometry Analysis,and Sensory Profile Evaluation

The aim of the present study was to determine the volatile compounds of three different species of chili peppers, using solid-phase microextraction (SPME) methods in combination with gas chromatography–mass spectrometry (GC-MS). The detection of marker aroma compounds could be used as a parameter to differentiate between species of chili peppers for their detection and traceability in chili pepper food. The sensorial contribution was also investigated to identify the predominant notes in each species and to evaluate how they can influence the overall aroma. Three different pepper species belonging to the Capsicum genus were analyzed: Chinense, Annuum, and Baccatum. A total of 269 volatile compounds were identified in these species of chili peppers. The Capsicum annum species were characterized by a high number of acids and ketones, while the Capsicum chinense and Capsicum baccatum were characterized by esters and aldehydes, respectively. The volatile profile of extra virgin olive oils (EVOOs) flavored with chili peppers was also investigated, and principal component analysis (PCA) and hierarchical cluster analysis (HCA) of the volatile profiles were demonstrated to be a powerful analytical strategy for building a model that highlights the potential of a volatile characterization approach for use in evaluating food traceability and authenticity.     

中药药对的化学成分研究川芎-赤芍挥发油的GC/MS分析

中药药对是复方的最小组成单位,具有中药配伍的基本特点. 药对化学是复方化学的核心内容. 联用色谱和化学计量学方法为中药复杂体系的分离与分辨提供了强有力的工具. 采用GC-MS法分离测定中药药对川芎-赤芍、 单味药川芎和赤芍的挥发油成分,并对其中的重叠色谱峰采用化学计量学解析方法(CRM)进行分辨,得到药对和各单味药的纯色谱曲线和质谱图,药对川芎-赤芍、 单味药川芎和赤芍分别分辨出82,78和57个色谱峰,通过质谱库对分辨的纯组分进行定性,分别得到61,52和33个定性结果,占总含量的90.18%,95.14%和95.82%.