不同产地来源山药气-质联用图谱的比较研究

目的:比较不同产地山药内在化学成分的差异,为判定山药的产地来源提供可靠的方法。方法;气-质联用法分析不同产地山药正己烷提取液。结果:实验结果显示,不同产地山药的正己烷提取液中的化学成分存在着显著的差异。结论:气-质联用法可以作为判别山药产地或品种的可靠方法。

3,5-二叔丁基-4羟基苯基丙酸甲酯生产中的杂质分析及质量控制

建立了测定3,5-二叔丁基-4-羟基苯基丙酸甲酯(简称3,5-甲酯)及其中杂质3-(3-叔丁基-4羟基)苯丙酸甲酯(简称3-甲酯)含量的气相色谱-气质联用色谱分析方法,系统分析了其生产过程中3-甲酯产生的原因以及其对产品质量的影响。3-甲酯是在高温高真空的精馏塔中由3,5-甲酯脱掉一个叔丁基生成,该物质影响3,5甲酯的主含量和产品颜色,最终影响由3,5-甲酯合成的其他抗氧剂的产品质量。通过控制精馏塔的进料速度和温度参数可降低3-甲酯的含量,提升3,5-甲酯产品质量。

芍花提取物SPME-GC/MS成分分析及抗炎抗氧化活性研究

目的采用超临界CO_(2)萃取法对芍花进行提取,得到芍花提取物,研究芍花提取物的主要化学成分以及其抗炎、抗氧化活性。方法采用固相微萃取气-质色谱联用法(SPME-GC/MS)对芍花提取物的主要成分进行分析;利用噻唑蓝法(MTT法)考察芍花提取物对脂多糖(LPS)致炎RAW264.7巨噬细胞的抗炎作用,同时对RAW264.7巨噬细胞分泌NO的含量进行测定;通过MTT法考察芍花提取物对H_(2)O_(2)诱导的RAW264.7巨噬细胞细胞损伤的保护作用。结果通过SPME-GC/MS分析,从芍花提取物中分离鉴定了15种主要物质,其中D-樟脑含量最高,其含量为27.56%,此外芍花提取物中还含有丹皮酚、苯甲酸、4-甲氧基苯酚等成分;芍花提取物能够增加LPS诱导的RAW264.7巨噬细胞致炎模型的细胞存活率,降低细胞中NO含量;芍花提取物对受H_(2)O_(2)氧化损伤的RAW264.7巨噬细胞具有一定保护作用。结论芍花提取物对LPS引起的RAW264.7巨噬细胞炎症损伤及H_(2)O_(2)导致的RAW264.7巨噬细胞氧化损伤具有一定的抗炎、抗氧化活性,这可能与芍花提取物中鉴别出的D-樟脑、丹皮酚及苯甲酸等活性成分有关。

微波-超声波协同提取芍花精油工艺研究及成分分析

目的:研究芍花精油的微波-超声波协同辅助提取工艺。方法:以提取率为指标,通过单因素与正交试验确定芍花精油的最佳提取工艺,运用气-质联用色谱技术(GC-MS)对芍花精油进行成分分析,并用色谱峰面积归一化法测定各组分的相对百分含量。结果:芍花精油最佳提取工艺为微波时间90 s、超声时间30 min、料液比1∶6(g/ml)、提取时间3 h;共鉴定了芍花精油成分22种,除了已报道的烷烃类和醇类,还发现了酮类、酚类、醛类及烯类等,其中烷烃类占67.59%,酮类成分占10.49%、烯类成分占9.28%等。结论:微波-超声波协同辅助提取法能有效提取芍花精油成分,同时论证了不同方法提取的芍花精油其化学成分存在差异,也为建立一套完整的芍花精油成分提供理论依据。

麦冬脂溶性成分的GC-MS研究

目的:对麦冬药材的脂溶性成分进行气质联用成分分析。方法:采用气质联用技术对中药麦冬的三氯甲烷部位进行化学成分分析,通过质谱棒图分析及NIST98谱库检索,确定化合物结构。结果:确定了气质联用分析条件,从麦冬块根的三氯甲烷部位测得32个脂溶性成分。结论:该方法解析了麦冬低极性部位的化学成分,为全面反映麦冬的化学成分提供依据。

野野村放线菌Nonomuraea sp.ATCC 39727脂肪酸的GC-MS分析

利用气相色谱-质谱联用技术(GC-MS)对产脂糖肽抗生素A40926的Nonomuraea sp.ATCC39727的细胞脂肪酸进行了分析,共检出12种脂肪酸,主要脂肪酸包括iso-C16:0、n-C16:1△7、n-C16:0、n-C18:1△9脂肪酸,其中n-C16:0脂肪酸含量最高,达到39.563%。结果表明,Nonomuraeasp.ATCC39727细胞中以偶数碳的直链脂肪酸为主,而奇数碳脂肪酸(C15、C17)含量较低。

Chemical Compositions of Volatile Oil from Fruiting Body of Armillaria luteo-virens

The chemical compositions of volatile oil from fruiting body of Armillaria luteo-virens in Qinghai Province were firstly analyzed with GC-MS and its relevant compositions were detected by calculating chromatographic peak area with normalized method. 21 peaks were separated and 13 compositions were identified which were mainly unsaturated fatty acids, taking 97.1% of the total volatile oil.

Simultaneous Determination of 8 Pesticide Residues in Green Tea Based on Gas Chromatography-mass Spectrometry

To improve pesticide residues detection efficiency in tea, simultaneous de- termination of eight pesticide residues in green tea was developed based on gas chromatography-mass spectrometry （GC-MS）. The results showed that, - detected by the GC-MS under following conditions： acetonitrile as extraction and elution solvent, activated carbon and PSA tandem column as the stationary phase, elution volume of 12 ml the relationship between peak area and concentration of each residue （ametryn in the range of 0-100 pg/L, napropamide in the range of 0-10 000 gg/L, other pesticides in the range of 0-1 000 tJg/L） were linearly related, and their corre- lation coefficients were all greater than 0.999. The recovery rate the pesticides added to tea sample at legal concentration limits ranged from 73.6% to 116.8%, and the relative standard deviation from 1.47% to 15.58%. The new method we de- veloped is sensitive, specific and anti-interference, and thus provides test basis for the development of pesticide matrix reference materials in tea.

阿萨姆及大吉岭红茶香气组分与农业措施和加工的关系

前言加工的目的是为了取得理想的感官品质,因此,很有必要弄清楚各种组份对感官品质的贡献及在何种条件下形成这些化合物的。由相对比较嫩的鲜叶所制的红茶具有一定的青气,这主要是由反-2-已烯醛,顺-3-己烯醇和己烯醛类等物质所造成的,诸化台物是由亚油酸和亚麻酸的酶性氧化作用形成的。

Diethylstilbestrol in Fish Tissue Determined Through Subcritical Fluid Extraction and with GC-MS

As the key point in sex hormone analysis, sample pre-treatment technology has attracted scientists' attention all over the world, and the development trend of sample preparation forwarded to faster and more efficient technologies. Taking economic and environmental concerns into account, subcritical fluid extraction as a faster and more efficient method has stood out as a sample pre-treatment technology. This new extraction technology can overcome the shortcomings of supercritical fluid and achieve higher extraction efficiency at relatively low pressures and temperatures. In this experiment, a simple, sensitive and efficient method has been developed for the determination of diethylstilbestrol(DES) in fish tissue using subcritical 1,1,1,2-tetrafluoroethane(R134a) extraction in combination with gas chromatography-mass spectrometry(GC-MS). After extraction, freezing-lipid filtration was utilized to remove fatty co-extract. Further purification steps were performed with C_(18) and NH_2 solid phase extraction(SPE). Finally, the analyte was derived by heptafluorobutyric anhydride(HFBA), followed by GC-MS analysis. Response surface methodology(RSM) was employed to optimizing the extraction condition, and the optimized was as follows: extraction pressure, 4.3 MPa; extraction temperature, 26℃; amount of co-solvent volume, 4.7 m L. Under this condition, at a spiked level of 1, 5, 10 μg kg^(-1), the mean recovery of DES was more than 90% with relative standard deviations(RSDs) less than 10%. Finally, the developed method has been successfully used to analyzing the real samples.

Discrimination of Acori Tatarinowii Rhizoma from two habitats based on GC-MS fingerprinting and LASSO-PLS-DA

This study is intended to explore the chemical differences of Acori Tatarinowii Rhizoma （ATR） samples collected from two habitats, Sichuan and Anhui provinces, China. Gas chromatography-mass spectrometry （GC-MS） was applied to establishing the quantitative chemical fingerprints of ATRs. A total of 104 volatile compounds were identified and quantified with the information of mass spectra and retention index （RI）. Furthermore, least absolute shrinkage and selection operator （LASSO）, a sparse regularization method, combined with subsampling was employed to improve the classification ability of partial least squares-discriminant analysis （PLS-DA）. After variable selection by LASSO, three chemical markers,β-elemene, α-selinene and α-asarone, were identified for the discrimination of ATRs from two habitats, and the total classification correct rate was increased from 82.76% to 96.55%. The proposed LASSO-PLS-DA method can serve as an efficient strategy for screening marked chemical components and geo-herbalism research of traditional Chinese medicines.

Evaluation of Pesticide Residues in Mango by a Multi-residue Analysis and GC/MS Triple Quadrupole

Mango fruit has a great national and international market, and Brazilian production is 1,900 thousand tons/year exporting to North America and Europe. However, the loss could occur during the production when it is affected by pests and climate conditions, so the increased use of chemical substances and their presence should be monitored. A task for governmental agencies, producers and food sales, attending the sanitary barriers requirements, is to distribute food free from contaminants, so laboratories involved in this type of work usually employ multi-residues analysis. The objective of this study was to evaluate the presence of pesticide residues in mango using QuEChERS method and mass spectrometry technique. Positive samples were compared with Brazilian maximum residues level （MRL） and the health risk exposure was evaluated using the acute dietary intake （ADI） parameter. A total of 20 samples were collected from January to March, in Sao Paulo city markets. The recoveries were in the range of 70% to 120%, and standard deviation was below 20%. The category of pesticides not permitted for the crop were found in l0 samples; eight samples presented pesticides below MRL and two samples above MRL for the fungicide procloraz. The ADI values were below 20% of ADI for an adult and the worst case was dimethoate with 69% of ADI for children. The time spent in monitoring studies and the viability of method chosen must be considered by pesticide residues laboratories during routine analysis of food quality control.

Lipid Oxidation and Fatty Acid Composition in Salt-Dried Yellow Croaker(Pseudosciaena polyactis) During Processing

Lipid oxidation in salt-dried yellow croaker(Pseudosciaena polyactis) was evaluated during processing with commonly used analytical indices, such as the peroxide value(POV), the thiobarbituric acid reactive substances(TBARS) value, and oxidative-relative lipoxygenase(LOX) activity. Additionally, fatty acids were analyzed using gas chromatography-mass spectrometry. Both POV and TBARS increased significantly(P < 0.05) at the rinsing stage. POV reached its peak value of 3.63 meq O_2 per kg sample at the drying stage, whereas TBARS constantly increased from 0.05 to 0.20 mg MDA per kg sample. Processing of salt-dried yellow croaker had an extremely significant(P < 0.01) effect on LOX activity. Twenty-six fatty acids were identified. Combined eicosapentaenoic acid(EPA; C20:5n3) and docosahexaenoic acid(DHA; C22:6n3) content varied between(19.20 ±0.37) mg g^(-1) and(23.45 ± 1.05) mg g^(-1). The polyunsaturated fatty acid/saturated fatty acid(PUFA/SFA) ratio in yellow croaker was 0.73–1.10, and the n-6/n-3 PUFA ratio was approximately 0.13–0.20. The contents of most fatty acids varied significantly(P <0.05) during the different processing stages, and these differences were caused by lipid oxidation. C18:0, C16:1n7, C19:0, and C22:6n3 showed clear changes in principle component one of a principle components analysis. These fatty acids are potential markers for evaluating lipid oxidation in fish muscle because there was a significant correlation between these markers and TBARS and LOX activity(P < 0.05) with Pearson's coefficients > 0.931.

Assessment of Triazine Herbicides in Soil by Microwave-assisted Extraction Followed by Gas Chromatography Coupled to Mass Spectrometry Detection

An alternative and fast method for the analysis of a mixture of nine triazines herbicides in soil is presented. The method is based on MAE （microwave-assisted extraction） of herbicides using ethyl acetate as extractant. The economy in the use of solvents coupled with the decrease in extraction time and lower power consumption make MAE a technique that meets the principles of green chemistry. MAE operational parameters, extraction time, mass of the sample and extraction temperature, were optimized by RSM （response surface methodology）. Determination of analytes was completed using gas chromatograph coupled to mass spectrometry detection. The selected triazines could be efficiently extracted by the solvent at 80 ℃ for 10 min, with 80% output of maximum power. When the optimized method was applied to analysis samples, the recoveries of analytes ranged from 81.8 to 106.0% and relative standard deviations were lower than 8.41%. The method is stable and reasonable, which can be used for the determination of ninetriazine herbicides residues in soil.

Pyrolysis of Agroindustrial Residues of Coffee, Sugarcane Straw and Coconut-Fibers in a Semi-pilot Plant for Production of Bio-oils： Gas Chromatographic Characterization

Microbial, vegetal or animal organic matter, which has potential to be transformed into energy, is considered biomass. Among the various alternative energy sources, biomass is the only one with the possibility of generating a class of substances of interest for fine chemistry （ketones, aldehydes, alcohols, phenols, etc.）. From biomass, it is possible to produce bio-oil using pyrolysis, a thermodegradation process. The quality of the bio-oil depends on the process conditions （pyrolysis temperature, heating temperature, etc.） and biomass used. In this paper, the pyrolysis （using a fixed bed reactor） of three biomasses （coconut fiber, coffee grounds and sugar cane straw） is studied. The results indicated that the bio-oil yields for all biomass were similar, approximately 37%. The chemical profile obtained by gas chromatography coupled with mass spectrometry （GC/qMS） showed high amounts of fatty acids in the coffee grounds bio-oil and aliphatic and aromatic hydrocarbons in coconut fiber bio-oil, whereas guaiacols were the predominant components of the sugar cane straw bio-oil.

Study on GC-MS fingerprint of petroleum ether fraction of Shenqi Jiangtang Granules

Objective To establish gas chromatography-mass spectrometry(GC-MS)fingerprint method for the petroleum ether fraction of Shenqi Jiangtang Granules(SQJTG)and evaluate the product quality.Methods The GC-MS fingerprint of petroleum ether fraction of SQJTG was established by GC-MS,and the chemical components corresponding to the fingerprint peaks were structurally identified on NIST2014.The batch consistency of SQJTG products was evaluated based on the chemical composition of petroleum ether parts by using fingerprint similarity evaluation and Principal components analysis(PCA)technology.At the same time,Hotelling's T2 and DMODX statistics are used to set the control range for the quality of different batches of products.Results Twenty-two components were identified from the petroleum ether part of SQJTG,accounting for 60.94%of the total components separated.The similarity of fingerprints of petroleum ether parts of 24 batches of SQJTG was greater than 0.95.The PCA of 24 batches of samples were all under the control limits of Hotellin’s T2 and DMODX statistics,indicating that the petroleum ether parts of different batches of SQJTG were consistent.Conclusion The developed GC-MS fingerprint method can be used to evaluate the quality of SQJTG.

葎草鲜品不同部位的挥发油成分及含量

为探明葎草鲜品中雌花、雄花、叶和茎中挥发油的化学成分组成及各成分的相对含量,采用固相微萃取技术和GC-MS法对其化学成分进行提取及分析鉴定。结果表明:在葎草的雌花、雄花、叶和茎中分别鉴定出41、55、56和20个化学成分,其相对含量分别占各部位挥发油总量的97.034%、96.432%、78.753%和53.187%;4个部位具有相同的挥发性化学成分12个,主要成分均含有β-石竹烯、(E)-β-金合欢烯、δ-杜松烯、环氧石竹烯等。

无患子籽仁油的提取工艺及其成分分析

为给无患子籽仁油的开发利用提供理论依据,以无患子籽仁为原料,采用正交试验方法,就提取籽仁油的各主要工艺参数的变化对籽仁油提取得率的影响情况进行了试验;并采用GC-MS分析法,对无患子籽仁油的成分进行了分析。试验结果表明,较优的提取工艺条件为:提取次数2次,提取温度80℃,料液比为1∶5,提取时间2 h,得率达41.63%。检测结果表明:无患子籽仁油中含有棕榈酸、硬脂酸、油酸、亚油酸、花生酸、亚麻酸、二十碳烯酸、山嵛酸、芥子酸等11种脂肪酸成分,其中C_(16)~C_(20)的脂肪酸占97%,不饱和脂肪酸含量在83%以上,油酸和亚油酸的含量均达到54%以上;无患子籽仁油的酸值为2.46 mg·g^(-1),皂化值为202.46 mg·g^(-1),碘值为0.985 3 g·g^(-1);无氰甙成分。

白松木成型燃料热解焦油性能及成分研究

通过与煤焦油性能对比分析发现,白松木成型燃料热解焦油的含水量及氧元素含量较高,N、S含量和热值很低,酸值较高,具有较强的腐蚀性。采用傅里叶变换红外光谱仪对松木焦油进行官能团结构分析知其含有—OH、—CO以及芳香族基团。对不同气氛下焦油的热重分析表明,常温下焦油的保存期对其化学组成影响很小。在空气或氮气氛下300℃以下焦油的热重曲线基本吻合,从150℃开始热解速率加快,而后在空气气氛下400℃焦油热解多出一个燃烧阶段,且残余量很小。利用色谱-质谱联用技术分析出热解焦油的41种主要成分,总相对百分含量为79.25%,其中3-羟基-4-甲氧基甲苯(9.79%)、4-乙基愈创木酚(8.43%)、愈创木酚(6.83%)等相对含量较高。

3种香薷属植物叶花果挥发性成分比较分析

【目的】为了解北京地区3种乡土香薷属(Elsholtzia)植物的挥发性成分,探究不同香薷属植物各部位的挥发性成分差异,【方法】采用顶空固相微萃取-气相质谱联用(HS-SPME-GC-MS)法对北京地区分布的木本香薷(E.stauntoni)、海州香薷(E.splendens)和香薷(E.ciliata)的叶、花、果的挥发性成分进行比较分析。【结果】从3种香薷属植物中共检测到主要挥发性成分51种,有萜烯类、酯类、醇类、烷类、酮类、酸类、酚类、醛类和呋喃9大类,其中木本香薷中检测出24种,海州香薷中检测出34种,香薷中检测出22种,3种香薷属植物的共有挥发性成分中含量较高的为β-石竹烯和α-法尼烯。【结论】各种挥发性成分在3种香薷属植物的叶、花和果之间差异明显,2,3,5,6-四甲基苯酚、香薷酮和罗勒烯分别在木本香薷、海州香薷和香薷中有较高含量。