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1.
采用气相色谱-质谱法(GC／MS)分析了香蕉叶中挥发油的化学成分，鉴定了22个化合物，主要成分是十七烷、二十一烷、二十八烷、三十四烷、10-甲基-十九烷、3，7，11，15-四甲基十六烷、十五烷基环己烷等，占整个挥发性物质的61．45％；其次是2，6-二叔丁基4-甲基苯酚，占总挥发性物质的14．74％。确认了C20H42同分异构体。 相似文献
2.
【目的】分析珍珠龙胆石斑鱼背、腹部肌肉的营养成分与挥发性风味成分。【方法】采用顶空固相微萃取与气相色谱-质谱联用技术检测鱼肉挥发性风味物质,用常规分析法检测鱼肉氨基酸及脂肪酸组成。【结果】珍珠龙胆石斑鱼含肉率达到71.03%±3.88%,鱼鳞与皮质量分数高达9.60%±1.67%。背、腹部肌肉的蛋白质质量分数(干基)分别为85.19%和77.47%,脂肪质量分数分别为6.44%和12.00%,必需氨基酸占总氨基酸质量分数均为0.45;背、腹部肌肉第一限制性氨基酸均为缬氨酸,氨基酸评分(AAS)分别为86和81,氨基酸指数分别为80.06和72.61,均为赖氨酸含量最高,氨基酸评分(AAS)分别为156和140;背部肌肉中5种鲜味氨基酸总量(7.26%)较腹部(7.09%)略高,不饱和脂肪酸分别占肌肉脂肪酸总量的60.11%和45.54%,EPA+DHA的含量是腹部肌肉的11.5倍,质量分数达20.42%,ω-3/ω-6 PUFA为9.56;背、腹部肌肉分别检出挥发性风味物质50与52种,腹部肌肉中醇类物质含量最高,质量分数达60.25%,其不饱和醇类与醛类对其肌肉的总体风味起重要贡献。【结论】珍珠龙胆石斑鱼是一种高蛋白、低脂肪、富含赖氨酸、精氨酸、EPA和DHA的优质海产经济鱼种,其背部肌肉蛋白质营养价值高于腹部,是优质的ω-3不饱和脂肪酸的食物来源;背、腹部肌肉挥发性风味物质含量丰富,腹部肌肉的鲜味优于背部肌肉。 相似文献
3.
《地球科学与环境学报》2016,(2)
依据珠江口盆地惠州凹陷不同类型原油样品中各类生物标志物分布与组成特征的分析结果,可以将其划分为煤成油和湖相油两大类。以HZ9-2-1井为代表的煤成油表现出强烈的姥鲛烷优势,C19~C_(26)三环萜烷系列相对丰度呈现阶梯状依次降低,C_(24)四环萜烷相对丰度远高于C_(26)三环萜烷,藿烷系列C_(29)降藿烷和C31升藿烷较为丰富,新藿烷(Ts和C_(29)Ts)含量很低,甾烷组成中C_(29)规则甾烷和重排甾烷占绝对优势,这与典型煤成油的分子地球化学特征一致。湖相油中姥鲛烷优势较弱,C_(19)~C_(26)三环萜烷系列呈现以C_(21)为主峰的正态分布,C_(24)四环萜烷丰度与C_(26)三环萜烷丰度相当,新藿烷和重排藿烷含量中等,伽马蜡烷含量极低,2-甲基藿烷与C_(30)4-甲基甾烷十分丰富且存在正相关关系。它们可以作为鉴别研究区原油成因类型的主要依据。 相似文献
4.
利用地球化学分析手段,对西湖凹陷黄岩构造带、平北地区以及宁波构造带的16个轻质油样品进行了分析。原油中富含反映陆源高等植物输入的生物标志化合物,尤其是源于被子植物、裸子植物及蕨类植物的三环、四环二萜类及其芳构化产物,而反映水生低等植物输入的生物标志化合物含量较低。不同构造带间原油中这些化合物的分布特征具有明显差异,如异海松烷/nC20、异海松烷/（异海松烷+16β（H）扁枝烷）、1,2,5-三甲基萘/1,3,6-三甲基萘、1,7-二甲基菲/（惹烯+1,7-二甲基菲）等。这些差异指示了宁波构造带与平北地区原油裸子植物输入较多,蕨类植物及被子植物输入较少,而黄岩构造带原油蕨类植物输入较多,被子植物与裸子植物较少的特点。研究中利用全油色谱-质谱将原油饱和烃与芳烃组分建立联系,提出（异海松烷+1,7-二甲基菲）/（惹烯+16β（H）扁枝烷）作为反映西湖凹陷轻质原油生源构成的指标,而该参数与全油碳同位素值的正相关关系证明了裸子植物树脂对西湖凹陷轻质油的重要成烃贡献。 相似文献
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【目的】探究最佳即食红毛藻加工工艺。【方法】通过正交试验确定最佳调味配方;以感官评分为主要指标,辅以电子鼻分析,在单因素的基础上运用响应面法优化即食红毛藻的最佳烘烤工艺,并采用气相色谱-质谱联用技术检测成品的挥发性风味成分。【结果与结论】最佳调味配方为(质量分数)食糖4%、食盐2%和味精1.5%,最优烘烤工艺为烘烤时间25 min、烘烤温度107℃、样品厚度3.5片厚。经过烘烤后的红毛藻挥发性物质主要是醛类、烷烃类和芳香族等。 相似文献
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【目的】研究香港牡蛎加热处理前后的挥发性成分变化及其变化原因。【方法】采用顶空固相微萃取与气相色谱-质谱联用技术(solid phase micro-extraction gas chromatographmass spectrometer,SPME-GC/MS)分析香港牡蛎肉挥发性风味成分,结合感觉阈值,利用相对气味活度值(relative odour active value,ROAV)确定牡蛎熟制前后的主要挥发性风味成分,描述主要挥发性风味成分的气味特征并分析其生成途径。【结果与结论】加热处理前后牡蛎的挥发性成分发生明显变化,从鲜牡蛎和熟制牡蛎中分别鉴定出101种和107种风味物质,主要物质有醛、醇、酮、酸、烃、酯、酚类等,对气味影响最大的醛类化合物由熟制前的26种增加到熟制后的30种,相对含量却由熟制前的33.25%减少到熟制后的14.65%,酸类化合物由熟制前的7种增加到熟制后的19种,相对含量却由熟制前的8.82%增加到熟制后的32.98%。熟制后酯类化合物在种类和含量上都有所增加。 相似文献
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分子标志物作为反映有机质热演化信息的重要载体，具有随温度升高发生侧链断裂、异构化和芳构化的性质，部分对温度增高具有良好响应的分子标志物参数具备表征成熟度的基本条件。根据分子标志物在热演化中的结构变化规律及其有效性和适用性，甄选出可用于有机质成熟度评价的多种分子标志物参数:姥鲛烷异构化指数（ＰＩＲ）、锥满烷指数（ＤＨＲ）（８β（Ｈ）－锥满烷／８β（Ｈ）－高锥满烷）、藿烷（Ｔｓ／（Ｔｍ＋Ｔｓ））、重排甾烷（２０Ｓ／（２０Ｓ＋２０Ｒ））、金刚烷、烷基萘、甲基菲以及烷基二苯并噻吩（ＤＢＴｓ）。鉴于不同参数优点与适用范围的差异性，多参数联合使用可提高评价的准确性。研究结果表明:Ｃ２９甾烷参数与单芳甾烷联合使用适用于Ｒｏ≤０．７％的有机质成熟度评价，Ｔｓ／（Ｔｍ＋Ｔｓ）、单芳甾烷、甲基菲比值（ＭＰＲ）、甲基菲指数（ＭＰＩ）、ＤＨＲ 与甲基二苯并噻吩分布指数（ＭＤＢＩ）的联合使用可评价０．７％≤Ｒｏ≤１．３％范围内的有机质成熟度，ＭＰＩ、ＤＨＲ、烷基萘指数、甲基双金刚烷成熟度指标（ＩＭＤ），即４－ＭＤ／（１－ＭＤ＋３－ＭＤ＋４－ＭＤ）和 ＰＩＲ 的联合使用可评价１．３％≤Ｒｏ≤２．０％范围内的有机质成熟度，当 Ｒｏ≥２．０％时，则仅有 ＰＩＲ具有有效性。 相似文献
8.
中国69个城市地下水挥发性卤代烃污染检测与特征研究 总被引：2，自引：0，他引：2
为了初步掌握中国主要城市地下水挥发性卤代烃污染状况和特征,在中国69个城市开展了地下水挥发性卤代烃污染检测与特征研究,采集地下水样品791组,采样井均为工农业生产和生活饮用水水井;依据US EPA 8260B检测方法,采用气相色谱/质谱联用分析仪器(P&T-GC/MS),分析和测试了氯仿、四氯化碳、1,1,1-三氯乙烷、三氯乙烯、四氯乙烯和二氯甲烷等15种挥发性卤代烃的质量浓度。结果表明:在791组地下水样品中,有406组样品至少有一种挥发性卤代烃组分被检出,检出率为51.33%;各组分中,氯仿的检出率最高,为20.35%,其他组分的检出率为0.25%～5.06%;氯乙烯在所有样品中均未检出;有13组样品的单项组分超标,超标率为1.64%;超标率由高到低分别为四氯化碳(0.76%)、氯仿(0.25%)、1,2-二氯乙烷(0.25%)、三氯乙烯(0.13%)、1,1,2-三氯乙烷(0.13%)、1,2-二氯丙烷(0.13%);超标井均为非供水水源地水井。检测与研究结果表明:中国主要城市地下水挥发性卤代烃污染物检出率较高,检测的69个城市中71%的城市至少有一种挥发性卤代烃被检出,且潜水的检出率高于承压水,但总体超标率较低。 相似文献
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埃达克岩与Gu、Au等金属元素的富集关系密切,并对深部造山构造作用具有重要的指示意义。受到碰撞造山作用,在西藏地区发育了一条成矿潜力巨大的斑岩铜矿带,甲玛铜多金属矿床就位于该铜矿带的东段。对甲玛矿床中酸性侵入岩进行地球化学测试分析,结果显示:SiO_2(≥56%)、高Al_2O_3(≥15%)、低MgO(3%),Na_2O含量大于2.3%,K_2O含量大于2.1%,K_2O/Na_2O为0.6~1.2;稀土元素和微量元素结果显示高Sr(400×10~(-6)),低Yb(1.9×10-6)、低Y(15×10~(-6)),LREE富集,HREE亏损,无负Eu异常,具有埃达克岩地球化学特征,属于C型埃达克岩,为加厚下地壳或上地幔物质部分熔融所形成。 相似文献
10.
当前我国尚无菱镁矿、蛇纹岩、高品位碲金矿化学成分标准物质,国外相应标准样品存在定值元素少,且主成分含量不成系列,不能满足地质行业对菱镁矿、蛇纹岩、碲金矿标准物质的迫切需求。该文研制了菱镁矿、蛇纹岩、碲金矿化学成分标准物质共12个,将采自典型矿区的样品按照常规球磨方式粉碎混匀,采用电感耦合等离子体发射光谱法(ICP-AES)和电感耦合等离子体质谱法(ICP-MS)进行均匀性和稳定性检验,选择11家有资质的实验室,采取经典分析方法与现代仪器分析方法相结合的方式,选用2种以上不同原理的准确度高的可靠方法对该标准物质联合定值,依照JJF 1343—2012和一级标准物质技术规范,12个化学成分标准物质给出了30项主、微量元素的认定值和不确定度。其中,菱镁矿Mg O的含量范围为43.64%~81.26%,蛇纹岩Mg O的含量范围为23.73%~43.09%,高品位碲金矿Au的含量范围为19.6×10~(-6)~32.1×10~(-6)、Te的含量范围为51×10~(-6)~83×10~(-6),基本涵盖我国菱镁矿、蛇纹岩、高品位碲金矿的矿物类型,能够满足菱镁矿、蛇纹岩、碲金矿勘查、评价和开发的需求。 相似文献
11.
The impact of meso-scale eddies on the Subtropical Mode Water in the western North Pacific 总被引：1，自引：0，他引：1
Based on the temperature and salinity from the Argo profiling floats and altimeter-derived geostrophic velocity anomaly (GVA) data in the western North Pacific during 2002–2011, the North Pacific Subtropical Mode Water (NPSTMW) distribution is investigated and cyclonic and anti-cyclonic eddies (CEs and AEs) are constructed to study the influence of their vertical structures on maintaining NPSTMW. Combining eddies identified by the GVA data and Argo profiling float data, it is found that the average NPSTMW thickness of AEs is about 60 dbar, which is thicker than that of CEs. The NPSTMW thicker than 150 dbar in AEs accounts for 18%, whereas that in CEs accounts for only 1%. About 3377 (3517) profiles, which located within one diameter of the nearest CEs (AEs) are used to construct the CE (AE). The composite AE traps low-PV water in the center and with a convex shape in the vertical section. The ‘trapped depth’ of the composite CE (AE) is 300 m (550 m) where the rotational velocity exceeds the transitional velocity. The present study suggests that the anticyclonic eddies are not only likely to form larger amounts of NPSTMW, but also trap more NPSTMW than cyclonic eddies. 相似文献
12.
In order to elucidate the state of diseases, especially viral diseases, and to prevent viral diseases from occurring in olive flounder hatcheries, a range of studies, including epidemiological study, were performed from 1997 to 2003. The location of the hatcheries investigated includes several representative sites in the east （Kangnung, Uljin, Pohang, Yangsan, Ulsan, Pusan）, south （Wando, Changheung, Goheung, Yeosu, Namhae, Tongyeong, Geoje, Jeju） and west （Seosan, Kunsan, Gochang, Yeongkwang, Mokpo, Chindo） costal areas of the Korea Peninsula. A total of 2000 cases have been examined in 7 years, in which mortality caused by viral agents accounts for 22%, or 446 cases. Mortalities associated with viral infection considerably increased from 14% in 1997 to 27% in 2003. A variety of viral diseases were observed, and the occurrences of viral epidermal hyperplasia, viral ascites and viral deformity, viral nervous necrosis, and hirame rhabdoviral disease are 14%, 51%, 25%, and 8% respectively. By investigating the viral infection of broodstock flounder, the infection rate of marine birnavirus （MABV） in hatcheries was identified to be approximately 30%, therefore, it is highly necessary to acquire and keep non-infected broodstock fishes. 相似文献
13.
Geochemistry and genesis on saturated hydrocarbon of crude oils in Gas Hure Oilfield in Qaidam Basin
Gas Hure Oilfield is the biggest one in the Qaidam Basin.Through intensive sampling and GC-MS analysis,the authors analyzed the geochemical characteristics of the crude oils in the Gas Hure Oilfield.The results show that the crude oils have even-odd carbon predominance for n-alkanes.In shallow reservoir,part of crude oils suffered biogenic degradation.As for normal oils,they have low Pr/Ph ratios with abundant gammacerane and C35 homohopane,which indicate that the crude oils are formed in strong reducing sa... 相似文献
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LIAN Yi WANG Jie TU Gang REN Hongling SHEN Baizhu ZHI Keguang LI Shangfeng GAO Zongting 《中国地理科学(英文版)》2010,20(1)
Interdecadal and interannual variations of saline-alkali land area in Qian′an County, Jilin Province, China were comprehensively analyzed in this paper by means of satellite remote sensing interpretation, field flux observations and regional climate diagnosis.The results show that on the interannual scale, the impact of climate factors accounts for 71.6% of the total variation of the saline-alkali land area, and that of human activities accounts for 28.4%.Therefore the impact of climate factors is obviously... 相似文献
16.
Geochemistry and genesis on saturated hydrocarbon of crude oils in Gas Hure Oilfield in Qaidam Basin 
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下载免费PDF全文 MO Xiaoye 《世界地质(英文版)》2011,14(1):7-14
Gas Hure Oilfield is the biggest one in the Qaidam Basin.Through intensive sampling and GC-MS analysis,the authors analyzed the geochemical characteristics of the crude oils in the Gas Hure Oilfield.The results show that the crude oils have even-odd carbon predominance for n-alkanes.In shallow reservoir,part of crude oils suffered biogenic degradation.As for normal oils,they have low Pr/Ph ratios with abundant gammacerane and C35 homohopane,which indicate that the crude oils are formed in strong reducing salt water environment.Compared deep(E13) reservoir with shallow(N1-N12) reservoir,the ancient salinity of sedimentary environment of N1--N12 crude oils is slightly higher than that of E13 crude oils;the C-21/C+22 ratios of crude oils are 1.02-1.71 with a higher abundance of C27 sterane,which shows that their mainly origin matrix are bacteria and algae;the C29 sterane 20S/(20S+20R)is generally low,the ratio in deep E13 reservoir distributes between 0.31 and 0.40,but in shallow reservoir is relatively low with 0.29-0.36.At the same time,C29 sterane αββ/(αββ+ααα)and Ts/Tm both are extremely lower.All the above show that the crude oils in Gas Hure are mainly low mature oils,although the maturity of deep reservoir crude oils is slightly higher than shallow one. 相似文献
17.
Volatile organic compounds in marine algae have been reported to comprise characteristic flavor of algae and play an important role in their growth, development and defensive response. Yet their biogeneration remain largely unknown. Here we studied the composition of volatile compouds in Pyropia yezoensis and their variations in response to methyl jasmonate(MeJA) and diethyldithiocarbamic acid(DIECA) treatment using gas chromatography-mass spectrometry(GC-MS). A total of 44 compounds belonging to the following chemical classes(n) were identified, including aldehydes(11), alcohols(8), acids and esters(6), alkanes(5), ketones(5), alkenes(3), and S-or N-containing miscellaneous compounds(6). External treatment with plant hormone MeJA increased the content of 1-dodecanol, 4-heptenal, and 2-propenoic acid-2-methyl dodecylester, but decreased the content of phytol, 3-heptadecene, 2-pentadecanone, and isophytol. When pretreated with DIECA, an inhibitor of the octadecanoid pathway leading to the biosynthesis of endogeneous jasmonates and some secondary metabolites, phytol and isophytol were increased, while 4-heptenal, 1-dodecanol, and 2-propenoic acid-2-methyl dodecylester were decreased, both of which were negatively correlated with their variations under MeJA treatment. Collectively, these results suggest that MeJA does affect the volatile composition of P. yezoensis, and the octadecanoid pathway together with endogenous jasmonate pathway may be involved in the biosynthesis of volatile compounds, thereby providing some preliminary envision on the composition and biogeneration of volatile compounds in P. yezoensis. 相似文献
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《中国海洋大学学报(英文版)》2016,(3)
Codfish is a kind of abyssal fish species with a great value in food industry. However, the flavor of codfish, especially the unpleasant odor, has caused serious problems in its processing. To accurately identify the volatile compounds in codfish, a combination of solid phase micro-extraction(SPME) method and simultaneous distillation extraction(SDE) method was used to extract the volatiles. Gas chromatography-mass spectrometry(GC-MS) along with Kovats indices(KI) and authentic standard compounds were used to identify the volatiles. The results showed that a total of 86 volatile compounds were identified in codfish, of them 24 were extracted by SDE, 69 compounds by SPME, and 10 compounds by both SDE and SPME. Seventy volatile compounds were found to have specific odors, of them 7 typical compounds contributed significantly to the flavor of codfish. Alcohols(i.e.,(E)-2-penten-1-ol and 2-octanol), esters(i.e., ethyl butyrate and methyl geranate), aldehydes(i.e., 2-dodecenal and pentadecanal) contributed the most to fresh flavor while nitrogen compounds, sulphur compounds, furans, as well as some ketones(i.e., 2-hydroxy-3-pentanone) brought unpleasant odor, such as fishy and earthy odor. It was indicated that the combination of multiple extraction methods and GC-MS analysis can enhance the accuracy of identification, and provide a reference for the further study on flavor of aquatic products. 相似文献
19.
ZHANG Guosheng XU Qing GONG Zheng CHENG Yongcun WANG Lei and JI Qiyan 《中国海洋大学学报(英文版)》2014,13(2):191-197
To investigate the annual and interannual variability of ocean surface wind over the South China Sea (SCS), the vector empirical orthogonal function (VEOF) method and the Hilbert-Huang transform (HHT) method were employed to analyze a set of combined satellite scatterometer wind data during the period from December 1992 to October 2009. The merged wind data were generated from European Remote Sensing Satellite (ERS)-1/2 Scatterometer, NASA Scatterometer (NSCAT) and NASA’s Quick Scatterometer (QuikSCAT) wind products. The first VEOF mode corresponds to a winter-summer mode which accounts for 87.3% of the total variance and represents the East Asian monsoon features. The second mode of VEOF corresponds to a spring-autumn oscillation which accounts for 8.3% of the total variance. To analyze the interannual variability, the annual signal was removed from the wind data set and the VEOFs of the residuals were calculated. The temporal mode of the first interannual VEOF is correlated with the Southern Oscillation Index (SOI) with a four-month lag. The second temporal interannual VEOF mode is correlated with the SOI with no time lag. The time series of the two interannual VEOFs were decomposed using the HHT method and the results also show a correlation between the interannual variability and El Niño-Southern Oscillation (ENSO) events. 相似文献
20.
Shrimp paste is a type of condiments with high nutritional value. However, the flavors of shrimp paste, particularly the non-uniformity flavors, have limited its application in food processing. In order to identify the characteristic flavor compounds in Chinese traditional shrimp pastes, five kinds of typical commercial products were evaluated in this study. The differences in the volatile composition of the five products were investigated. Solid phase micro-extraction method was employed to extract the volatile compounds. GC-MS and electronic nose were applied to identify the compounds, and the data were analyzed using principal component analysis (PCA). A total of 62 volatile compounds were identified, including 8 alcohols, 7 aldehydes, 3 ketones, 7 ethers, 7 acids, 3 esters, 6 hydrocarbons, 12 pyrazines, 2 phenols, and 7 other compounds. The typical volatile compounds contributing to the flavor of shrimp paste were found as follows: dimethyl disulfide, dimethyl tetrasulfide, dimethyl trisulfide, 2, 3, 5-trimethyl-6-ethyl pyrazine, ethyl-2, 5-dimethyl-pyrazine, phenol and indole. Propanoic acid, butanoic acid, furans, and 2-hydroxy-3-pentanone caused unpleasant odors, such as pungent and rancid odors. Principal component analysis showed that the content of volatile compounds varied depending on the processing conditions and shrimp species. These results indicated that the combinations of multiple analysis and identification methods could make up the limitations of a single method, enhance the accuracy of identification, and provide useful information for sensory research and product development. 相似文献