222 resultados para LC-APCI-MS
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To gain an insight into the function of shrimp lymphoid organ at protein level, we analyzed the proteome of lymphoid organ in healthy Chinese shrimp Fenneropenaeus chinensis (F. chinensis) through two-dimensional gel electrophoresis (2-DE) based proteomic approach. A total of 95 spots representing 75 protein entries were identified by liquid chromatography tandem mass spectrometry (LC-MS/MS) with both online and in-house database. According to Gene Ontology (GO) annotation of biological process, the identified proteins were classified into 13 categories. Among them, approximately 36% of proteins related to cytoskeleton are noticeable. Then, a comparative proteomic approach was employed to investigate the differentially expressed proteins in lymphoid organ of Vibrio anguillarum-challenged F. chinensis. At 24 h post-injection (hpi), 17 differentially expressed protein spots were successfully identified, including 4 up-regulated protein spots (represent 4 proteins: cathepsin L protein similar to squid CG16901-PC, protein kinase C and protein similar to T-complex Chaperonin 5 CG8439-PA), and 13 down-regulated protein spots (represent 9 proteins: actin, beta-actin, cytoplasmic actin CyII, alpha tubulin, beta tubulin, protein similar to proteasome delta, vacuolar ATP synthase subunit B, elongation factor 2, carboxypeptidase B). These data may help us to understand the function of lymphoid organ and the molecular immune mechanism of shrimp responsive to pathogen infection. (C) 2010 Elsevier Ltd. All rights reserved.
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An off-line chelation system combined with ICP-MS technique was developed for the quantitative determination of trace elements in seawater, namely V, Co, Ni, Cu, Zn, Mo, Cd, Pb, U and rare earth elements(REEs). The system was built based on an ion chromatography equipped with MetPac((R)) CC-I chelation columns which had a strong selective chelation to these target elements within a pH range 5.2-5.6. Acidified seawater samples and NH4Ac(2 mol/L) were blended to meet suitable pH before being injected into the chelation column, thus target elements were retained while alkali and alkaline metals were excluded. Then chelated elements were eluted by HNO3 (1 mol/L) and samples were collected for ICP-MS analysis. Varying the ratio of input( gen. 200 mL) to output( gen. 5 mL), the target elements which were concentrated as 40 times as their concentrations were far beyond instrumental quantification limits. At last, a certificated seawater CASS-4 was introduced and our detected values were in good agreement with those certified values.
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近几十年来,国内沿海地区频繁发生食用织纹螺中毒事件,并导致数十人死亡,这一问题得到了政府相关部门的高度重视。但是,由于织纹螺毒性变化很大,毒素来源不清楚,因此很难预测食用织纹螺中毒事件的发生,这在很大程度上限制了对食用织纹螺中毒事件的有效监测和管理。目前,对于中国沿海有毒织纹螺体内河豚毒素(tetrodotoxin, TTX)的来源还未见过系统研究。本文选取中国沿海常见的半褶织纹螺(Nassarius semiplicatus)、纵肋织纹螺(N. variciferus)和拟半褶织纹螺(N. semiplicatoides sp. nov.)作为实验对象,从毒素的微生物来源与食物链来源这两个角度分别展开研究,以探讨织纹螺体内 TTX 的可能来源,为提出相应的预防管理措施提供科学依据。 首先,我们先后从曾发生过中毒事件的江苏盐城和连云港采集了织纹螺样品,通过小鼠生物测试法和液-质联用分析技术(LC-MS),对织纹螺的毒性和毒素组成进行了测试和分析,分离培养了织纹螺体内及其生活环境中的细菌,应用河豚毒素单克隆抗体酶联免疫检测方法(ELISA)对细菌的产毒情况进行了测试,并通过 16S 核糖体(rRNA)部分基因序列测定对细菌种类进行了初步的分析。研究发现,采自江苏盐城和连云港的半褶织纹螺的毒性分别约为 2 MU/g 和 200 MU/g 组织,体内的毒素成分是河豚毒素及其同系物。从盐城的半褶织纹螺及其生活环境分离的菌株中随机挑出 14 个菌株中,9 个菌株河豚毒素检测结果呈现阳性。从连云港高毒性半褶织纹螺消化腺中分离到的 45 个菌株中,阳性菌株有 21 个。但是,有毒菌株毒素含量较低,毒素含量范围是 15-184ng/g。通过 16S rDNA 部分序列的测序结果发现,大部分有毒菌株与弧菌属(Vibrio)的细菌在遗传序列信息上比较相近。其余有毒菌株分别与希瓦氏菌属(Shewanella)、海单胞菌属(Marinomonas)、黄杆菌属(Tenacibaculum)、动性菌属(Planococcus)、发光杆菌属 (Photobacterium)和气单胞菌属(Aeromonas)的遗传序列比较相近。其中与海单胞菌属、动性菌属和发光杆菌属亲缘关系较近的产毒细菌是首次报道。这一研究表明织纹螺体内及其生活环境中的存在产河豚毒素的细菌,但由于产毒素的量较低,因此可能在织纹螺体内河豚毒素的产生和累积过程并不发挥主要作用。 织纹螺作为一类腐食性的海洋动物,也有可能通过进食含有河豚毒素的生物而累积河豚毒素。对此,我们开展了高毒性半褶织纹螺的室内培养实验,以及河豚毒素在不同种类织纹螺体内的累积和排出的模拟实验,并定期采样,通过液相色谱与串联质谱联用技术(LC-MS/MS)对织纹螺体内河豚毒素及其同系物的含量变化情况进行了分析。室内培养实验发现,从连云港赣榆县采集的高毒性半褶织纹螺,在实验初期,体内毒素含量呈下降的趋势,但从 7月上旬开始,毒素含量突然快速上升,与连云港赣榆县野外采集的织纹螺的毒素含量表现出相似的变化趋势。河豚毒素在不同种织纹螺体内的累积和排出的模拟实验发现,通过投喂高毒性的河豚鱼肝脏(毒性为5×103 MU/g),纵肋织纹螺在一段时间内能够快速累积少量的河豚毒素。当停止投喂有毒河豚鱼肝脏后,毒素含量会快速下降。而在曾导致中毒事件的拟半褶织纹螺中,投喂有毒河豚鱼的肝脏后,其体内毒素含量只有缓慢增加。但在投喂无毒的河豚鱼肝脏后,其毒性却出现了快速增加的现象,这与该地区野外样品的毒性变动状况类似。这些发现显示高毒性半褶、拟半褶织纹螺体内的河豚毒素应当不是食物链累积的结果,而可能是由其自身产生。并且,毒素含量的变化具有一定的生物节律,有可能与产卵、繁殖等自然节律相关。 通过对半褶、纵肋和拟半褶织纹螺的研究工作可以认为,产河豚毒素的细菌不是织纹螺体内河豚毒素的主要来源,并且毒素也不是来自其摄食的食物,推测可能主要是由织纹螺自身产生。织纹螺所表现出的河豚毒素含量的季节性变化,极有可能与产卵、繁殖等自然节律相关,这些发现为预防和管理食用织纹螺中毒事件提供了科学依据。但是,本研究并未完全阐明织纹螺体内河豚毒素的来源,对于织纹螺体内河豚毒素的确切来源以及河豚毒素的代谢和转化机制,还有待于更加深入地研究工作。
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近年来,分子生物学技术与方法被越来越多地应用于有害赤潮研究。其中,单细胞PCR方法是对难以室内培养的有害赤潮藻种进行遗传特征研究的一项重要技术。本实验尝试建立微藻的单细胞PCR方法,并将其应用于鳍藻研究。 应用室内培养的亚历山大藻,研究了微藻的单细胞PCR方法,并对藻细胞的固定和保存方法进行了比较。结果表明,浮游植物研究中常用的甲醛固定方法只能用于短期保存样品(少于5天),而乙醇固定、鲁格氏液固定、或者在-20℃下冷冻保存的样品,在较长的时间后(60天)仍可以得到比较理想的PCR扩增结果。 应用单细胞PCR方法,对青岛近海采集的鳍藻进行了研究,扩增并测定了包括核糖体大亚基(LSU)rDNA的5’端D1-D2区序列,以及5.8S rDNA和ITS区的部分序列信息。通过分析软件对所得到的鳍藻序列信息与基因库中已知的鳍藻序列信息进行了分析与对比。根据ITS和LSU序列信息构建的系统进化树都显示,本文采集的鳍藻藻种与国外报道的圆形鳍藻聚为一支,初步确定采集的鳍藻应为圆形鳍藻,对该藻种形态学特征的观察也支持这一结果。该藻种部分LSU rDNA序列与欧洲同种鳍藻相似度达到99%,与其它等鳍藻遗传距离在18%-20%之间。测定的ITS区序列与同种圆形鳍藻有62个碱基的差异,与LSU rDNA序列相比,ITS序列变异更大。应用LC-MS方法对该鳍藻的进行了DSP毒素分析,结果未检测到OA或DTX1毒素。 这是我国首次应用单细胞PCR方法对鳍藻开展的研究工作,首次报道了我国鳍藻的核糖体部分序列信息。圆形鳍藻在青岛近海海域是初次报道,显示了单细胞PCR方法在鳍藻研究中的重要意义。
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织纹螺(Nassarius spp.)味道鲜美,是中国及其它一些亚洲国家沿海地区居民习惯食用的一种水产品。但是,近几十年来,中国沿海频繁发生食用织纹螺中毒事件,严重威胁着人们的身体健康和生命安全。加之人们对织纹螺体内的毒素成分、来源及其毒性变化规律还没有清晰的认识,因此难以有效预防和控制食用织纹螺引起的中毒事件。本文根据文献报道,在中国沿海食用织纹螺中毒事件多发的典型区域,包括江苏省的连云港市和盐城市、浙江省的舟山市和宁波市、福建省的宁德市、厦门市和莆田市设立了监测点,于2006年和2007年间进行了连续采样,应用小鼠生物测试法调查了织纹螺毒性的消长情况,并利用高效液相色谱-质谱联用(Liquid Chromatography-Mass Spectrometry,LC-MS)和高效液相色谱技术(High Performance Liquid Chromatography,HPLC)对织纹螺体内的毒素成分进行了分析。 实验结果表明,2006年于江苏省盐城市射阳海域采集的织纹螺样品中,阳性样品检出率为56%,毒性在2-5 MU/g组织(湿重)之间变化,在2007年于同地采集的8个样品中,除一个样品毒性为3.14 MU/g组织(湿重)以外,其余样品均表现为阴性;而2007年采集自连云港市赣榆海域的织纹螺样品,在采样期间则呈现出极高的毒性,最高达到846.52 MU/g 组织(湿重),毒性在监测期间呈“M”状波动,在5月和7月下旬出现两个毒性高峰。2006年于浙江省宁波市象山港采集的织纹螺样品中,阳性样品检出率为25%,毒性均在2.5 MU/g组织(湿重)左右;而同年采集自舟山市定海的织纹螺样品中,阳性样品检出率为100%,最高毒性达18.40 MU/g组织(湿重),毒性在监测期间也呈“M”状波动,高峰期出现在6月初和7月底。2006年3-9月采集自福建省宁德霞浦、厦门同安和莆田涵江采集的织纹螺样品中,阳性样品检出率分别为20%、43%和14%,除7月中旬采集自宁德霞浦的一个样品毒性达到16.19 MU/g组织(湿重)之外,其余样品毒性均在2-5 MU/g组织(湿重)间波动。从阳性样品的时间分布规律来看,3月份和6、7月份是阳性样品集中出现的时期。根据以上调查结果可以看出,织纹螺的毒性消长呈现出较明显的地域性和季节性特征,不同地区的织纹螺毒性存在差异,而同一区域织纹螺毒性的消长则表现出明显的季节性集中趋势。除了2007年采集自连云港赣榆的织纹螺样品毒性与其平均个体组织重量有相似的变化趋势以外,其余地区的织纹螺样品毒性和个体大小无明显相关性。 利用LC-MS和HPLC技术对织纹螺样品中的毒素成分进行了分析,确定河豚毒素(tetrodotoxin, TTX)及其同系物(trideoxyTTX,4-epi-TTX,anhydroTTX,oxoTTX)是所采集织纹螺中的主要致毒成分,样品中没有检测到麻痹性贝毒毒素(Paralytic Shellfish Poison, PSP)。自不同地区采集的织纹螺中毒素成分基本一致,但组成存在一定差异。其中,采自江苏省连云港赣榆和浙江省舟山定海的织纹螺样品中,trideoxyTTX是主要的成分,其次是TTX;而从其它采样地点采集的织纹螺中,TTX都是主要的毒素成分,其次才是trideoxyTTX及其它同系物。对采集自江苏省连云港赣榆和浙江舟山定海的织纹螺体内毒素的解剖学分布进行了分析,结果表明肌肉、消化腺和剩余部分中的毒素组成基本一致,其中trideoxyTTX是主要的毒素成分,其次为TTX,但采自浙江舟山的织纹螺剩余部分中的TTX是主要的毒素成分。在监测期间,各组织中的毒素组成没有明显变化,但毒素含量随季节变化表现出了一定的差异。 综上所述,在中国沿海典型区域开展的织纹螺毒性调查结果表明其毒性消长具有一定的地域性和季节性特征。分析结果显示织纹螺体内的毒素成分是河豚毒素及其同系物,采自不同区域的织纹螺体内毒素成分基本一致,但毒素组成稍有差异。对织纹螺中毒素的解剖学分布研究显示,各组织中的毒素含量随季节变化而表现出一定差异,但毒素组成没有明显的季节性变化。这些结果显示中国沿海的织纹螺应具有相似的毒素来源,研究结果将为相关部门有效监测、预防和控制食用织纹螺中毒事件提供有力的科学依据。
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Bacteria isolated from a highly toxic sample of gastropod Nassarius semiplicatus in Lianyungang, Jiangsu Province in July 2007, were studied to probe into the relationship between bacteria and toxicity of nassariid gastropod. The toxicity of the gastropod sample was 2 x 10(2) mouse unit (MU) Per gram Of tissue (wet weight). High concentration of tetrodotoxin (TTX) and its analogues (TTXs) were found in the digestive gland and muscle of the gastropod, using high performance liquid chromatography coupled with mass chromatography (LC-MS). Bacterial strains isolated from the digestive gland were cultured and screened for TTX with a competitive ELISA method. Tetrodotoxin was detected in a proportion of bacterial strains, but the toxin content was low. Partial 16S ribosomal DNA (rDNA) of the TTX-producing strains was then sequenced and compared with those published in the GenBank to tentatively identify the toxic strains. It was found that most of the toxic strains were closely affiliated with genus Vibrio, and the others were related to genus Shewanella, Marinomonas, Tenacibaculum and Aeromonas. These findings suggest that tetrodotoxin-producing bacteria might play an important role in tetrodotoxin accumulation/production in N. semiplicatus. (C) 2008 Elsevier Ltd. All rights reserved.
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[目的]基于气相色谱-质谱(GC-MS)法测定藏木香栽培品种挥发油的化学成分。[方法]采用水蒸气蒸馏法从藏木香栽培品种中提取挥发油,并用GC-MS联用仪对其挥发油的化学成分进行研究。[结果]分离并确认了37种成分,其主要成分是桉叶油二烯5,11(13)-内酯-8,12,异-榄香烯,异-喇叭烯,桉叶油二烯4,11(13)-内酯-8,12。[结论]分析获得的主要化学成分及其功效为藏木香这一天然药用植物资源的人工规范化栽培和进一步综合开发利用提供了科学依据。
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目的:分析治疗胃病常用的藏成药帕朱胶囊(寒水石,诃子,石榴子,胡椒,荜拔等)的主要化学成分。方法:采用超临界CO_2萃取方法提取帕朱胶囊的可溶性成分,并用气相色谱-质谱联用法对提取部位进行化学成分分析,峰面积归一化法计算各组分的相对含量。结果:共分离鉴定了22种化合物,主要成分含量为胡椒碱44.2%、亚油酸21.1%、甲基-甲撑基奥-异丙烯内酯10.5%、棕榈酸4.8%和γ-羟基-榄香烯酸内酯3.5%等。结论:藏药帕朱胶囊的主要化学成分为胡椒碱和亚油酸,两者含量共占全部提取物的65.3%
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目的:用新方法提取藏药材石榴籽油,并对其进行化学成分分析,为石榴籽的药理研究和应用提供实验依据。方法:采用超临界CO_2萃取方法提取石榴籽的可溶性成分,并用气相色谱-质谱联用法对提取部位进行化学成分分析,峰面积归一化法计算各组分的相对含量。结果:共分离鉴定了10种化合物,主要成分含量为亚油酸40.0%、油酸22.7%、棕榈酸17.5%、硬脂酸9.0%及共轭亚油酸5.7%。结论:藏药材石榴籽的主要化学成分为亚油酸和油酸,两者含量共占全部提取物的62.7%。
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蕨麻,藏医谓之卓老沙曾,原植物为蔷薇科委陵菜属鹅绒委陵菜Potentilla anserine L.,为多年生草本.在高海拔地区蕨麻根的中下部形成块根,在温暖低平地区不形成膨大的块根[1].蕨麻全草入药,收敛止血,止咳利痰,治各种出血及下痢.块根入药,有健脾益胃、生津止渴、益气补血功效;治脾虚、腹泻、产后贫血、营养不良等症[2].
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目的 分析全缘叶绿绒蒿、五脉绿绒蒿和多刺绿绒蒿挥发油的化学成分.方法 采用水蒸气蒸馏法获得挥发油,经GC-MS技术结合计算机检索对其化学成分进行分离和鉴定,用色谱峰面积归一化法计算各组峰的相对含量.结果 从全缘叶绿绒蒿、五脉绿绒蒿和多刺绿绒蒿的挥发油中分别鉴定了25,42和53个化合物,占其各自总量的80.76%,73.34%和76.10%.结论 3种绿绒蒿挥发油化学成分存在一定程度的差异,但其主要成分都为酯类物质
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利用超临界CO_2萃取唐古特白刺籽油,并对籽油进行了GC/MS分析。实验确定的最佳超临界CO_2流体萃取条件是:萃取温度45℃,萃取压力20 MPa,CO_2流量为35-40 kg/h,萃取时间120min,在此条件下白刺籽油的萃取率为15.11%。利用GC/MS对白刺籽油分析,发现其不饱和脂肪酸的相对含量高达93.37%。比较了超临界CO_2萃取白刺籽油油样和石油醚萃取白刺籽油油样的理化性质,发现超临界CO_2流体萃取的籽油质量优于传统溶剂萃取的籽油。
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A highly selective and accurate method based on derivatization with dansyl chloride coupled with liquid chromatography-mass spectrometry has been developed for identification of natural pharmacologically active phenolic compounds in extracts of Lomatogonium rotatum plants (Tibetan herbal medicine) obtained by solid-phase extraction. The number of hydroxyl groups on the dansylated phenols was estimated by LC-MS-MS analysis in positive-ion mode. Dansyl derivatization of the compounds introduced basic secondary nitrogen into the phenolic core structures and this was readily ionized when acidic HPLC mobile phases were used. MS fragmentation of the derivatives generated intense protonated molecular ions of m/z [MH](+) (phenol aglycones were transformed into the corresponding free phenols by cleavage of an aglycone bond). Collision-induced dissociation of the protonated molecule generated characteristic product ions of m/z 234 and 171 corresponding to the protonated 5-(dimethylamino)naphthalene sulfoxide and 5 -(dimethylamino) naphthalene moieties, respectively. Selected reaction monitoring based on the m/z [MH](+) to 234 and 171 transitions was highly specific for these phenolic compounds. Characteristic ions with m/z values of [MH - 234](+), [MH 2 x 234](+), and [MH - 3 x 234](+) were of great importance for estimation of the presence of multihydroxyl groups on the phenolic backbone.
Resumo:
Based on previous studies, boron can be separated from aqueous samples with Amberlite IRA-743 resin. Experiments on the elute temperature, elute volume and the dynamic resin exchange capacity have been performed in this study. Results show that the dynamic exchange capacity of the resin is 4.2mg B/g and at room temperature, boron fixed on the resin within this capacity level can be extracted quantitatively by using 5ml 2%HNO3. A new procedure has been developed for the measurement of boron isotope ratios in water samples using a Neptune MC-ICP-MS, after resolving the memory effect, which is a key problem, and investigating the impacts of mass bias and Si matrix effect. Using this method, it usually takes 20 min to perform one measurement on 0.1ppm boron solution with a precision of 0.23‰ (SD). If the relative deviation between a sample and the standard is large, the washout time needs to be doubled to achieve a higher precision. δ11B values of water samples from Yangbajing geothermal field vary from -10.53 to -9.13‰. Owing to the large difference B concentration and the small B isotope difference between deep geothermal water and surface water, B isotope ratios of the shallow geothermal fluids are dominated by the deep end member rather than the shallower one in the mixing process. As a consequence, δ11B-B relation is indicative basically of a dilution process. Vapor-liquid separation and calcite scaling also greatly influence B isotope fractionation. δ11B values of water samples from Dagejia geothermal field are from -15.98‰ to -11.67‰. Boron in Changma River near the field has two sources, freshwater lakes (Dajiamang Lake and Canke Lake) and geothermal waters. Finally, a preliminary discussion is included on boron geochemical characteristics of the salt lakes in Shuanghu area and other geothermal fields, to provide information for future studies on boron isotope geochemistry of geothermal systems and salt lakes in Tibet.
Resumo:
Over past ten years, a great development has been made in the Lu-Hf isotopic system with the advent of MC-ICP-MS. Based on a comprehensive review of available references in the related field, a novel analytical protocol of three exchange chromatographies after one mixed acid attacking geological samples was developed in this work, which not only avoids common multiple sample treatments for natural inhomegeneous samples, but also is useful for Rb-Sr, Sm-Nd and Lu-Hf isotopic system simultaneously, especially for the garnet- and apatite-bearing rocks for the Sm-Nd and Lu-Hf geochronology. An analytical procedure for the Lu and Hf concentration in geological samples determined by by ID-MC-ICP-MS was detailedly investigated. The Hf yield is > 90 % and total procedural blank is less than. 50 pg for Hf and 10 pg for Lu, respectively. The developed method was successfully applied to the determination of Lu and Hf concentrations for USGS geological materials. A one-column procedure for Hf purification in geological samples using common anion exchange chromatography and its isotopic analyses by MC-ICP-MS were also established. Multiple analyses of Standard Reference Materials demonstrate that this method was simple, time-saving, cheap and efficient, especially suitable for the Hf isotopic compositions of young samples. Finally, the measurements of Sr and Nd isotopic compositions using Neptune MC-ICP-MS were described briefly, which indicates that Neptune MC-ICP-MS can precisely measure Sr and Nd isotopic compositions as the TIMS does, even more efficient and less time-consuming than the TIMS method. The Hf isotopic characteristics of typical volcanic rocks (Cenozoic Changle-Linqu basalts, Mesozoic Fangcheng basalts, Mesozoic Jianguo basalts, Mesozoic Wulahada high-Mg andesite, Cenozoic Fanshi, Zuoquan and Xiyang-Pingding basalts of the Taihang Mountains, Paleozoic diamondiferous Menyin and Fuxian Kimblites) from the North China Craton were firstly studied in this work. Coupled with Nd isotopic compositions, it shows that the Hf isotopes could be a better tracer for mantle sources than the Nd isotopes. Individual kimberlite fields from both the Mengyin and Fuxian regions have quite uniform Hf isotopic compositions, similar to the situation for the Nd isotopes.