101 resultados para APCI


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The feasibility of different modern analytical techniques for the mass spectrometric detection of anabolic androgenic steroids (AAS) in human urine was examined in order to enhance the prevalent analytics and to find reasonable strategies for effective sports drug testing. A comparative study of the sensitivity and specificity between gas chromatography (GC) combined with low (LRMS) and high resolution mass spectrometry (HRMS) in screening of AAS was carried out with four metabolites of methandienone. Measurements were done in selected ion monitoring mode with HRMS using a mass resolution of 5000. With HRMS the detection limits were considerably lower than with LRMS, enabling detection of steroids at low 0.2-0.5 ng/ml levels. However, also with HRMS, the biological background hampered the detection of some steroids. The applicability of liquid-phase microextraction (LPME) was studied with metabolites of fluoxymesterone, 4-chlorodehydromethyltestosterone, stanozolol and danazol. Factors affecting the extraction process were studied and a novel LPME method with in-fiber silylation was developed and validated for GC/MS analysis of the danazol metabolite. The method allowed precise, selective and sensitive analysis of the metabolite and enabled simultaneous filtration, extraction, enrichment and derivatization of the analyte from urine without any other steps in sample preparation. Liquid chromatographic/tandem mass spectrometric (LC/MS/MS) methods utilizing electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) were developed and applied for detection of oxandrolone and metabolites of stanozolol and 4-chlorodehydromethyltestosterone in urine. All methods exhibited high sensitivity and specificity. ESI showed, however, the best applicability, and a LC/ESI-MS/MS method for routine screening of nine 17-alkyl-substituted AAS was thus developed enabling fast and precise measurement of all analytes with detection limits below 2 ng/ml. The potential of chemometrics to resolve complex GC/MS data was demonstrated with samples prepared for AAS screening. Acquired full scan spectral data (m/z 40-700) were processed by the OSCAR algorithm (Optimization by Stepwise Constraints of Alternating Regression). The deconvolution process was able to dig out from a GC/MS run more than the double number of components as compared with the number of visible chromatographic peaks. Severely overlapping components, as well as components hidden in the chromatographic background could be isolated successfully. All studied techniques proved to be useful analytical tools to improve detection of AAS in urine. Superiority of different procedures is, however, compound-dependent and different techniques complement each other.

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Cattle grazing in arid rangelands of Australia suffer periodic extensive and serious poisoning by the plant species Pimelea trichostachya, P. simplex, and P. elongata. Pimelea poisoning (also known as St. George disease and Marree disease) has been attributed to the presence of the diterpenoid orthoester simplexin in these species. However, literature relating to previous studies is complicated by taxonomic revisions, and the presence of simplexin has not previously been verified in all currently recognized taxa capable of inducing pimelea poisoning syndrome, with no previous chemical studies of P. trichostachya (as currently classified) or P. simplex subsp. continua. We report here the isolation of simplexin from P. trichostachya and the development of a liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) method to measure simplexin concentrations in pimelea plant material. Simplexin was quantified by positive-ion atmospheric pressure chemical ionization (APCI) LC-MS/MS with selected reaction monitoring (SRM) of the m/z 533.3 > 253.3 transition. LC-MS/MS analysis of the four poisonous taxa P. trichostachya, P. elongata, P. simplex subsp. continua, and P. simplex subsp. simplex showed similar profiles with simplexin as the major diterpenoid ester component in all four taxa accompanied by varying amounts of related orthoesters. Similar analyses of P. decora, P. haematostachya, and P. microcephala also demonstrated the presence of simplexin in these species but at far lower concentrations, consistent with the limited reports of stock poisoning associated with these species. The less common, shrubby species P. penicillaris contained simplexin at up to 55 mg/kg dry weight and would be expected to cause poisoning if animals consumed sufficient plant material.

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Miniaturized mass spectrometric ionization techniques for environmental analysis and bioanalysis Novel miniaturized mass spectrometric ionization techniques based on atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI) were studied and evaluated in the analysis of environmental samples and biosamples. The three analytical systems investigated here were gas chromatography-microchip atmospheric pressure chemical ionization-mass spectrometry (GC-µAPCI-MS) and gas chromatography-microchip atmospheric pressure photoionization-mass spectrometry (GC-µAPPI-MS), where sample pretreatment and chromatographic separation precede ionization, and desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS), where the samples are analyzed either as such or after minimal pretreatment. The gas chromatography-microchip atmospheric pressure ionization-mass spectrometry (GC-µAPI-MS) instrumentations were used in the analysis of polychlorinated biphenyls (PCBs) in negative ion mode and 2-quinolinone-derived selective androgen receptor modulators (SARMs) in positive ion mode. The analytical characteristics (i.e., limits of detection, linear ranges, and repeatabilities) of the methods were evaluated with PCB standards and SARMs in urine. All methods showed good analytical characteristics and potential for quantitative environmental analysis or bioanalysis. Desorption and ionization mechanisms in DAPPI were studied. Desorption was found to be a thermal process, with the efficiency strongly depending on thermal conductivity of the sampling surface. Probably the size and polarity of the analyte also play a role. In positive ion mode, the ionization is dependent on the ionization energy and proton affinity of the analyte and the spray solvent, while in negative ion mode the ionization mechanism is determined by the electron affinity and gas-phase acidity of the analyte and the spray solvent. DAPPI-MS was tested in the fast screening analysis of environmental, food, and forensic samples, and the results demonstrated the feasibility of DAPPI-MS for rapid screening analysis of authentic samples.

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This study is focused on the development and evaluation of ion mobility instrumentation with various atmospheric pressure ionization techniques and includes the following work. First, a high-resolution drift tube ion mobility spectrometer (IMS), coupled with a commercial triple quadrupole mass spectrometer (MS), was developed. This drift tube IMS is compatible with the front-end of commercial Sciex mass spectrometers (e.g., Sciex API-300, 365, and 3000) and also allows easy (only minor modifications are needed) installation between the original atmospheric pressure ion source and the triple quadrupole mass spectrometer. Performance haracteristics (e.g.,resolving power, detection limit, transmission efficiency of ions) of this IMS-MS instrument were evaluated. Development of the IMS-MS instrument also led to a study where a proposal was made that tetraalkylammonium ions can be used as chemical standards for ESI-IMS. Second, the same drift tube design was also used to build a standalone ion mobility spectrometer equipped with a Faraday plate detector. For this highresolution (resolving power about 100 shown) IMS device, a multi-ion source platform was built, which allows the use of a range of atmospheric pressure ionization methods, such as: corona discharge chemical ionization (CD-APCI), atmospheric pressure photoionization (APPI), and radioactive atmospheric pressure chemical ionization (R-APCI). The multi-ion source platform provides easy switching between ionization methods and both positive and negative ionization modes can be used. Third, a simple desorpion/ionization on silicon (DIOS) ion source set-up for use with the developed IMS and IMS-MS instruments was built and its operation demonstrated. Fourth, a prototype of a commercial aspiration-type ion mobility spectrometer was mounted in front of a commercial triple quadrupole mass spectrometer. The set-up, which is simple, easy to install, and requires no major modifications to the MS, provides the possibility of gathering fundamental information about aspiration mobility spectrometry.

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本学位论文分为四个部分,第一部分报道了用串联质谱快速分析合成药物中的微量杂质成分以及分析中药材中的化学成分。第二部分报道了通过质谱和串联质谱发现并合成新型的PdPincer 催化剂,同时对其活性进行测试。第三部分为串联质谱自动解析软件的设计及应用。第四部分概述了应用在质谱中的各种碎裂方式。 第一部分首先总结了5-溴粉防己碱及其类似物的裂解规律,并以此为根据推测出2 个微量杂质的结构。随后针对无患子(Sapindus mukurossi Gatren.)中的皂苷成分,由ESI-QTOF 得到各个皂苷成份的高分辨质量数据进而得到其分子式,然后利用ESI-IT 电喷雾串联质谱对无患子总皂苷中各皂苷成分的结构进行进一步的鉴定。进而以同样的方式,先通过ESI-QTOF 得到黄山药(Dioscoreapanthaica)总皂苷中各个组分化合物的分子式,然后对已有的薯蓣皂苷标准品做串联质谱分析,以得到该类化合物的裂解规律并给出解析该类化合物的流程图。在此利用计算化学的方法讨论了离子的丰度与裂解活化能之间的关系。然后应用APCI-MS/MS 方法探讨了四对同分异构体和几个已知的化合物,并最后用液质联用对其进行确认,同时还给出了4 个未知化合物的可能结构。 第二部分报道通过质谱和串联质谱发现并合成新型的PdPincer 催化剂,同时对其活性进行测试。钯催化的交联反应是有机合成中C-C 键形成的最有效的方法,且硫脲是一类对空气和水都稳定的化合物,因此我们设计并合成了一系列的硫脲钯催化剂并得到了很好的催化活性。我们在对其中一类环状双硫脲化合物进行质谱实验的时候,在正离子模式下发现了反常的[M.H]+,通过串联质谱进一步确定了它是一种新型的PdPincer 结构。我们将其合成出来并通过X-ray 衍射实验确定了它的结构。同时测定其催化活性并与未形成pincer 的类似物进行比较发现该类化合物具有较宽的底物适用性。 第三部分为串联质谱自动解析软件的设计及应用。通过前面两部分的启示,独立设计开发了AuMass(1.0)。其算法是:先通过查找特殊的碎片离子,中性丢失或碎片离子质量差来确定某类化合物的骨架结构,然后利用该类化合物的自动解析流程来对其周边取代基进行确认。通过它快速地对白芍中的化学成分进行解析,并对未知的化合物进行了推测。为了增加它的解析能力,我又对其它类型的化合物裂解规律进行总结,并给出了自动解析流程。实践证明该软件具有相当好的应用价值。 第四部分综述了应用在质谱上的各类母离子的碎裂技术。这里包括了碰撞诱导裂解(CID)、光诱导碎裂(LID)、电子捕获裂解/电子转移裂解(ECD/ETD)、红外多光子解离(IRMPD)、黑体辐射解离(BIRD)和PQD 裂解技术。 This dissertation consists of four chapters. The first chapter reports the rapidanalysis of trace impurities from synthetical medicine and analysis of the chemicalconstitutents from Chinese herb medicines. The second chapter elaborates the studieson the discorvery and synthesis of new type of Pd Pincer catalyst by using MS andtandem MS together with the testing of its catalyst activity. The third chapter dwellson the designation and development of automatic tandem mass spectrometry analysissoftware. The last chapter presents a review on the dissociation technique of massspectrometry. The first chapter reports the rapid analysis of trace impurities from synthesismedicine and analysis of the chemical constitutents from Chinese herb medicines. The fission mechanism of 5-bromotetrandrine was obtained by analysis of the dissociationpathways of major product, by using which the possible structure of the two traceimpurties was assumed. There are lots of saponins in Sapindus mukurossi. Except forthe good spumescence and decontamination,it possesses the bioactivity of antigenand antitch. First of all, the high resolution mass information was obtained by ESI-QTOF. Hence the possible molecular formulars were acquired too. Then weconducted the further detection of the structures of its saponins by using ESI-ITtechnology. In the same manner, first the molecular formulars of every constituentfrom Dioscorea panthaica in total saponins were obtained by ESI-QTOF, and thenacquired the fission mechanism of this type of compounds by tandem massexperiment on a series of known and available saponins. In the same time, theanalysis flowchart was concluded. Here the relationship between the ion intensity andthe corresponding dissiociation activation energy was studied by computer chemistry.Then the four pairs of isomers were differentiated by APCI-MS/MS, as well as thecharacterization of known and unknown compounds. The assumption was confirmed by HPLC-MS/MS. Among them the possible structures of four unknown saponinswas presented. The second part was discovery and synthesis of a new type of Pd pincer catalystby MS and tandem MS. The coupling reaction catalyzed by Pd is the most effectivemethod in C-C formation in organic synthesis. Apart from that, thiourea is type ofcompounds that are stable to atmosphere and moisture. Hence we designed a series ofPd thiourea catalysts. Some of them show the excellent catalyst activity. The abnormalparent ion [M.H]+ was founded in positive ESI mode when we conduct some massspectrometry experiments on the bicyclical thiourea Pd complex. The structure wasproposed by mass and tandem mass spectrometry. Because it was a new type of pincer,we want to test its catalyst activity. So the Pd pincer was synthesized and the detailstructure was obtained by x-ray experiment. It shows the more fitness in catalysis ofSuzuki reaction by comparison with the analogue. The third chapter dwells on the design and development of automatic tandemmass spectrometry analysis software. Inspired by the former two chapters, theAuMass (version 1.0) was developed. Its algorithm is: first check the diagnostic ion,diagnostic neutral loss or diagnostic ions mass intervals in database to find out whatthe analyst’s skeleton belongs to, then identify the peripheral functional group by thecorresponding analysis flowchart. The chemical constituents of Paeonia lactiflorawere identified rapidly by using AuMass. To increase the analysis ability, the othertypes of compounds from Chinese herbs was concluded. Actually, the software isproven to have the much valuable application. The last chapter presented the review on the some kinds of fission technique ofmass spectrometry. It involves the collision induced dissociation (CID), laser induceddissociation (LID), electron capture dissociation/electron transfer dissociation(ECD/ETD), infrared multiple photons dissiociation, black body irraditiondissociation and PQD fission technique from Finnigan.

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A comprehensive two-dimensional liquid chromatographic separation system based on the combination of a CN column and an ODS column is developed for the separation of components in a traditional Chinese medicine (TCM) Rhizoma chuanxiong. Two columns are coupled by a two-position, eight-port valve equipped with two storage loops and controlled by a computer. The effluent is detected by both the diode array detector and atmospheric pressure chemical ionization (APCI) mass spectrometer. More than 52 components in the methanol extract of R. chuanxiong were resolved and 11 of them were preliminary identified according to their UV and mass spectra. (C) 2004 Elsevier B.V. All rights reserved.

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有机锡化合物被广泛用作塑料制品中的稳定剂、船舶油漆的防污剂、工业催化剂、农林业杀虫杀菌剂以及用于木材的防腐保存等,已经引起严重的环境污染。世界上许多国家纷纷制定相应的法规对其使用加以禁止或限制。我国目前还没有明确的限制有机锡使用的法律法规,缺少有机锡污染的第一手资料,更没有长期的控制、监测与研究计划。由于有机锡的种类繁多,理化性质存在差别,所以在提取、分离和测定中均存在较大的困难。从我国这方面己有的工作来看,缺乏各种高选择性的分离方法和高灵敏度的检测方法是制约这项研究广泛开展的原因之一。有机锡的痕量与超痕量分析技术是当今环境和食品安全分析领域的前沿技术。 本论文利用高效液相色谱和电感耦合等离子体质谱联用技术建立了海洋环境中多种有机化合物的同时快速检测方法;发展了多种海洋环境样品中有机锡的前处理技术;研究了有机锡在海洋生物中的分布、代谢及降解过程中化学形态的变化;同时发展了海洋环境中多种痕量元素的快速检测方法。所建立的高效液相色谱和电感耦合等离子体质谱联用技术可同时、快速分析5种有机锡的形态(三甲基锡TMT、二苯基锡DPhT、二丁基锡DBT、三丁基锡TBT和三苯基锡TPhT),其检出限均低于0.3μg/L。 用所建立方法对南海海洋生物样品中的有机锡污染进行了研究,利用SPSS软件对检测结果进行了探讨,发现在所研究海洋生物样品的97.2%中可检出丁基锡和苯基锡化合物,其浓度分布处于该化合物检出限~1487.8ng/g范围内。其中,贝类样品中总有机锡的平均浓度为416.9ng/g,远远高于鱼类样品中总有机锡的平均浓度(211.9ng/g)。海洋生物中存在高浓度的有机锡说明本海域有机锡污染严重,已经对生态环境造成了严重影响,危害到人类生活。其主要的污染源是防污涂料的应用,目前紧迫的问题是采取必要的措施来控制有机锡的使用。 本工作建立了海水样品和沉积物样品中五种有机锡的简单快速萃取方法。采用加入2%的环庚三烯酚(tropolone)的二氯甲烷CH2Cl2对海水中的有机锡进行萃取,大大提高了有机锡的萃取率,减少了萃取的时间,二苯基锡(DPhT)、二丁基锡(DBT)、三丁基锡(TBT)和三苯基锡(TPhT)的萃取率均在80%以上,仅三甲基锡(TMT)的萃取率较低(在50%左右),究其原因,可能是因为在萃取的过程中三甲基锡(TMT)产生了降解。采用流动相和0.2%环庚三烯酚酮(tropolone)对沉积物国际标准物质PACS-2进行超声萃取及高速离心后,用所建方法进行了分析。结果表明,测定值与标准值吻合。研究表明,所建立的方法可用于实际环境沉积物中有机锡的形态分析。 本文建立了流动注射与电感耦合等离子体质谱联用技术直接同时测定海水中多种痕量元素的方法。该方法采用痕量进样技术,能够有效地减少海水中Na,Mg, Ca和Cl等大量基体元素对待测痕量元素测定的干扰,减少这些元素在电感耦合等离子体采样锥上的盐沉积,可以同时测量海水中的V、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Mo、Cd、Pb,Hg和U等痕量级元素。用所建的方法测定南海海域海水中的重金属元素,发现Cd,Cr,As等有毒有害元素的污染很轻,均符合Ⅰ级海水的限量。 在海洋沉积物样品处理研究中,本工作改进了不需要赶走HF酸就可以对沉积物消解完全的密闭容器消解法,由于减少了赶走HF酸的步骤,使消解的时间由原来的二十个小时降低为十个小时,大大降低了消解的时间。采用该样品消解方法,并用ICP-MS测定了南黄海海域沉积物中锡及其他重金属元素的含量。建立了微波消解-ICP-MS测定海洋生物中锡、砷、镉、汞及铅等有害重金属元素的分析方法,并用于南黄海7个及南海海域29个海产品中的测定。测定结果表明海洋生物中上述有毒有害元素有不同程度的超标问题;不同种类,不同产地的海洋生物中重金属元素的含量有一定的差别,这些研究结果为海产品安全质量控制提供了有价值的科学信息。 在上述各章工作的基础上,本文研究了有机锡在海洋生物中的分布、代谢及降解过程,并初步建立了高效液相-电喷雾-飞行时间质谱(LC-APCI-TOF-MS)测定有机锡的方法,可对未知的有机锡化合物进行结构表征。有机锡在贝类中不同的组织显示,其内脏中有机锡的含量高于肌肉中有机锡含量。常规的煮、炸、蒸及微波的烹饪方式并不能降解海产品中的有机锡化合物。

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对含氮类光致发光分子2-(11H-苯[a]咔唑)-异丙基氯甲酸酯进行柱前衍生处理,并经荧光检测对脂肪胺进行高效液相色谱(HPLC)分离和质谱定性。衍生物于λ_(ex)=279nm产生强烈荧光,发射波长为λ_(ex)=380nm。40℃下在pH9.0的硼酸缓冲液中,衍生反应3min后获得稳定的荧光产物。在Eclipse XDB-C_8色谱柱(4.6mm×150mm,5μm)上,采用梯度洗脱对12种脂肪胺衍生物进行了优化分离。采用大气压化学电离源(APCI Source)正离子模式进行质谱定性,实现了各种脂肪胺衍生物的快速、准确测定。该方法具有良好的重复性,多数脂肪胺的线性回归系数大于0.9994,检出限在2.73~23.16fmol水平。

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采用新型荧光衍生试剂2-(11H-苯[a]咔唑)-乙酸(BCA)进行柱前衍生并经荧光检测对脂肪胺进行高效液相色谱(HPLC)分离和质谱定性。衍生物荧光激发和发射波长为λ_(ex)=285 nm,λ_(em)=384 nm。60℃下在乙腈溶剂中用N-乙基-N-[′(3-二甲氨基)丙基]碳二亚胺盐酸盐(EDC)作催化剂,衍生反应15 min后获得稳定的荧光产物。在Hypersil BDS C_(18)(4.0 mm×200 mm,10μm)色谱柱上,采用梯度洗脱对12种脂肪胺衍生物进行了优化分离。采用大气压化学电离源(APCI Source)正离子模式进行质谱定性,实现了各种脂肪胺衍生物的快速、准确测定。脂肪胺的线性回归系数不小于0.999 8,检出限(S/N=3)为5.73~31.3 fmol。

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合成了荧光衍生试剂1-[2-(对甲苯磺酸酯)乙基]-2-苯基咪唑[4,5-f]9,10-菲(TSEPIP),经衍生化和固相萃取制得了TSEPIP的辛酸衍生物(TSEPIP-C_8).研究了TSEPIP-C_8在包括溶剂极性、温度、卤素离子、重金属离子等不同的溶液环境因素影响下的荧光光谱性质,为高效液相色谱荧光分析检测提供了依据.在Eclipse XDB-C_8反相色谱柱上,在380 nm检测波长下采用梯度洗脱,实现了26种脂肪酸(FFA)TSEPIP衍生物的基线分离,应用该法完成了丹参中脂肪酸的含量分析.借助柱后串联质谱APCI大气压化学电离源正离子模式,能够实现各组分的快速定性.26种脂肪酸的线性回归系数均 》0.999 6,检出限为3.824~47.13 fmol(进样量10 μL,信噪比为3:1).

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含氮类荧光试剂2-(11H-苯[a]咔唑)乙基氯甲酸酯 (BCEC-Cl) 经柱前衍生处理后,采用荧光检测及柱后在线质谱鉴定对食品中胺类化合物进行了测定.标记反应在pH 9的硼酸缓冲液中进行,3 min后获得稳定的荧光产物.衍生物于λex=279 nm激发条件下产生强烈荧光,其发射波长在λem=380 nm处.产物的分离在Eclipse XDB-C8色谱柱 (150 mm×4.6 mm,5 μm)上进行,采用梯度洗脱对12种脂肪胺衍生物进行了优化分离.采用大气压化学电离源(APCI Source)正离子模式进行在线的柱后质谱鉴定,实现了多种脂肪胺衍生物的快速、准确测定.建立的方法具有良好的重现性,回归系数大于0.9996,检出限为1.8~14 fmol.

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用1-[2-(对甲苯磺酸酯)乙基]-2-苯基咪唑[4,5-f]9,10-菲(TSEPIP)作为柱前荧光衍生试剂,在Eclipse XDBC8(4.6×150 mm,5μm,Agilent)反相色谱柱上,采用梯度洗脱在检测波长为380nm(激发波长为260nm)的条件下,实现了阿拉斯加深海鱼油中饱和脂肪酸含量的外标法定量测定.26种饱和脂肪酸的线性范围是200.0pmol~48.83fmol,线性相关系数均大于0.9996,检测限为3.824~47.13 fmol(信噪比为3:1测得,S/N 3:1).经柱后串联质谱大气压化学电离源(APCI)正离子模式实现了各种饱和与不饱和脂肪酸衍生物的质谱鉴定,进而通过峰面积归一化法得出了所有饱和与不饱和脂肪酸的相对含量.结果表明,深海鱼油主要含有C12~C22的脂肪酸,共鉴定出25种脂肪酸,其中不饱和脂肪酸含量占69.71%(峰面积百分比,下同),特别是具有重要生理作用的多不饱和脂肪酸,如C20:5,8,11,14,17-二十碳五烯酸(5,8,11,14,17-eicosapentaenoic acid,EPA,16.62%),C22:6:2,5,8,11,14,17-二十二碳六烯酸(2,5,8,11,14,17-docosahexenoic acid,DHA,12.31%).

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采用新型荧光衍生试剂2-(2-苯基-1-氢-菲[9,10-d]咪唑)-乙酸(PPIA)进行柱前衍生,经荧光检测实现了脂肪胺的高效液相色谱(HPLC)分离测定及柱后质谱鉴定.60℃下在乙腈溶剂中用N-乙基-N′-[ (3-二甲氨基) 丙基 ]碳二亚胺盐酸盐(EDC)做缩合剂,衍生反应15 min可获得稳定的荧光产物.脂肪胺衍生物荧光检测波长为380 nm(激发波长为260 nm).在Eclipse XDB-C8 色谱柱上,采用梯度洗脱对12种脂肪胺衍生物进行了优化分离,测定了造纸厂废水、大鼠端脑和酸奶中脂肪胺的含量.经柱后在线质谱大气压化学电离源(APCI Source)正离子模式实现了各种脂肪胺衍生物的质谱鉴定,借助对活性中间体的质谱解析确定了衍生反应的反应机理.该方法具有良好的重现性和回收率,多数脂肪胺的线性回归系数大于0.9996;检出限为3.1~18 fmol (S/N=3∶ 1)

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以2-(2-(10-蒽基)-萘[2,3-d]咪唑)-乙基-对甲苯磺酸酯(ANITS)作为柱前衍生化试剂,在Eclipse XDB-C8色谱柱上,梯度洗脱实现了20种游离脂肪酸(FFA)衍生物的完全基线分离.90℃下在DMF溶剂中以K2CO3作催化剂,选取衍生试剂摩尔数为脂肪酸的7倍,衍生反应40 min可获得稳定的荧光产物.激发和发射波长分别为250 nm和512 nm.采用大气压化学电离源(APCI)正离子模式,实现了油菜蜂花粉中游离脂肪酸的质谱鉴定.所有脂肪酸的线性相关系数均大于0.9999, 检出限为24.76~98.79 fmol.