共查询到20条相似文献,搜索用时 703 毫秒
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加速溶剂提取凝胶渗透色谱净化气相色谱质谱快速测定玉米中多环芳烃 总被引:12,自引:2,他引:10
研究了玉米中16种多环芳烃的快速分析方法.采用加速溶剂萃取法(ASE)对玉米样品进行提取,提取溶剂为二氯甲烷,萃取池中依次加入3 g中性氧化铝吸附剂和10 g待测样品,提取的同时能够在线净化除去小分子杂质.收集的提取液进一步用凝胶渗透色谱(GPC)除去样品中大分子油脂和色素,流动相为二氯甲烷,流速为3 mL/min,收集9~13 min的流出液,提取液浓缩定容至1 mL后用GC-SIM-MS进行分析.16种 PAHs以及4种替代物在2个浓度水平添加时的平均添加回收率在55.7%~145.3%之间; RSD为1 4%~16.8%;方法检出限为0.005~0.120 ng/g.本方法简便、快速、准确,净化效果较好,满足残留分析的要求,且能应用于其它谷物样品的日常分析. 相似文献
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用于气相色谱和气相色谱-质谱测定植物样品中含氯有机污染物残留的样品前处理方法 总被引:3,自引:0,他引:3
根据植物样品中的主要干扰物质,建立了用于气相色谱(GC)和气相色谱-质谱联用(GC-MS)测定植物样品中含氯有机污染物残留的样品前处理方法,有效提高了对植物样品中有机氯农药及多氯联苯检测的灵敏度。采用均质提取法对样品进行提取,考察了凝胶渗透色谱(GPC)和固相萃取(SPE)对提取液的净化效果。结果发现,采用GC测定目标物时,提取液需经GPC和SPE两次净化;而采用GC-MS测定目标物时,仅用SPE一次净化即可。该方法快速、经济、灵敏,适合多种植物样品中有机污染物残留分析的样品前处理要求。 相似文献
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《理化检验(化学分册)》2010,(7)
采用加速溶剂萃取(ASE)及凝胶色谱(GPC)在线净化,实现了土壤中六六六及滴滴涕的8种异构体或同系物残留量的气相色谱-质谱(GC-MS)联用快速测定。以二氯甲烷-丙酮(1+1)为溶剂,采用加速溶剂萃取土壤样品,萃取液经合并,蒸干后溶于10 mL丙酮中,通过GPC-GC-MS联用仪可实现净化后直接在线检测,检测模式为离子监测(SIM)模式,利用保留时间和特征离子进行定性,外标法定量。在此检测方法下,8种有机氯农药在0.02~0.4 mg.L-1范围内呈线性关系,检出限(3S/N)在0.014 7~0.078 3μg.kg-1之间,加标回收率在101.4%~129.5%范围内。 相似文献
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建立了索氏提取-硅胶柱和凝胶柱净化/气相色谱-质谱联用(GC-MS)测定植物叶片中多环芳烃的分析方法。叶片中的多环芳烃经二氯甲烷-正己烷(体积比1∶1)索氏提取,提取液采用硅胶柱和凝胶柱两步净化(手填硅胶柱和GPC柱)后,进行GC-MS测定,根据保留时间和特征离子进行定性,内标法定量。方法检出限为0.025 1~5.80 ng/g,加标回收率为82.2%~130%,相对标准偏差不大于11%。该方法能有效去除植物叶片中的色素与油脂,适用于植物叶片中多组分多环芳烃的痕量分析,为测定植物组织内多环芳烃的含量提供了技术支撑。 相似文献
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贻贝中多氯联苯分析的前处理方法研究 总被引:7,自引:0,他引:7
针对分析贻贝中痕量多氯联苯(PCBs),比较了索氏提取(SE)和加速溶剂萃取(ASE)两种提取方法,结果表明SE对贻贝中7种PCBs(PCB28、PCB52、PCB101、PCB118、PCB153、PCB138、PCB180)回收率范围在96%~125%,ASE回收率范围在102%~115%,两者提取效果相当,但与索氏提取相比,加速溶剂萃取是一种怏速、高效的提取方法此外采用凝胶渗透色谱(GPC)分别与Florisil和C18固相萃取(SPE)小柱联用净化,GPC与Florisil柱联用净化的凹收率范围在90%-112%,GPC与C18柱联用净化的回收率范围在74%-108%,结果表明GPC与Florisil柱联增净化优于GPC与C18柱联用净化。 相似文献
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《Analytical letters》2012,45(19-20):1963-1971
Abstract FAB-MS/MS methods are used to quantify the neuropeptide leucine enkephalin (LE = YGGFL) in synthetic solutions. Maximum molecular specificity is provided by monitoring two metastable transitions from the LE (M + H)+, 556 → 425 and 556 → 336, in a forward geometry (E, B) mass spectrometer using a B/E linked-field selected reaction monitoring technique. Obtained sensitivity is 40 pg LE, which equals 72 fmol. The statistics of the best-fit straight lines are, for m/z 425: y = 34 + 166 (r = 0.999), and for m/z 336: y = 2.5x + 17.2 (r = 0.996). 相似文献
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Domingues MR Domingues P Reis A Ferrer-Correia AJ Tomé JP Tomé AC Neves MG Cavaleiro JA 《Journal of mass spectrometry : JMS》2004,39(2):158-167
Porphyrin derivatives having a galactose or a bis(isopropylidene)galactose structural unit, linked by ester or ether bonds, were characterized by electrospray tandem mass spectrometry (ES-MS/MS). The electrospray mass spectra of these glycoporphyrins show the corresponding [M + H](+) ions. For the glycoporphyrins with pyridyl substituents and those having a tetrafluorophenyl spacer, the doubly charged ions [M + 2H](2+) were also observed in ES-MS with high relative abundance. The fragmentation of both [M + H](+) and [M + 2H](2+) ions exhibited common fragmentation pathways for porphyrins with the same sugar residue, independently of the porphyrin structural unit and type of linkage. ES-MS/MS of the [M + H](+) ions of the galactose-substituted porphyrins gave the fragment ions [M + H - C(2)H(4)O(2)](+), [M + H - C(3)H(6)O(3)](+), [M + H - C(4)H(8)O(4)](+) and [M + H - galactose residue](+). The fragmentation of the [M + 2H](2+) ions of the porphyrins with galactose shows the common doubly charged fragment ions [porphyrin + H](2+), [M + 2H - C(2)H(4)O(2)](2+), [M + 2H - C(4)H(8)O(4)](2+), [M + 2H - galactose residue](2+) and the singly charged fragment ions [M + H - C(3)H(6)O(3)](+) and [M + H - galactose residue](+). The fragmentation of the [M + H](+) ions of glycoporphyrins with a protected galactosyl residue leads mainly to the ions [M + H - CO(CH(3))(2)](+), [M + H - 2CO(CH(3))(2)](+), [M + H - 2CO(CH(3))(2) - CO](+), [M + H - C(10)H(16)O(4)](+) and [M + H - protected galactose](+). The doubly charged ions [M + 2H](2+) fragment to give the doubly charged ions [porphyrin + H](2+) and the singly charged ions [M + H - protected galactose residue](+) and [M + H - CO(CH(3))(2)](+). For the porphyrins where the sugar structural unit is linked by an ester bond, [M + 2H](2+), ES-MS/MS showed a major and typical fragmentation corresponding to combined loss of a sugar structural unit and further loss of water, leading to the ion [M + 2H - sugar residue - H(2)O](2+), independently of the structure of the sugar structural unit. These results show that ES-MS/MS can be a powerful tool for the characterization of the sugar structural unit of glycoporphyrins, without the need for chemical hydrolysis. 相似文献
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该文总结了二次离子质谱、基质辅助激光解吸电离质谱和常压敞开式离子化质谱三大类型质谱分子成像(MSI)技术的概况、技术与方法及其应用新进展。MSI技术作为免标记、高覆盖、高灵敏、检测范围广的可视化分析手段,不局限于生物组织或细胞中某种特定分子的检测,可对已知和未知多种分子进行同时成像分析,获得不同分子的空间分布、相对含量及结构信息,实现其分子的定性、定量与定位分析;还可提供不同生理及病理过程中功能分子的动态时空变化信息等。因此,MSI技术成为质谱领域以及分析化学等领域的研究前沿与热点方向之一,并在化学、医学、生命科学、药学和环境科学等领域显示出重大应用前景。此外,MSI技术是单细胞可视化分析和空间分辨代谢组学的强有力分析手段,可从动物或器官组织的整体、微区、单细胞等不同空间尺度,获取具有空间分布特征、时空动态变化的功能分子全景轮廓信息等而备受关注。 相似文献
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Silva EM Domingues MR Barros C Faustino MA Tomé JP Neves MG Tomé AC Santana-Marques MG Cavaleiro JA Ferrer-Correia AJ 《Journal of mass spectrometry : JMS》2005,40(1):117-122
The zinc complexes of diaryl bis(p-nitrophenyl)porphyrins and beta-(1,3-dinitroalkyl)tetraphenylporphyrins were studied by electrospray ionization (ESI) tandem mass spectrometry (MS/MS). All porphyrins showed the protonated molecule under ESI conditions. The protonated molecules were induced to fragment and the corresponding ESI tandem mass spectra were analysed. Porphyrins with two p-nitrophenyl groups showed, as expected, characteristic fragmentations including either loss of one nitro group, as the major fragment of the tandem mass spectra, and loss of both nitro groups. In contrast, MS/MS of the beta-(1,3-dinitroalkyl)porphyrins provided interesting and unexpected results such as the absence (or in insignificant abundance) of the ions formed by loss of one nitro group. However, these porphyrins show an abundant fragment due to combined loss of the two nitro groups. Also, the typical beta-cleavage of the alkyl chain is not observed per se, only when combined with loss of HNO2 or *NO2. Instead, alpha-cleavage, with loss of the beta-pyrrolic substituent, is the most favourable process. 相似文献
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食品中胆固醇色谱/质谱/质谱的测定 总被引:3,自引:0,他引:3
确立了用色谱/质谱/质谱测定食品中胆固醇的一种新方法,试样经乙酸乙酯提取后,GC/MS/MS测定分析,以胆固醇分子离子为母离了,以其子离子为定量分析的碎片离子。线性好,回收率高,方法可靠。 相似文献
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Kai Guo Zaihong Guo James M. Ludlow Tingzheng Xie Shengyun Liao George R. Newkome Chrys Wesdemiotis 《Macromolecular rapid communications》2015,36(17):1539-1552
Top‐down multidimensional mass spectrometry, interfacing electrospray ionization (ESI) with ion mobility mass spectrometry (IM‐MS), and energy resolved (gradient) tandem mass spectrometry (gMS2) are employed to characterize the stoichiometries, architectures, and intrinsic stabilities of coordinatively bound supramolecular polymers containing terpyridine functionalized ligands. As a soft ionization method, ESI prevents or minimizes unwanted assembly destruction. The IM dimension affords separation of the supramolecular ions by charge and collision cross‐section (a function of size and shape). The mobility separated ions are subsequently identified by their mass‐to‐charge‐ratios and isotope patterns in the orthogonal MS dimension. Finally, the gMS2 dimension reveals bond breaking proclivities and disintegration pathways of the assemblies. The described methodology does not require high sample purity due to the dispersive nature of the IM and MS steps. Its utility is demonstrated with the comprehensive analysis of bisterpyridine‐based metallomacrocycle mixtures and a tristerpyridine based complex with 3‐D nanosphere‐like architecture.
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用激光解吸质谱法和快原子轰击质谱法分析研究Al-酞青和Cu,Ni,Zn4,4',4'',4'''-四羧基酞青化合物,四羧基取代酞青由于四个羧基取代导致酞青极大增大和挥发点增高,较难用于FAB法测定,但用基体帮助激光解吸质谱法可得到满意的结果,而一般铝酞青化合物分别用FAB和MALD法都可获得满意结果,但FAB法能获得更多碎片信息。 相似文献
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应用碰撞诱导解离(CID)技术研究了电子轰击方法产生的脂肪胺分子离子和化学电离方法产生的质子化脂肪胺分子的碎裂反应。质子化脂肪胺碰撞活化后的主要碎裂通道包括丢失C_XH_(2X)、C_XH_(2X 1)、C_XH_(2X 2)单元及NH_3和生成[C_yH_(2y 1)]及CH_3CH=NH_2~ 离子。脂肪胺分子离子碰撞活化后的主要碎裂通道是丢失C_XH_(2X)、C_XH_(2X 1)及NH_3和生成[C_mH_(2m-1)]~ 、CH_2NH_2~ 及CH_3CHNH_2~ 离子。随着碰撞能的增加,远电荷碎裂反应和电荷诱导碎裂反应之间竞争引起产物离子的的分布发生变化,如[C_mH_(2m-1)]~ 和[C_yH_(2y 1)]~ 离子。自由基机理可以解释质子化脂肪胺分子的远电荷反应。分子内氢抽取可以解释脂肪胺分子离子的碎裂反应。 相似文献
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芹菜素的电喷雾萃取电离串联质谱 总被引:3,自引:0,他引:3
采用实验室自制的电喷雾萃取电离源(EESI),结合串联质谱(MSn)技术,对芹菜素这一典型的黄酮类活性化合物的质谱行为进行了研究。实验表明,在正、负离子检测模式下,该化合物均能得到较好的EESI-MS信号,且在负离子检测模式下灵敏度更高。通过对比芹菜素的EESI-MS和电喷雾电离质谱(ESI-MS)谱图发现,芹菜素在EESI-MS和ESI-MS中的裂解规律相似,但是EESI是一种比ESI更软的电离模式。根据对芹菜素EESI-MS特征碎片离子的分析,提出了芹菜素在EESI-MS中裂解的基本规律,为EESI-MS技术用于分析、鉴定复杂基质中痕量芹菜素奠定了理论和实验基础。 相似文献