共查询到18条相似文献,搜索用时 93 毫秒
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碳纤维离子化技术是一种新型敞开式质谱技术,可在开放式大气压环境下对各种形态的样品或样品表面物质进行检测,其分析成本低、通量高、简便、实时、快速,简化了工作流程,降低了样品的基质效应。该文从碳纤维离子化质谱技术的原理出发,介绍了影响其电离效率的主要因素,如碳纤维形态、碳纤维温度、碳纤维上所加电压、碳纤维与离子进样口的距离以及样品添加的方式,并对该技术近几年的改进和发展,及其在食品药品、法医毒物及生物样品、品种鉴别和环境分析等领域的应用进行了综述,详细介绍了其特点和优势。最后讨论了碳纤维离子化质谱技术存在的不足,以及未来可能的研究方向。 相似文献
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采用反相离子对高效液相色谱(HPLC)和电喷雾离子化质谱(ESI-MS)对系列长链烷基甲基萘磺酸盐(AMNS),包括己基甲基萘磺酸盐、辛基甲基萘磺酸盐、癸基甲基萘磺酸盐、十二烷基甲基萘磺酸盐、十四烷基甲基萘磺酸盐进行分析,通过液相色谱分离条件的优化,找到了最佳分析条件.紫外检测波长230 nm,流动相为甲醇和水混合物,流速为0.8 mL/min,采用梯度洗脱方式进行分析.线性梯度:0~40 min时甲醇-水体积为60:40,在40~70min时,甲醇-水体积比为100:0.样品分离度高,分离效果较好.用面积归一化法得到了样品各组分的相对百分含量.HPLC和ESI-MS是快捷、有效和可靠的分析和表征AMNS的方法. 相似文献
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常压敞开式离子化质谱(Ambient ionization mass spectrometry,AIMS)是指无需复杂样品前处理,并且可在开放环境下对样品进行解吸和离子化的质谱技术。随着该技术的逐渐成熟,其在临床医学诊断中的应用越来越广泛。该文综述了AIMS领域的各种技术在肿瘤组织诊断中的应用,并对未来进行了展望。 相似文献
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Hung Su Zong-Han Jiang Shu-Fen Chiou Jentaie Shiea Deng-Chyang Wu Sung-Pin Tseng Shu-Huei Jain Chung-Yu Chang Po-Liang Lu 《Molecules (Basel, Switzerland)》2022,27(9)
Ambient ionization mass spectrometry (AIMS) is both labor and time saving and has been proven to be useful for the rapid delineation of trace organic and biological compounds with minimal sample pretreatment. Herein, an analytical platform of probe sampling combined with a thermal desorption–electrospray ionization/mass spectrometry (TD-ESI/MS) and multivariate statistical analysis was developed to rapidly differentiate bacterial species based on the differences in their lipid profiles. For comparison, protein fingerprinting was also performed with matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) to distinguish these bacterial species. Ten bacterial species, including five Gram-negative and five Gram-positive bacteria, were cultured, and the lipids in the colonies were characterized with TD-ESI/MS. As sample pretreatment was unnecessary, the analysis of the lipids in a bacterial colony growing on a Petri dish was completed within 1 min. The TD-ESI/MS results were further performed by principal component analysis (PCA) and hierarchical cluster analysis (HCA) to assist the classification of the bacteria, and a low relative standard deviation (5.2%) of the total ion current was obtained from repeated analyses of the lipids in a single bacterial colony. The PCA and HCA results indicated that different bacterial species were successfully distinguished by the differences in their lipid profiles as validated by the differences in their protein profiles recorded from the MALDI-TOF analysis. In addition, real-time monitoring of the changes in the specific lipids of a colony with growth time was also achieved with probe sampling and TD-ESI/MS. The developed analytical platform is promising as a useful diagnostic tool by which to rapidly distinguish bacterial species in clinical practice. 相似文献
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Paul J. Dyson Andrew K. Hearley Brian F. G. Johnson J. Scott McIndoe Patrick R. R. Langridge-Smith 《Journal of Cluster Science》2001,12(1):273-283
Mass spectra of transition metal carbonyl cluster anions were recorded using laser desorption ionization time-of-flight (LDI-TOF) and electrospray ionization (ESI) techniques. The LDI spectra generally contain peaks corresponding the intact cluster together with extensive CO loss fragments ions whereas the ESI spectra exhibit peaks corresponding the intact cluster together with few (if any) CO loss fragment ions. The parameters of both techniques can be modified to vary the extent of fragmentation. In all cases no fragmentation of the metal core is observed. Overall, ESI is a more informative method for the analysis of these types of cluster anions. 相似文献
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Dr. Anyin Li Adam Hollerbach Qingjie Luo Prof. R. Graham Cooks 《Angewandte Chemie (International ed. in English)》2015,54(23):6893-6895
Relay electrospray ionization (rESI) from a capillary containing a sample solution (or from an array of such capillaries) is triggered by charge deposition onto the capillary. Suitable sources of primary ions, besides electrosprays, are plasma ion and piezoelectric discharge plasma sources. With no requirement for physical contact, high‐throughput sample screening is enabled by rapidly addressing individual secondary (sample) capillaries. Sub‐pL sample volumes can be loaded and sprayed. Polar analytes, including neurotransmitters, phosphopeptides, oligonucleotides, illicit drugs, and pharmaceutical compounds are successfully ionized by rESI with concentration sensitivities (0.1 ppb for acetylcholine) which are similar to nanoESI but absolute sensitivities are orders of magnitude better. Nonpolar analytes (steroids, alkynes) are ionized by rESI using an open‐tube secondary capillary and injecting electrolytically generated metal cations from the primary electrospray. 相似文献
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电化学反应是连续的动态变化过程,伴随着瞬时中间体和复杂结构物质的产生,因此,精确而有效地捕捉反应过程中的一系列产物,有助于准确推导其电化学反应机理,进而优化反应条件,提高反应效率.目前,主流的电化学在线监测技术包括光谱法、循环伏安法和线性极化曲线等,这些方法能够胜任反应过程中大部分物质的结构及组成变化检测,然而,为了更加系统和精确地掌握电化学反应过程中所有产物的信息,仍需进一步拓展实时、原位反应监测技术.质谱具有灵敏度高、选择性好、分析速度快、可以结构解析等特点,是一种理想的电化学反应研究手段.近年来,采用质谱法研究电化学反应机理的报道越来越多,尤其是采用以电喷雾离子源(Electrospray Ionization,ESI)及其衍生离子源为代表的常压离子源对电化学反应过程进行实时、原位监测已经成为研究热点.本综述主要介绍了近期发表的电化学-质谱联用技术,详细描述了其针对不同类型电化学反应监测要求而设计和开发的电化学离子源装置. 相似文献