共查询到19条相似文献,搜索用时 46 毫秒
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脂类化合物的结构和功能与细胞生理过程密切相关,脂质结构的精确解析对探索脂质的生物学功能起着至关重要的作用。常压电离质谱技术的出现为常压敞开环境条件下的原位、实时、直接、快速生物脂质分析和组学研究提供了重要的手段。随着常压电离质谱技术在脂质分析和脂质组学研究的不断深入,对脂质结构特别是碳碳双键(C‖C)位置的精细解析就显得尤为重要。该文详细阐述了基于Paternò-Büchi反应、环氧化、臭氧诱导解离、紫外光解离的常压电离质谱技术,以及这些技术在脂质C‖C位置精确鉴定及异构体区分的应用,并展望了常压电离质谱在脂质化合物精确结构解析方面的发展趋势。 相似文献
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实时直接分析(Direct analysis in real time,DART)作为一种原位电离技术发展迅猛,其与质谱联用已成为热门的分析技术并广泛应用于法庭科学领域,如食品安全、爆炸物检测、毒物毒品分析和药物分析等方面。目前农药的常规检测方法已非常成熟,但引入原位电离-质谱联用技术可以拓宽检测范围,缩短检测时限。该文从实时直接分析质谱(DART-MS)技术的工作原理、检测条件优化及其在农药检测方面的应用进行综述,并对DART-MS的应用前景进行了展望。 相似文献
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真空紫外光电离源(VUV-PI)是一种普适性的质谱软电离源,真空紫外光电离质谱谱图无碎片、易解析、灵敏度高,适合于在线快速分析。真空紫外光电离质谱根据分析对象不同可以直接采用单光子电离或添加掺杂剂实现化学电离,能实现气、液、固体分析,也可实现成像分析。该文介绍了真空紫外光电离源的电离原理、光源类型,分析了光电离质谱灵敏度的影响因素及其技术改进措施,并阐述了真空紫外光电离质谱技术在环境污染物、化工产物在线分析、国家安全分析以及生物医学分析中的相关应用研究。最后,总结了真空紫外光电离源的优缺点,并对真空紫外光电离技术在性能和应用方面的发展前景进行了展望。 相似文献
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利用大气压化学萃取电离源质谱技术(EAPCI-MS)对吡啶类化合物的电离行为特征进行研究。实验显示,EAPCI-MS技术在常温常压条件下,无需样品预处理和任何辅助化学试剂,在质谱图中能同时检测到吡啶类化合物的质子化分子离子峰[M+H]+和分子离子峰M+·,并具有类似的二级碎裂机理。研究结果表明,EAPCI-MS技术具有不同于传统电离源质谱的裂解方式,同时兼具传统电喷雾电离(ESI)和大气压化学电离(APCI)的特征电离方式和行为,极大地提高了化学检测的选择性,增强了质谱分析的定性能力。该研究为吡啶类化合物的检测和鉴定提供了一种新方法,对吡啶类化合物的快速检测具有重要的应用价值和意义。 相似文献
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近年来,果汁掺伪问题日益突出。作为一种新型的实时鉴别方法,智能手术刀(IKnife)与快速蒸发电离质谱(REIMS)联用技术无需样品前处理即可解决这一问题。该文采用代谢组学指纹识别技术建立橙汁、苹果汁和葡萄汁的实时鉴别方法,并对其掺假水平进行预测。主成分分析-线性判别分析联用法建立的判别模型能够区分不同类型的果汁,排除20%交叉验证法的正确率为97.28%,未知样品实时鉴别正确率高达100%。筛选出不同果汁中的标志物,并对部分化合物进行鉴定。结果表明,此方法能够成功区分掺有10%-50%苹果汁和葡萄汁的橙汁。通过对比分析REIMS单极质谱和串联质谱(REIMS/MS)的检测结果,两种方法建立的偏最小二乘分析模型均能准确预测掺假水平(所有模型的R 2和Q 2均大于0.82)。与传统的REIMS方法相比,REIMS/MS的预测值更加精确。 相似文献
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Tong Liu Wei Wang Muyi He Fengming Chen Jialing Liu Minli Yang Wei Guo Feng Zhang 《Electrophoresis》2022,43(18-19):1841-1849
Sorghum is an important grain with a high economic value for liquor production. Tracing the geographical origin of sorghum is vital to guarantee the liquor flavor. Soldering iron-based rapid evaporative ionization mass spectrometry (REIMS) combined with chemometrics was developed for the real-time discrimination of the sorghum's geographical origin. The working conditions of soldering iron-based ionization were optimized, and then the obtained MS profiling data were processed using chemometrics analysis methods, including principal component analysis–linear discriminant analysis and orthogonal projection to latent structures discriminant analysis (OPLS-DA). A recognition model was established, and discriminations of sorghum samples from 10 provinces in China were achieved with a correct rate higher than 90%. On the basis of OPLS-DA, the specific ions of m/z 279.2327, 281.2479, and 283.2639 had relatively strong discrimination power for the geographical origins of sorghum. The developed method was successfully applied in the discrimination of sorghum origins. The results indicated that the soldering iron-based REIMS technique combined with chemometrics is a useful tool for direct, fast, and real-time ionization of poor conductivity samples and acquisition of metabolic profiling data. 相似文献
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Haixing Wang Ting Li Qing Shen Zhifang Liu You-Wei Chen Darong Huang Jiancheng Yu Long Wang 《Electrophoresis》2023,44(13-14):1057-1067
Liver cancer is generally considered the leading cause of cancer deaths worldwide, and hepatocellular carcinoma (HCC) contributes to more than 90% of liver cancers. The altered lipid metabolism for rapid cancer cell growth and tumor formation has been frequently proven. In this study, an ambient ionization mass spectrometry technique, rapid evaporative ionization mass spectrometry (REIMS) using a monopolar electric knife, called iKnife, was systematically optimized and employed for ex vivo analysis of 12 human HCC tumor tissue specimens together with the paired paracancerous tissue (PT) and noncancerous liver tissue (NCT) specimens. Nine free fatty acids and 34 phospholipids were tentatively identified according to their extract masses and/or tandem mass spectra. With the help of statistical methods, 7 free fatty acids and 10 phospholipids were distributed differently in 3 types of liver tissue specimens (95% confidence interval). The box plots showed these characterized lipid metabolites varied in PT, HCC, and NCT. Compared with PT and NCT, the upregulations of four common fatty acids FA 18:0, FA 20:4, FA 16:0, and FA 18:1, together with phospholipids PC 36:1, PE 38:3, PE (18:0/20:4), PA (O-36:1), PC (32:1), PC 32:0, PE 34:0, and PC (16:0/18:1), were found in HCC specimens. The sensitivity and specificity of the established statistic model for real-time HCC tumor diagnosis were 100% and 90.5%, respectively. This study demonstrated that the described REIMS technique is a potential method for rapid lipidomic analysis and characterization of HCC tumor tissue. 相似文献
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敞开式电离质谱(Ambient ionization mass spectrometry,AIMS)是指在大气压环境下,无需或只需简单的样品前处理即可对样品中目标物进行分析的质谱技术。AIMS具有简单、快速、无损和适用范围广等优势,被广泛应用于法医毒物分析领域。该文对敞开式电离(Ambient ionization,AI)技术进行了简单概述,将检材分为体内检材和体外检材两大类,综述了AIMS技术在不同类型检材毒物分析中的应用,并对其在法医毒物分析中的发展前景进行了展望。 相似文献
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Mass spectrometry using a laser ionization source has played a significant role in elemental analysis. Three types of techniques are widely used: high irradiance laser ionization mass spectrometry is capable of rapid determination of elements in solids; single particle mass spectrometry is a powerful tool for single particle characterization; and resonance ionization mass spectrometry is applied for isotope ratio measurements with high sensitivity and selectivity. In this review, the main features of the laser ablation process and plasma characterization by mass spectrometry are summarized. Applications of these three techniques for elemental analysis are discussed. 相似文献
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尿液作为一种易于获取的体内毒品检材,在吸毒人员快速筛查中被广泛应用。针对传统快速筛查技术存在假阳性率高、定量能力不足以及实验室质谱技术在快速检测中存在前处理复杂、检测耗时长、使用环境苛刻等问题,该文提出了一种基于敞开式直接电离质谱技术的生物样本快速检测方法。该研究采用探针式电喷雾离子源与便携式质谱仪联用快速检测平台,优化了喷雾电压和质谱入口毛细管温度,开发了高效快速的前处理技术。基于该平台和前处理技术,5种常规毒品(甲基苯丙胺、氯胺酮、可卡因、O^(6)-单乙酰吗啡和3,4-亚甲双氧甲基苯丙胺)的尿液加标溶液的检出限为0.5~30 ng/mL,且其中4种毒品定量检测的线性相关系数大于0.99。除此之外,5种常规毒品在3个不同水平下的加标回收率为56.1%~103.7%,多次检测结果的相对标准偏差为9.0%~27.8%,说明联用检测平台与前处理方法结合可以达到良好的准确度。为了进一步检验该联用仪器的实战能力,测试了某社区戒毒康复中心40份阳性和110份阴性实际尿液样本,总体检测的准确率接近99%,且通过一次进样在20 s内可同时检测多种毒品。该研究成果有利于推动快速检测技术的发展,促进敞开式直接电离质谱仪技术的推广应用,提升一线执法服务水平。 相似文献