同位素比率质谱仪(isotope ratio mass spectrometers,IRMS)是近些年发展起来的用于测定某些稳定同位素组成的仪器,在诸多领域中都展现出广阔的应用前景。由于稳定同位素组成中蕴藏着丰富的地球化学信息,通过研究其组成可以揭示地球化...同位素比率质谱仪(isotope ratio mass spectrometers,IRMS)是近些年发展起来的用于测定某些稳定同位素组成的仪器,在诸多领域中都展现出广阔的应用前景。由于稳定同位素组成中蕴藏着丰富的地球化学信息,通过研究其组成可以揭示地球化学过程中的诸多方面的信息。所以IRMS技术和同位素一起作为一种新的有效手段在地球化学研究中有着越来越广泛的应用。本文主要介绍了该技术的原理,并结合相关碳氢等稳定同位素,分别讨论了与碳氢等稳定同位素在地球化学领域及相关学科中的应用。最后讨论了该技术的发展前景与目前存在的问题。展开更多
FT-ICR-MS technology has significant sensitivity and dynamic range,enabling the detection of different fragmentations of peptides and proteins at lower and lower levels.In the bottom-up approach,by far the most freque...FT-ICR-MS technology has significant sensitivity and dynamic range,enabling the detection of different fragmentations of peptides and proteins at lower and lower levels.In the bottom-up approach,by far the most frequently used proteomics approach,a single LC-MS run can reveal tens and even hundreds of useful information.For each peptide selected for MS/MS,two data-files were generated,one for ECD and another one for CAD.They were merged as described and submitted to the Mascot search engine using the protein database.These thresholds ensure almost 100% statistical confident in the peptide identification.展开更多
文摘同位素比率质谱仪(isotope ratio mass spectrometers,IRMS)是近些年发展起来的用于测定某些稳定同位素组成的仪器,在诸多领域中都展现出广阔的应用前景。由于稳定同位素组成中蕴藏着丰富的地球化学信息,通过研究其组成可以揭示地球化学过程中的诸多方面的信息。所以IRMS技术和同位素一起作为一种新的有效手段在地球化学研究中有着越来越广泛的应用。本文主要介绍了该技术的原理,并结合相关碳氢等稳定同位素,分别讨论了与碳氢等稳定同位素在地球化学领域及相关学科中的应用。最后讨论了该技术的发展前景与目前存在的问题。
文摘FT-ICR-MS technology has significant sensitivity and dynamic range,enabling the detection of different fragmentations of peptides and proteins at lower and lower levels.In the bottom-up approach,by far the most frequently used proteomics approach,a single LC-MS run can reveal tens and even hundreds of useful information.For each peptide selected for MS/MS,two data-files were generated,one for ECD and another one for CAD.They were merged as described and submitted to the Mascot search engine using the protein database.These thresholds ensure almost 100% statistical confident in the peptide identification.
