A more comprehensive calibration involving m/z and peak shape has been developed to attain the high spectral accuracy necessary to achieve unique elemental composition determination. This approach can be applied for f...A more comprehensive calibration involving m/z and peak shape has been developed to attain the high spectral accuracy necessary to achieve unique elemental composition determination. This approach can be applied for formula determination at much lower resolution such as single or triple quadrupole mass spectrometers.展开更多
The robustness of such an approach was studied through the observation of long term stability in reported accurate masses and peak shapes,with and without re-tuning the MS instruments.In addition,limit of identificati...The robustness of such an approach was studied through the observation of long term stability in reported accurate masses and peak shapes,with and without re-tuning the MS instruments.In addition,limit of identification(the lowest amount of a compound necessary to elucidate its structure) is also evaluated via mass spectral library search,mass accuracy and spectral accuracy.With PFTBA calibration performed to each GC-MS run,mass accuracy better than 10 mu and spectral accuracy better than 99% can be achieved to help attain reliable formula determination.MS tune changes both mass calibration and spectral accuracy(MS peak shape) and recalibration is therefore required after the tune in order to maintain the same formula determination capability.The limit of identification is about 0.4 ng on column for all five compounds tested,comparable to NIST MS library search.The spectral accuracy needs to be above 98.0% to have correct formula as the top two hits.展开更多
文摘A more comprehensive calibration involving m/z and peak shape has been developed to attain the high spectral accuracy necessary to achieve unique elemental composition determination. This approach can be applied for formula determination at much lower resolution such as single or triple quadrupole mass spectrometers.
文摘The robustness of such an approach was studied through the observation of long term stability in reported accurate masses and peak shapes,with and without re-tuning the MS instruments.In addition,limit of identification(the lowest amount of a compound necessary to elucidate its structure) is also evaluated via mass spectral library search,mass accuracy and spectral accuracy.With PFTBA calibration performed to each GC-MS run,mass accuracy better than 10 mu and spectral accuracy better than 99% can be achieved to help attain reliable formula determination.MS tune changes both mass calibration and spectral accuracy(MS peak shape) and recalibration is therefore required after the tune in order to maintain the same formula determination capability.The limit of identification is about 0.4 ng on column for all five compounds tested,comparable to NIST MS library search.The spectral accuracy needs to be above 98.0% to have correct formula as the top two hits.
