使用Finnigan公司TSQ Quantum Ultra AM在色谱/时间尺度进行多肽和药物化合物的精确质量测量
前言：
Accurate mass (AM) measurements, within ± 5 ppm of the theoretical masses1, are routinely used for determining elemental compositions, elucidating the structure of unknown compounds, identifying metabolites and impurities, and determining fragmentation mechanisms2-4. Obtaining accurate mass data on a triple quadrupole has historically been very difficult due to the presence of unresolved isobaric impurities and the thermal instability of the r.f. electronics. Now, the enhanced mass-resolution HyperQuad™ quadrupoles and innovative electronic design of the Finnigan TSQ Quantum Ultra AM make it possible to routinely acquire accurate mass measurements on a triple quadrupole mass spectrometer. The experiments detailed in this work demonstrate the ability of the Finnigan TSQ Quantum Ultra AM through incorporating of the above-listed pre-requisites, to perform accurate mass measurements of various pharmaceutical compounds and peptides.
仪器：
结论：
Accurate Mass Measurement Using Internal Lock Masses The accurate mass measurement in positive ion mode is easily achieved by first calibrating the instrument using polytyrosine for standard calibration at unit mass resolution, followed by further calibration using ammoniated PEGs or phosphoric acid cluster ions at higher mass resolution, and then applying lock mass peaks to achieve a simple linear mass correction for the ions of interest. The same procedures apply in negative ion mode, except phosphoric acid cluster ions were used instead of ammoniated PEGs.
