Beussman D J, Vlasak P R, McLane R D, Seeterlin M A, Enke C G
Department of Chemistry, Michigan State University, East Lansing 48824, USA.
Anal Chem. 1995 Nov 1;67(21):3952-7. doi: 10.1021/ac00117a021.
A tandem time-of-flight (TOF) mass spectrometer has been designed to obtain complete MS/MS spectra from compounds eluting from a gas chromatograph. This application requires high spectral generation rate, unit mass resolution for both precursor selection and product spectra, and efficient ion utilization. These objectives are achieved by reflectron TOF mass separation in both stages and laser photoinduced dissociation as the ion fragmentation method. Careful timing of the laser pulse relative to ion extraction allows ions of a single m/z value up to m/z 1000 to be photodissociated while ions with adjacent m/z values are essentially unaffected. The convergent foci of the ion packet and laser pulse results in ion fragmentation efficiencies as high as 79%. An ion gate prevents the nonselected precursor ions from convoluting the product spectra. Product spectra can be generated at the maximum laser repetition rate (currently 200 Hz). To achieve unit mass resolution for all product m/z values simultaneously, a novel reflectron was designed for the second TOF stage.
已设计出一种串联飞行时间（TOF）质谱仪，用于从气相色谱仪洗脱的化合物中获取完整的二级质谱（MS/MS）谱图。此应用需要高光谱生成速率、前体选择和产物谱图的单位质量分辨率以及高效的离子利用率。通过在两个阶段采用反射式TOF质量分离以及激光光致解离作为离子碎裂方法来实现这些目标。相对于离子提取精确控制激光脉冲的时间，使得高达m/z 1000的单个m/z值的离子能够被光解离，而相邻m/z值的离子基本不受影响。离子包和激光脉冲的会聚焦点导致离子碎裂效率高达79%。离子门可防止未选定的前体离子干扰产物谱图。产物谱图可以在最大激光重复频率（目前为200 Hz）下生成。为了同时实现所有产物m/z值的单位质量分辨率，为第二个TOF阶段设计了一种新型反射器。
