| 摘要 |
A method of mass spectrometry or ion mobility spectrometry is disclosed comprising: providing ions towards an ion storage region 10; selecting a target maximum charge desired to be stored within the ion storage region 10 at any given time; and reducing the ion current passing to the ion storage region 10 such that the ions entering the ion storage region 10 do not cause the total charge within the storage region 10 to rise above said target maximum charge, where the step of reducing the ion current passing to the ion storage region 10 comprises: temporally separating the ions according to a first physico-chemical property (e.g. ion mobility in an ion mobility separator 4); and filtering the ions according to a second physico-chemical property (e.g. mass to charge ratio with a mass filter 6); the steps of separating and filtering the ions result in substantially only target ions having selected combinations of first and second physico-chemical properties being transmitted towards the ion storage region 10; and accumulating the target ions within the ion storage region 10 during an ion accumulation period. Also disclosed is a similar method where the ions are provided to towards an ion reaction region in place of an ion storage region 10. Further disclosed are mass spectrometers comprising an ion source 2; an ion storage/reaction region 10 having a target maximum storage charge; an ion separator 4 and ion filter 6 between the ion source 2 and ion region 10; and a control means arranged and configured to allow the spectrometer to perform the above method. |
