The LCMS-IT-TOF is a new type of mass spectrometer that combines QIT (ion trap) and TOF (time-of-flight) technologies. When combining QIT and TOF, the greatest technological challenges were the efficient introduction of ions into the QIT and the simultaneous ejection of trapped ions to the TOF. Here, we introduce the newly developed technologies used to solve these problems.
The source design, desolvation capillary and reduced collision ion focusing Q-Array were adapted from Shimadzu‘s successful single-quad HPLC mass spectrometer. The Octapole Lens can introduce eluted ions from the LC to the ion trap by CII (Compressed Ion Injection) method efficiently. The ion trap QIT gives an efficient MSn capability with our new cleaning technology. In addition, BIE (Ballistic Ion Extraction) technology, provides high resolution / accuracy for all MS, MSn... modes. The temperature control of the flight tube gives a mass stability with stabilizing the length of the ion flight and ion acceleration voltage which affects the mass stability. Dual-Stage Reflectron gives a excellent resolution with optimizing energy absorption and time convergence.
High-Speed and High-Accurate MSn Measurement
High-Speed Ion Polarity Switching Mode
Compressed Ion Introduction (CII™)
The ion optical system used in the LCMS-IT-TOF leads to a novel ion introduction method referred to as Compressed Ion Introduction or CII, where the combination of the skimmer, octopole and first lens converts the continuous stream of ions into pulses for introduction into the ion trap. This method makes it possible to control the accumulation of ions before they are introduced into the ion trap, allowing the RF to be applied to the ring electrode at the instant that all of the CII-accumulated ions enter the ion trap. This new method of controlling the ion trap, which is quite different from a traditional ion trap, is adopted for the LCMS-IT-TOF. The development of this CII effectively couples the LC system to the MS and enables a dramatic improvement over the previously deficient ion capture rate of the ion trap, thereby increasing sensitivity.
The LCMS-IT-TOF adopts the widely used ESI method for ionization, but the APPI (Atmospheric Pressure Photoionization) and APCI (Atmospheric Pressure Chemical Ionization) methods have been added to provide more ionization options for low polarity substances. APPI (Atomospheric Pressure Photoionization) is ionization in which samples are ionized using ultraviolet light. APCI (Atmospheric Pressure Chemical Ionization) is ionization in which the analytical sample is subjected to a corona discharge. APPI achieves good ionization with low to moderate polarity compounds, while APCI is suitable for moderately polar substances, so further expansion of LCMS-IT-TOC applications can be expected using these ionization methods. Selection of the ionization method is based on the sample properties.