- UFswitching(high-speed positive/negative ionization mode switching)
To detect both positive ions and negative ions, measurements are performed while switching alternately between positive and negative ionization modes. With the LCMS-2020, ultra high-speed polarity switching is achieved by adopting a high voltage power source loaded with groundbreaking technology (patent pending).
In MS scanning, a range of mass to charge ratios are determined in successive 0.1 m/z steps. This is controlled by applying a rapidly changing voltage to the quadrupole (quadrupole rods). By adopting new technology (patent pending), high ion transmission is achieved without sacrificing sensitivity or resolution, even during high-speed scans up to 15,000 u/sec. Very narrow UFLC peaks can now be properly detected in scan mode acquisition.
Superior sensitivity, repeatability, and linearity are achieved, due to Qarray® optics.
- LCMS-2020 also provide a dual ion source simultaneously ionizes samples using two ionization methods – electrospray ionization (ESI ), which is suitable for high polarity compounds, and atmospheric pressure chemical ionization ( APCI ), which is suitable for low-to-medium polarity compounds. Therefore, it is capable of ionizing a wide range of compounds, including chemical classes from low to high polarity.
Samples sent to the dual ion source are ionized by an electrospray ionization (ESI) probe, and simultaneously ionized by an atmospheric pressure chemical ionization (APCI) corona discharge needle located below the ESI outlet. This is useful when it is desirable to analyze compounds suited to both ESI and APCI in the same analytical run. Because both the ESI and APCI voltages operate continuously, no switching time is required, and the DUIS performs analysis with high reliability and reproducibility without loss of data, even for analyses with narrow peaks obtained using ultra fast liquid chromatography.
The DUIS-2020 dual ion source option has a simple structure and is easy to maintain. The DUIS-2020 voltages can be independently controlled and its data processed using LCMSsolution software for LCMS-2020 systems.
For further information: http://www.shimadzu.com/an/lcms/lcms2020/2020.html