Page 9 - Shimadzu LCMS-IT-TOF

High-Speed Ion Polarity Switching Mode [up to 2.5 Hz]

High-Speed Ion Polarity Switching can be especially useful when it Voltage change monitored with an oscilloscope
cannot be judged whether samples will be detected as positive or 10
8
negative ions. The LCMS-IT-TOF utilizes a newly developed, highly
3
accurate and stable power supply as well as a newly developed
4
high-voltage switch that allows for polarity switching in only 0.1 2
Time (sec)
sec or less (necessary for the sharp HPLC peaks available with the 0
-0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6
advances in high-speed chromatography). The maximum rate for -2
Voltage (kV) -6
polarity switching is 2.5 Hz, which allows for a pair of positive and -4
negative ion MS spectra to be obtained 2.5 times per second. -8
-10

High-Speed Ion Polarity Switching Mode Measurement Example

Total Ion Chromatogram
Positive/Negative Sum TIC Sample : glycosylceramide
Inten.(× 10,000,000)
Positive ion TIC
(C16,18,20,22,23,24:0-d18:1), (C24:1-d18:1)
Negative Ion TIC
Column : Imtakt Cadenza CD-C18
Mobile phase : 5 mM Acetic acid in methanol
2.5 Flow rate : 0.2 mL/min

0.0
0.0 2.5 5.0 7.5 min

Positive Ion Mass Chromatogram
Inten. (× 10,000,000)
722.55 832.66
750.58 806.65
906.27 820.66 722.5527
980.29 834.68
2.75ppm
2.5
[M+Na] +
Expected 722.5547
500 1000 1500 m/z
0.0
0.0 2.5 5.0 7.5 min
Negative Ion Mass Chromatogram
Inten. (× 10,000,000)
812.55 896.65
840.58 910.66
868.62 924.68
5.0 812.5475
922.66
3.02ppm
[M+TFA-H] -
Expected 812.5497
500 1000 1500 m/z
0.0
0.0 2.5 5.0 7.5 min
Provided by RIKEN

LCMS-IT-TOF
Liquid Chromatograph Mass Spectrometer 9