A high voltage RF oscillator for driving multipole ion guides.
A high voltage RF oscillator circuit has been designed and constructed for driving multipole ion guides. The circuit is tunable from 500 kHz to 1.5 MHz by changing a capacitor and provides 0-1000 V(p-p) that is controlled by a 0-10 V input using a negative feedback circuit. This inexpensive circuit uses a set of high voltage transistors oscillating in tandem and does not require tuning of the resonance drive frequency as the oscillator automatically resonates at the (LC)(-1/2) frequency. Matrix-assisted laser desorption/ionization-Fourier transform mass spectrometry (MALDI-FTMS) mass spectra were acquired using this tunable RF oscillator circuit to allow transmission of protein ions in the 8.5-39 kDa range through the quadrupole ion guide from the ion source to the mass analyzer.
O'Connor
Peter B
PB
Department of Biochemistry, Boston University School of Medicine Mass Spectrometry Resource, Boston, Massachusetts 02118, USA. poconnor@bu.edu
Costello
Catherine E
CE
Earle
William E
WE
D004581:Electronics; D005583:Fourier Analysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation*; D014173:Transistors, Electronic