Analytical performance of a venturi device integrated into an electrospray ionization fourier transform ion cyclotron resonance mass spectrometer for analysis of nucleic acids.
A voltage-assisted venturi device modeled after an industrial air amplifier was used to improve the ion transmission efficiency of a 16.2 kDa oligonucleotide and a 53-mer PCR product in the high-pressure region between an electrospray ionization (ESI) emitter and the sampling orifices of two Fourier transform ion cyclotron resonance mass spectrometers (FT-ICR-MS). The venturi device increased the total ion abundance of the oligonucleotide and the PCR product by more than 6-fold relative to the best achievable signal without the device. Furthermore, the average charge states of the oligonucleotide and PCR product shifted from 12.5- to 14.5- and 10.9- to 12.6-, respectively, with the addition of the venturi device. Specific to FT-ICR mass spectrometry, this increase in the charge state directly translates to an increase in theoretical mass resolving power (>10000 full width half-maximum for the results presented here at 7 T). Adduction was still observed while using the device, suggesting that it is "soft" relative to other high-pressure ion focusing methods.
Hawkridge
Adam M
AM
Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
Zhou
Li
L
Lee
Milton L
ML
Muddiman
David C
DC
D017357:Cyclotrons; D005583:Fourier Analysis; D013058:Mass Spectrometry / Q000295:instrumentation* / Q000379:methods; D009841:Oligonucleotides / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D009841:Oligonucleotides