Study On Transmission Characteristics Of Radio Frequency Quadrupole Ion Guide For Proton Transfer Reaction Time-Of-Flight Mass Spectrometry

Radio frequency quadrupole ion guide (RF-QIG) is widely used in various mass spectrometry systems because of its simple structure and high transmission efficiency. In this study, the self-developed RF-QIG was successfully integrated into the proton transfer reaction time-of-flight mass spectrometry (PTR-TOF MS). Through the adjustment of variable radio frequency electric field, the transmission characteristics of the device in ions with different mass-charge ratio (m/z) at different operating frequencies and voltage amplitudes were investigated. The results showed that when the frequency was less than 1 MHz, the RF-QIG reported here couldn't transport ions with m/z less than 40, while H3O+(m/z 19) and H2O center dot H3O+(m/z 37) could obtain strong MS signals at 2.48 MHz and 3.43 MHz. In addition, for the ions with higher m/z, such as [C3H6O+ H](+)(m/z 59), [C6H6 + H](+)(m/z 79) and [C7H8 +H](+)(m/z 93), the strongest signals were all obtained at 2.48 MHz. The results of MATLAB-s numerical solution of the effective potential showed that when the voltage amplitude was constant, the higher the frequency was given, the lower the effective potential was obtained. Finally, the successful detection of the background air in the laboratory showed that RF-QIG could be used in the ion transportation of PTR-TOF MS system.