Fast Multidimensional (3D and 4D) MS² and MS³ Scans in a High-Transmission Pentaquadrupole Mass Spectrometer

Abstract

A high-transmission Extrel pentaquadrupole mass spectrometer was interfaced to an IBM-compatible microcomputer, and a variety of object-oriented programs in the Microsoft Windows operating system were developed to operate and to increase the versatility of the instrument. A selective prescan procedure and the complete control of all three mass-scanning quadrupoles made possible very fast acquisition of several types of three- and four-dimensional MS2 and MS3 spectra, while the high transmission of the quadrupoles conferred excellent signal-to-noise levels to both MS2 and MS3 spectra. By performing an unrestricted third-order (MS3) experiment through scanning of the three mass-analyzer quadrupoles, an entire MS3 data domain was acquired, and the results were collected in the first 4D MS3 mass spectrum. Data projection and data extraction procedures were applied to the 4D spectrum, each of which yielded spectra that provide very specific analytical information. The applicabilities of this and several other multidimensional mass scans were further demonstrated, particularly toward the study of gas phase ion chemistry processes. A consecutive MS3 neutral gain/neutral loss scan was for the first time applied and proved to be very selective for the detection of acylium ions in the gas phase. The application of a 3D MS2 scan, applied in conjunction with the membrane introduction mass spectrometry technique, for fast and simultaneous qualitative, quantitative, and structural analyses of volatile organic compounds in water was also demonstrated.