Abstract: A combined distance-of-flight mass spectrometry (DOFMS) and time-of-flight mass spectrometry (TOFMS) instrument includes an ion source configured to produce ions having varying mass-to-charge ratios, a first detector configured to determine when each of the ions travels a predetermined distance, a second detector configured to determine how far each of the ions travels in a predetermined time, and a detector extraction region operable to direct portions of the ions either to the first detector or to the second detector.

Abstract: Novel methods and instrumentation for mass spectrometry are described. Zoom-time of flight mass spectrometry (Zoom-TOF) allows increased mass resolution over a pre-determined specific range of masses. Methods for retrofitting traditional time-of-flight (TOF) and distance of flight (DOF) mass spectrometers are described, as well as novel instruments capable of performing Zoom-TOF analyses.

Abstract: A combined distance-of-flight mass spectrometry (DOFMS) and time-of-flight mass spectrometry (TOFMS) instrument includes an ion source configured to produce ions having varying mass-to-charge ratios, a first detector configured to determine when each of the ions travels a predetermined distance, a second detector configured to determine how far each of the ions travels in a predetermined time, and a detector extraction region operable to direct portions of the ions either to the first detector or to the second detector.

Abstract: Novel methods and instrumentation for mass spectrometry are described. Zoom-time of flight mass spectrometry (Zoom-TOF) allows increased mass resolution over a pre-determined specific range of masses. Methods for retrofitting traditional time-of-flight (TOF) and distance of flight (DOF) mass spectrometers are described, as well as novel instruments capable of performing Zoom-TOF analyses.

Abstract: A miniature linear ion trap (MLIT) with a length of less than 30 mm is provided for ion focusing in the axial plane. The MLIT has multipoles for applying an AC voltage to ions and tubular entrance and exit lenses for applying a DC voltage to the ions. In another aspect, MLIT includes electrodes within the tubular entrance and exit lenses for detection of image current. A method is also provided for applying voltage to the entrance and exit lenses for ion focusing.

Abstract: A distance-of-flight mass spectrometer (DOF-MS) imparts constant momentum acceleration to ions in an ion source and uses an ion mirror to enhance energy focusing. Embodiments of DOF-MS with ion mirror are shown. Further, a method of compensating for the dispersion of initial ion position and velocity in the ion source is discussed.

Abstract: A miniature linear ion trap (MLIT) with a length of less than 30 mm is provided for ion focusing in the axial plane. The MLIT has multipoles for applying an AC voltage to ions and tubular entrance and exit lenses for applying a DC voltage to the ions. In another aspect, MLIT includes electrodes within the tubular entrance and exit lenses for detection of image current. A method is also provided for applying voltage to the entrance and exit lenses for ion focusing.

Abstract: A distance of flight (DOF) approach to mass spectroscopy in which the resolution among the various ion masses is accomplished in space rather than time. A separate detector is associated with each ion mass resolution element. The DOF mass spectrometer can serve as one element in a tandem arrangement which has the capability to produce a full two-dimensional precursor/product spectrum for each bunch of ions extracted from the source. A “distance-of-flight” (DOF) mass analyzer is used in combination with time-of-flight (TOF) mass analysis for precursor and product dispersion. All the precursor ions can undergo a mass changing reaction simultaneously, while still retaining the essential information about the particular precursor m/z value from which each product ion m/z value emanated. Through the use of a two-dimensional detector, all the products ions from all the precursors can be detected for each batch of ions analyzed.

Abstract: A distance of flight (DOF) approach to mass spectrometry in which the resolution among the various ion masses is accomplished in space rather than time. A separate detector is associated with each ion mass resolution element. The DOF mass spectrometer can serve as one element in a tandem arrangement which has the capability to produce a full two-dimensional precursor/product spectrum for each bunch of ions extracted from the source. A “distance-of-flight” (DOF) mass analyzer is used in combination with time-of-flight (TOF) mass analysis for precursor and product dispersion. All the precursor ions can undergo a mass changing reaction simultaneously, while still retaining the essential information about the particular precursor m/z value from which each product ion m/z value emanated. Through the use of a two-dimensional detector, all the products ions from all the precursors can be detected for each batch of ions analyzed.

Abstract: Novel ion mirrors comprising, in a preferred embodiment, three cylinders, rectangles or truncated cones to improve the resolving power in the time-of-flight mass spectrometers over broad ion kinetic energy ranges. The achieved electric field is non-linear along the mirror axis and relatively homogeneous in the mirror off-axis directions. Combined with dimension optimization, in a preferred embodiment, the adjustment of only two parameters of element voltages can yield preferred electric field distribution to fit different ion optical systems.

Abstract: An electrical equivalent circuit is provided for an electrospray process. It is a series circuit which includes a power supply voltage (Vapp), a voltage (Vec) established at the electrochemical contact to the solution, a solution resistance (Rs), a constant current regulator which represents the processes of charge separation and charge transport in the gap between the spray needle aperture and the counter electrode, and a voltage (Vcn) caused by charge neutralization at the counter electrode. A current i, established by the constant current regulator flows throughout the entire circuit. Current-voltage curves are developed for each part of the circuit. From these it is shown that in the case where Rs is negligible (the power supply is connected directly to a conducting needle) the shape of the current-voltage curve is dictated by the constant current regulator established by the charge separation process, the gap, and the counter electrode.

Abstract: An integrating transient recorder for time array detection of ions within an ion source extraction. The arrival times of all ions having various mass-to-charge ratios are calculated and integrating or peak detecting circuitry is activated just prior to the calculated time of arrival of each ion, and then only for a time duration in accordance with a predetermined data collection time window sufficient to enable each ion mass value to be completely measured. An analog-to-digital converter converts the area or peak analog signal for each ion into a corresponding digital signal and outputs the digital signals to a plurality of FIFO buffers. The FIFO buffers are read out for each successive transient by a digital signal processor and summed over a predetermined number of sequential transients in a mass locked registry creating a file of ion intensities versus mass-to-charge ratio of all ions detected.

Abstract: A process and apparatus employing the time compression of chromatography in mass spectrometry with array detection in which the time compressed informatioin is deconvoluted by mathematical analysis for recovery of analytical information made inaccessible in the time compression and thereby resulting in a decrease in analysis time and improved component identification without loss of sensitivity.

Abstract: A system for high speed acquisition and storage of data from transient electrical signal waveforms sampled in time at a multiplicity of points, and where it is desired to collect and store data in real time in a mass storage unit, but where the data rate is in excess of the apparent rate at which data can be transferred to mass storage. The overall system employs two levels of data reduction, the first being digital integration (summation) and the second being data processing. In the digital summation section memory read and write cycles overlap for higher speed. In one embodiment, a charge-coupled device is employed as an input element to reduce the data rate prior to subsequent digital processing. The system is capable of recording all the intensities of all transients continuously without loss of data significance.

Abstract: Time of flight mass spectrometry techniques are simultaneously combined with path-bending spatial dispersion in magnetic- or electric-sector mass spectrometers to improve the mass resolution or, with an ion fragmentation region, to rapidly obtain multidimensional mass spectral data previously only obtainable by tandem mass spectrometry. The instrumentation generates data defining relationships between parent ions and daughter ions produced by fragmentation, metastable or induced, data to differentiate stable from metastable ions, and data to improve mass resolution. The subject time-resolved mass spectrometers can be combined with chromatography apparatus to obtain multidimensional MS/MS-type data during the relatively short duration of a single chromatographic peak.

Abstract: A tandem quadrupole-based mass spectrometer including a highly efficient intermediate fragmentation stage. The disclosed fragmentation stage employs collision-induced dissociation (CID), in an electrodynamic focus device, which may be a quadrupole operated in a broad band filter mode. The disclosed CID process occurs at low energy (e.g., less than 1 keV, but preferably 2 eV to 100 eV), and is quite different from the high energy (e.g, greater than 1 keV, and typically 3 keV to 10 keV) CID process in prior tandem instruments such as mass-analyzed ion kinetic energy spectrometry (MIKES) systems. The efficiency of the present CID fragmentation is as high as 65%.