Research, Incorporated

Meridian Instruments, Inc.

Michigan State University

Christie G Enke

John F Holland

Richard D McLane

John T Stults

Lawrence W Janow

Bruce H Newcome

Michael R Davenport

Richard A Yost

George E Yefchak

James D Morrison

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. In a preferred embodiment the apparatus includes a mass defect detector which compares the actual arrival time of the ions with the calculated anticipated time of arrival and applies appropriate time delays from a selected one of a plurality of delta-mass tables. This causes the area or peak detection circuity to be turned on either slightly prior to or subsequent to the calculated times of arrival of each of the ions to thus cause each of the ions to be received clearly and completely within each data collection window. Preferred embodiments include combinations of analog or digital peak or area capture and analog or digital successive summations.

Integrating transient recorder apparatus for time array detection in

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.

Time-compressed chromatography in mass spectrometry

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.

High repetition rate transient recorder with automatic integration

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.

Combination of time resolution and mass dispersive techniques in mass

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%.

Growing community of inventors

East Lansing, MI, United States of America

Christie G Enke