Johns Hopkins University

Scott A Ecelberger

Timothy J Cornish

Wayne A Bryden

Charles W Anderson

Harvey Wayne Ko

Robert J Cotter

John C Murphy

Michael P McLoughlin

Micah A Carlson

Robert Osiander

Peter F Scholl

Dennis K Wickenden

Robert B Givens

William R Allmon

Thomas J Kistenmacher

Daniel J DeCicco

James T Velky

Nicholas H Evancich

Ronald G Chappell

A mass spectrometer is provided herein and is configured to have two ionization sources, in which a first ionization source, such as MALDI, ESI and the like, which is capable of providing in addition to ions a set of normally intractable desorbed neutrals that are ionized by a second EI source coupled with the first source.

Combined chemical/biological agent detection system and method utilizing mass spectrometry

A method is provided for reducing signal ringing in a microchannel plate detector assembly having a cylindrical mount with a center tube extending through at least a portion of the assembly, in a mass spectrometer including the steps of providing the microchannel plate detector assembly with a pin anode extending from the cylindrical mount and located in proximity to the center tube; holding a front portion of the assembly at ground potential; setting a middle portion of the assembly between the front portion and a rear portion to a first voltage potential for accelerating ions; holding the rear portion of the assembly to a second voltage potential; holding the pin anode at a third voltage potential; and accelerating electrons emitted from the middle portion of the assembly toward the pin anode. The third voltage potential is established by an amplifier of an oscilloscope connected to the detector assembly.

Microchannel plate detector assembly for a time-of-flight mass spectrometer

Techniques for simultaneously detecting direct and reflected ions in a time-of-flight tube () and a source () for generating an ion beam of ions of a sample and introducing the ion beam into a first portion of the flight tube. A reflector () reflects ions from the ion beam in a second portion of the flight tube. A plate () substantially perpendicular to an axis of the ion beam is located between the first portion of the flight tube and the second portion of the flight tube. The plate has a hole through which some ions in the ion beam may pass from the first portion to the second portion of the flight tube. Each of two opposite faces of the plate includes a set of one or more ion detectors (). The technique allows rapid, reliable detection of complex agents in a small number of samples.

Mass spectrometer for simultaneous detection of reflected and direct ions

A field portable mass spectrometer system comprising a sample collector and a sample transporter. The sample transporter interfaces with the sample collector to receive sample deposits thereon. The system further comprises a time of flight (TOF) mass spectrometer. The time of flight mass spectrometer has a sealable opening that receives the sample transported via the sample transporter in an extraction region of the mass spectrometer. The system further comprises a control unit that processes a time series output by the mass spectrometer for a received sample and identifies one or more agents contained in the sample.

Portable time-of-flight mass spectrometer system

Sample collection preparation methods for time-of flight miniature mass spectrometer

A time-of-flight mass spectrometer (TOF-MS) array instrument is provided. Each TOF-MS of the array instrument includes (1) a gridless, focusing ionization extraction device allowing for the use of very high extraction energies in a maintenance-free design, (2) a fiberglass-clad flexible circuit-board reflector using rolled flexible circuit-board material, and (3) a low-noise, center-hole microchannel plate detector assembly that significantly reduces the noise (or &ldquo;ringing&rdquo;) inherent in the coaxial design. The miniature TOF-MS array allows for the bundling of a plurality of mass analyzers, e.g., a plurality of TOF-MSs, into a single array working in parallel fashion to greatly enhance the throughput of each TOF-MS in the array by multiplexing the data collection process. A preferred embodiment of the TOF-MS array instrument incorporates 16 TOF-MS units that are arranged in mirror-image clusters of eight units.

Time-of-flight mass spectrometer array instrument

A microelectromechanical-based magnetostrictive magnetometer that uses, as an active element, a commercial (001) silicon microcantilever coated with an amorphous thin film of the giant magnetostrictive alloy Terfenol-D and a compact optical beam deflection transduction scheme. A set of Helmholtz coils is used to create an ac magnetic excitation field for driving the mechanical resonance of the coated microcantilever. When the coated microcantilever is placed in a dc magnetic field, the dc field will change the amplitude at the mechanical resonance of the coated microcantilever thereby causing a deflection that can be measured. The magnetometer has been demonstrated with a sensitivity near 1 .mu.T.

Microelectromechanical (MEMS)-based magnetostrictive magnetometer

Growing community of inventors

Laurel, MD, United States of America

Scott A Ecelberger