An ion detector for secondary ion mass spectrometer, the detector having an electron emission plate coupled to a first electrical potential and configured to emit electrons upon incidence on ions; a scintillator coupled to a second electrical potential, different from the first electrical potential, the scintillator having a front side facing the electron emission plate and a backside, the scintillator configured to emit photons from the backside upon incidence of electrons on the front side; a lightguide coupled to the backside of the scintillator and confining flow of photons emitted from the backside of the scintillator; and a solid-state photomultiplier coupled to the light guide and having an output configured to output electrical signal corresponding to incidence of photons from the lightguide. A SIMS system includes a plurality of such detectors movable arranged over the focal plane of a mass analyzer.

A method for determining an amino acid sequence of a polypeptide, including comprising: contacting a first sample containing the polypeptide with a first protease(e.g., Trypsin) to produce a first set of digested peptide fragments; fragmenting the first set of digested peptide fragments to produce a first set of fragmented peptide ions; determining masses of the first set of fragmented peptide ions; contacting a second sample containing the polypeptide with a second protease (e.g., Tryp-N); fragmenting the second set of digested peptide fragments to produce a second set of fragmented peptide ions; selecting pairs of peptide ions from the first and the second set of fragmented peptide ions that differ in mass by a mass of an arginine amino acid residue or a lysine amino acid residue; assigning an ion type (either N-terminal peptide ion or C-terminal peptide ion) to the selected pairs of the peptide ions from two sets of fragmented peptide ions;selecting a mass ladder of the same-type peptide ions in either set of fragmented peptide ions with incremental mass by the mass of amino acid residue(s), and assembling the identified amino acid residues from the mass ladder to determine the amino acid sequence of the polypeptide of interest.

An accelerator mass spectrometry system for measuring an isotopic ratio of a chemical element in a sample. The system includes an ion source generating a beam of negative ions of the chemical element containing ions of first and second isotopes of the chemical element, a first analyzer section, comprising a first mass analyzer; a tandem accelerator comprising a first accelerating section, a charge stripping section for converting the negative ions into positive ions, and a second accelerating section behind the charge stripping section. A second analyzer section includes a second mass analyzer and an electrostatic analyzer; a particle detector; and a controller system configured to control the first mass analyzer section and the second analyzer section such that the ions of the first and second isotopes traverse the tandem accelerator and ions of only one of the first and second isotopes enter the particle detector. An additional analyzer is located in between the charge stripping section and the second accelerating section and is configured to receive positive ions that have exited the charge stripping section and to separate positive ions having a charge state corresponding to a predetermined charge-state value from positive ions having a charge state not corresponding to the predetermined charge-state value, so as to transmit ions with different charge states in mutually different directions such that only ions having a charge state corresponding to the predetermined charge-state value are transmitted towards the particle detector.

A low power mass spectrometer assembly includes at least an ionization component, an electrostatic analyzer, a lens assembly, a magnet assembly and at least one detector located in a same plane as the entrance to the magnet assembly for detecting the deflected sample ions and/or fragments of sample ions, including ions or ion fragments indicative of the Vitamin D metabolite within the sample.

A low power mass spectrometer assembly includes at least an ionization component, an electrostatic analyzer, a lens assembly, a magnet assembly and at least one detector located in a same plane as the entrance to the magnet assembly for detecting the deflected sample ions and/or fragments of sample ions, including ions or ion fragments indicative of the Vitamin D metabolite within the sample.

The present invention provides an accelerator mass spectrometry device for simultaneously measuring isotopes. In one embodiment, the device comprises a sputtering negative ion source for generating negative ions; the sputtering negative ion source being connected to an accelerating tube for simultaneously accelerating a plurality of isotopic ions; an output end of the accelerating tube being connected to an isotope mass resolution system; the isotope mass resolution system being connected to a charge conversion analysis and multi-receiving measurement system; the charge conversion analysis and multi-receiving measurement system being connected to an ion detection system. The present invention is capable of accelerating a plurality of isotopic negative ions simultaneously. The accelerated isotopic negative ions are separated. Stable isotopic negative ions are measured by a stable isotope receiver. Unstable isotope negative ions are converted to positive ions and then measured by a detector.

The present invention provides an accelerator mass spectrometry device for simultaneously measuring isotopes. In one embodiment, the device comprises a sputtering negative ion source for generating negative ions; the sputtering negative ion source being connected to an accelerating tube for simultaneously accelerating a plurality of isotopic ions; an output end of the accelerating tube being connected to an isotope mass resolution system; the isotope mass resolution system being connected to a charge conversion analysis and multi-receiving measurement system; the charge conversion analysis and multi-receiving measurement system being connected to an ion detection system. The present invention is capable of accelerating a plurality of isotopic negative ions simultaneously. The accelerated isotopic negative ions are separated. Stable isotopic negative ions are measured by a stable isotope receiver. Unstable isotope negative ions are converted to positive ions and then measured by a detector.

A method and a system, the system, comprising a laser source, a ionization and acceleration unit, a separation unit, and a collecting unit, wherein the laser source comprises a large bandwidth laser delivering successive pulses of fixed central wavelength and bandwidth to a surface of a target positioned inside the ionization and acceleration unit, surface atoms of the target being ionized by the pulses, accelerated from the surface of the target to a kinetic energy in the range between 100 eV and 10 KeV, and focused to the separation unit, the separation unit separating received atoms into different ions species, and the collecting unit separately collecting the different ion species. The method comprises positioning a target inside a resistive tube, delivering successive pulses of same selected wavelength and bandwidth from a large bandwidth laser generating a beam of fixed central wavelength and bandwidth to a surface of the target to ionize atoms of the surface of the target, accelerate the ionized atoms to a kinetic energy in a range between 100 eV and 10 KeV, under an electric field in a resistive tube, directing the ionized atoms to a magnetic separator, and collecting ions species of the target separately in cup collectors.

The present invention comprises novel methods of continuously monitoring the performance of an atmospheric pressure ionization (API) system. The methods of the invention allow for improved quality monitoring of the processes that leads to the formation of ions at atmospheric pressure. The methods of the invention further allow for continuously monitoring for the quality of the ion formation process in API without the addition of extraneous material (such as labelled compounds or control known compounds) to the system being monitored.

The present invention comprises novel methods of continuously monitoring the performance of an atmospheric pressure ionization (API) system. The methods of the invention allow for improved quality monitoring of the processes that leads to the formation of ions at atmospheric pressure. The methods of the invention further allow for continuously monitoring for the quality of the ion formation process in API without the addition of extraneous material (such as labelled compounds or control known compounds) to the system being monitored.