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.

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.

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.

A low power mass spectrometer (LPMS) includes an ionization source for generating an ionized sample beam; ion focusing optics for focusing the sample beam; and a static magnetic field region contained within an electric field-free drift region created between magnets acting as equipotential electrodes combined with a third equipotential surrounding electrode for receiving the focused sample beam and deflecting ions therein to different points on a detector array in accordance with an individual mass thereof. The LPMS operates at less than 1.2 Watts and has a physical footprint equal to or less than 12 inches at its largest length.

A low power mass spectrometer (LPMS) includes an ionization source for generating an ionized sample beam; ion focusing optics for focusing the sample beam; and a static magnetic field region contained within an electric field-free drift region created between magnets acting as equipotential electrodes combined with a third equipotential surrounding electrode for receiving the focused sample beam and deflecting ions therein to different points on a detector array in accordance with an individual mass thereof. The LPMS operates at less than 1.2 Watts and has a physical footprint equal to or less than 12 inches at its largest length.

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.

A low power mass spectrometer (LPMS) includes an ionization source for generating an ionized sample beam; ion focusing optics for focusing the sample beam; and a static magnetic field region contained within an electric field-free drift region created between magnets acting as equipotential electrodes combined with a third equipotential surrounding electrode for receiving the focused sample beam and deflecting ions therein to different points on a detector array in accordance with an individual mass thereof. The LPMS operates at less than 1.2 Watts and has a physical footprint equal to or less than 12 inches at its largest length.

A low power mass spectrometer (LPMS) includes an ionization source for generating an ionized sample beam; ion focusing optics for focusing the sample beam; and a static magnetic field region contained within an electric field-free drift region created between magnets acting as equipotential electrodes combined with a third equipotential surrounding electrode for receiving the focused sample beam and deflecting ions therein to different points on a detector array in accordance with an individual mass thereof. The LPMS operates at less than 1.2 Watts and has a physical footprint equal to or less than 12 inches at its largest length.

A low power mass spectrometer (LPMS) includes an ionization source for generating an ionized sample beam; ion focusing optics for focusing the sample beam; and a static magnetic field region contained within an electric field-free drift region created between magnets acting as equipotential electrodes combined with a third equipotential surrounding electrode for receiving the focused sample beam and deflecting ions therein to different points on a detector array in accordance with an individual mass thereof. The LPMS operates at less than 1.2 Watts and has a physical footprint equal to or less than 12 inches at its largest length.