A process of fabricating a discrete-dynode electron multiplier (DDEM) including the steps of mounting an insulator block to a conductor block, and forming a series of ion-optics geometrical structures in the conductor block, each ion-optics geometrical structure having a smallest dimension of less than 1 millimeter. The forming step may be performed by electrical discharge machining (EDM), laser cutting, and/or water jet cutting.

A process of fabricating a discrete-dynode electron multiplier (DDEM) including the steps of mounting an insulator block to a conductor block, and forming a series of ion-optics geometrical structures in the conductor block, each ion-optics geometrical structure having a smallest dimension of less than 1 millimeter. The forming step may be performed by electrical discharge machining (EDM), laser cutting, and/or water jet cutting.

A first-stage dynode is a first-stage dynode to be used in a photomultiplier tube, and includes a bottom wall portion and a pair of side wall portions extending from both end portions of the bottom wall portion in a predetermined direction to one side. An electron emission surface is formed by a bottom surface of the bottom wall portion on the one side and a pair of side surfaces of the pair of side wall portions on the one side, and each of the pair of side surfaces is a curved surface that is curved in a concave shape in a cross section parallel to the predetermined direction.

A first-stage dynode is a first-stage dynode to be used in a photomultiplier tube, and includes a bottom wall portion and a pair of side wall portions extending from both end portions of the bottom wall portion in a predetermined direction to one side. An electron emission surface is formed by a bottom surface of the bottom wall portion on the one side and a pair of side surfaces of the pair of side wall portions on the one side, and each of the pair of side surfaces is a curved surface that is curved in a concave shape in a cross section parallel to the predetermined direction.

Described herein is a kit of materials prepared for assays that involve determining relative abundance and/or absolute abundance of various targeted peptides. The kit may comprise trigger versions of target peptides with masses offset from the respective target peptides by predetermined and known amounts. The trigger peptides may be present in amounts that may be readily detected via a mass spectrometry analysis. When mixed with samples that are analyzed, detection of the trigger peptides indicates where in the mass-spectrometer output the target peptide may be found. The kit may include a predetermined amount of synthetic versions of one or more of the target peptides. A measured relative abundance of this synthetic peptide relative to that of the target peptides yields an absolute quantitative value of the target peptide. Also disclosed is a method of preparing a plurality of samples to be submitted for mass spectrometer analysis in parallel.

Described herein is a kit of materials prepared for assays that involve determining relative abundance and/or absolute abundance of various targeted peptides. The kit may comprise trigger versions of target peptides with masses offset from the respective target peptides by predetermined and known amounts. The trigger peptides may be present in amounts that may be readily detected via a mass spectrometry analysis. When mixed with samples that are analyzed, detection of the trigger peptides indicates where in the mass-spectrometer output the target peptide may be found. The kit may include a predetermined amount of synthetic versions of one or more of the target peptides. A measured relative abundance of this synthetic peptide relative to that of the target peptides yields an absolute quantitative value of the target peptide. Also disclosed is a method of preparing a plurality of samples to be submitted for mass spectrometer analysis in parallel.

The present embodiment relates to an ion detector provided with a structure for suppressing degradation over time in an electron multiplication mechanism in a multi-mode ion detector. The ion detector includes a dynode unit, a first electron detection portion including a semiconductor detector having an electron multiplication function, a second electron detection portion including an electrode, and a gate part. The first and second electron detection portions are capable of ion detection at different multiplication factors. The gate part includes at least a final-stage dynode as a gate electrode, and controls switching between passage and interruption of secondary electrons which are directed toward the first electron detection portion by adjusting a set potential of the gate electrode.

The present embodiment relates to an ion detector provided with a structure for suppressing degradation over time in an electron multiplication mechanism in the ion detector. The ion detector includes a dynode unit, serving as an electron multiplication mechanism, which multiplies secondary electrons which are emitted in response to incidence of ions, and a semiconductor detector having an electron multiplication function. Further, a focus electrode having an opening that allows passage of secondary electrons is disposed on a trajectory of secondary electrons which are directed from the dynode unit toward the semiconductor detector, and the focus electrode functions to guide secondary electrons from the dynode unit onto an electron incidence surface of the semiconductor detector.

A secondary electron multiplier includes: a conversion dynode for emitting a secondary electron in response to an incident ion; a plurality of dynodes configured to have multi-stages from second to final stages for receiving the secondary electron; and a first voltage applying device for applying a first negative voltage to the conversion dynode and sequentially dividing the first negative voltage to apply to each of the second-stage and subsequent dynodes, wherein the secondary electron multiplier is configured to sequentially multiply the emitted secondary electron by the second-stage and subsequent dynodes. In the secondary electron multiplier, any of the second-stage and subsequent dynodes have a second voltage applying device for applying a second negative voltage. The secondary electron multiplier has an improved ion detection efficiency without a large reduction of a usable period thereof, thereby enhancing the sensitivity of a mass spectrometer.

A secondary electron multiplier includes: a conversion dynode for emitting a secondary electron in response to an incident ion; a plurality of dynodes configured to have multi-stages from second to final stages for receiving the secondary electron; and a first voltage applying device for applying a first negative voltage to the conversion dynode and sequentially dividing the first negative voltage to apply to each of the second-stage and subsequent dynodes, wherein the secondary electron multiplier is configured to sequentially multiply the emitted secondary electron by the second-stage and subsequent dynodes. In the secondary electron multiplier, any of the second-stage and subsequent dynodes have a second voltage applying device for applying a second negative voltage. The secondary electron multiplier has an improved ion detection efficiency without a large reduction of a usable period thereof, thereby enhancing the sensitivity of a mass spectrometer.