Provided is a time-of-flight mass spectrometer including: a loop-orbit defining electrode (21) including an outer electrode (211) and inner electrode (212) located on the outside and inside of a loop orbit, respectively; an ion inlet (22); an ion outlet (23) provided in either the outer or inner electrode; a loop-flight voltage applier (28) configured to apply loop-flight voltages to the outer and inner electrodes, respectively; a set of deflecting electrodes (24) facing each other across a section of an n-th loop orbit, where n is a predetermined number, the deflecting electrodes including a first portion (241) which faces the n-th loop orbit and a second portion (242) which includes other portions; and a voltage applier (29) configured to apply deflecting voltages to the first portion so as to reverse the drifting direction of the ions flying in the n-th loop orbit, and a voltage to the second portion so as to create the loop-flight electric field.

A method of performing time-of-flight secondary ion mass spectrometry on a sample includes the step of directing a beam of primary ions to the sample, and stimulating the migration of ions within the sample while the beam of primary ions is directed at the sample. The stimulation of the ions is cycled between a stimulation state and a lower stimulation state. Secondary ions emitted from the sample by the beam of primary ions are collected in a time-of-flight mass spectrometer. Time-of-flight secondary ion mass spectrometry is then performed on the secondary ions. A system for performing time-of-flight secondary ion mass spectrometry on a sample is also disclosed.

A method of selecting ions comprises selecting ions corresponding to a target ion of interest by separating analyte ions according to their ion mobility, isolating first ions of the analyte ions, separating the first ions according to their ion mobility, and isolating second ions of the first ions. Preferably, the separation is accomplished by using a cyclic or closed-loop separator.

A Time of Flight mass analyser is disclosed comprising: at least one ion mirror ((34) for reflecting ions; an ion detector (36) arranged for detecting the reflected ions; a first pulsed ion accelerator (30) for accelerating an ion packet in a first dimension (Y-dimension) towards the ion detector (36) so that the ion packet spatially converges in the first dimension as it travels to the detector (36); and a pulsed orthogonal accelerator (32) for orthogonally accelerating the ion packet in a second, orthogonal dimension (X-dimension) into one of said at least one ion mirrors (34).

A system and computer program product are provided for calculating one or more indicative properties, e.g., one or more of the cetane number, octane number, pour point, cloud point, octane number, and aniline point of oil fractions, from the density and time of flight mass spectrometry (TOF-MS) of a sample of an oil sample.

A multi-reflecting time of flight mass analyser is disclosed in which the ion flight path is maintained relatively small and the duty cycle is made relatively high. Spatial focusing of the ions in the dimension (z-dimension) in which the mirrors (36) are elongated can be eliminated whilst maintaining a reasonably high sensitivity and resolution.

Provided is a method for mass spectrometry in which ions to be analyzed are made to come in contact with a cooling gas in a cooling section, such as an ion trap 2, configured to perform the cooling of ions, and kinetic energy is subsequently imparted to the ions so as to introduce the ions into a flight space of a multi-turn time-of-flight mass separator 30 or similar device for separating ions according to their mass-to-charge ratios. According to the present invention, when a known or estimated number of charges of an ion to be analyzed is high, the amount of supply of the cooling gas to the cooling section is set to a lower level than when the number of charges is low. This operation improves the detection sensitivity for ions having large molecular weights and high numbers of charges.

An MT-TOFMS which is one mode of the present invention includes: a linear ion trap (2) configured to temporarily hold ions to be analyzed, and to eject the ions through an ion ejection opening (211) having a shape elongated in one direction; a loop flight section (3) configured to form a loop path (P) capable of making ions repeatedly fly; and a slit part (5) located on an ion path in which the ions ejected from the linear ion trap (2) travel until the ions are introduced into the loop path, the slit part configured to block a portion of the ions in a longitudinal direction of the ion ejection opening (211).

A Time of Flight mass analyser is disclosed comprising: at least one ion mirror 34 for reflecting ions; an ion detector 36 arranged for detecting the reflected ions; a first pulsed ion accelerator 30 for accelerating an ion packet in a first dimension (Y-dimension) towards the ion detector 36 so that the ion packet spatially converges in the first dimension as it travels to the detector 36; and a pulsed orthogonal accelerator 32 for orthogonally accelerating the ion packet in a second, orthogonal dimension (X-dimension) into one of said at least one ion mirrors 34.

Disclosed herein is an ion analysis instrument comprising a Time of Flight (“TOF”) mass analyser comprising a reflectron. The instrument is operable in at least a first mode and a second mode, wherein in said first mode ions are caused to turn around at a first point in the reflectron and wherein in said second mode ions are caused to turn around at a second point in the reflectron such that the distance traveled by ions within the Time of Flight mass analyser is greater in the second mode than the distance traveled by ions within the Time of Flight mass analyser in the first mode. In this way, the operating modes can be selectively optimised for the analysis of ions of different masses.