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US 7,351,959 B2Granted
Mass analyzer systems and methods for their operation
AssigneesApplera Corporation, MDS Inc.
InventorsKevin M. Hayden, Marvin L. Vestal, Jennifer M. Campbell
Life of this patent
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Abstract
The present teachings relate to MALDI-TOF instruments, instrument components, and methods of operation thereof. In various aspects, the MALDI-TOF instrument can serve and be operated as a MS/MS instrument. In various embodiments, provided are MALDI-TOF instruments, and methods of operating one or more components of a MALDI-TOF instrument, that facilitate one or more of increasing sensitivity, increasing resolution, increasing dynamic mass range, increasing sample support throughput, and decreasing operational downtime.
Claims19
A mass analyzer system comprising:
- a sample support having a sample surface;
- an optical system configured to irradiate a sample on the sample surface with a pulse of energy such that the pulse of energy strikes a sample on the sample surface at an angle substantially normal to the sample surface;
- a MALDI ion source comprising;
- a first electrode spaced apart from the sample support;
- a second electrode spaced apart from the first electrode in a direction opposite the sample support holder;
- a third electrode spaced apart from the second electrode in a direction opposite the first electrode;
- and
- a power source electrically coupled to the sample support, the first electrode, the second electrode, and the third electrode and configured to:
- apply a first potential to the sample surface and a second potential to at least one of the first electrode and the second electrode to establish a non-extracting electric field at a first predetermined time substantially prior to striking a sample on the sample surface with a pulse of energy to form sample ions, the non-extracting electrical field substantially not accelerating sample ions in a direction away from the sample surface;
- change the electrical potential of at least one of the sample surface and the first electrode to establish a first extraction electric field at a second predetermined time subsequent to the first predetermined time, the first extraction electric field accelerating sample ions in a first direction away from the sample surface, the first extraction electric field accelerating sample ions in a first direction away from the sample surface along a first ion optical axis that is substantially coaxial with the pulse of energy;
- and
- apply a third potential to the second electrode to focus ions in a direction substantially perpendicular to the first direction;
- an ion deflector configured to deflect ions from the first ion optical axis and onto a second ion optical axis;
- a first time-of flight positioned between the ion deflector and a timed ion selector;
- the timed ion selector being positioned between the first time-of flight and a collision cell, the timed ion selector being positioned to receive ions traveling along the second ion optical axis and being configured to select ions for transmittal to the collision cell;
- a second time-of-flight positioned between the collision cell and a first ion detector;
- an ion mirror positioned between the second time-of-flight and the first ion detector;
- and
- a third time-of-flight positioned between the ion mirror and a second ion detector.
16 more elements
A method of operating a mass analyzer system having two or more modes of operation and an ion source comprising a sample support having a sample surface, a first electrode spaced apart from the sample support, a second electrode spaced apart from the first electrode in a direction opposite the sample support holder, and a third electrode spaced apart from the second electrode in a direction opposite the first electrode, the method comprising the steps of:
- selecting for a first mode of operation a first position of a time-focus plane of the ion source by application of a first electrical potential difference between the sample surface and the first electrode, by applying a first electrical potential to the sample surface and a second electrical potential to the first electrode, the direction z being substantially normal to the sample surface;
- irradiating a sample on the sample surface with a pulse of energy at an irradiation angle that is substantially normal to the sample surface to form sample ions by matrix-assisted laser desorption/ionization;
- focusing sample ions in a direction substantially perpendicular to the direction z by application of a third electrical potential to the second electrode;
- extracting sample ions in the direction z along a first ion optical axis which is substantially coaxial with the pulse of energy;
- deflecting sample ions from the first ion optical axis and onto a second ion optical axis for mass analysis using the first mode of operation on sample ions deflected onto the second ion optical axis;
- changing the mode of operation of the time-of-flight mass analyzer to a second mode of operation;
- and
- selecting for the second mode of operation a second position of a time-focus plane of the ion source by application of a first electrical potential difference between the sample surface and the first electrode, by applying a fourth electrical potential to the sample surface that is substantially equal to the first electrical potential and applying a fifth electrical potential to the first electrode;
- irradiating a sample on the sample surface with a pulse of energy at an irradiation angle that is substantially normal to the sample surface to form sample ions by matrix-assisted laser desorption/ionization;
- focusing sample ions in a direction substantially perpendicular to the direction z by application of a sixth electrical potential to the second electrode;
- extracting sample ions in a direction substantially normal to the sample surface along a first ion optical axis which is substantially coaxial with the pulse of energy;
- and
- deflecting sample ions from the first ion optical axis and onto a second ion optical axis for mass analysis using the second mode of operation on sample ions deflected onto the second ion optical axis.
10 more elements
Dependencies are inferred from the claim text.