Note: Claims are shown in the official language in which they were submitted.
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Claims
1. A mass spectrometer comprising:
a mass filter for separating ions according to
their mass to charge ratio, said mass filter comprising
at least seven electrodes wherein, in use, an AC or RF
voltage is applied to said electrodes in order to
radially confine ions within said mass filter and
wherein in use one or more transient DC voltages or one
or more transient DC voltage waveforms are progressively
applied to said electrodes so that at least some ions
having a first mass to charge ratio are separated from
other ions having a second different mass to charge
ratio which remain substantially radially confined
within said mass filter.
2. A mass spectrometer as claimed in claim 1, wherein
said mass filter is maintained, in use, at a pressure
selected from the group consisting of: (i) greater than
or equal to 1x10 -7 mbar; (ii) greater than or equal to
5x10 -7 mbar; (iii) greater than or equal to 1x10 -6 mbar;
(iv) greater than or equal to 5x10 -6 mbar; (v) greater
than or equal to 1x10 -5 mbar; and (vi) greater than or
equal to 5x10 -5 mbar.
3. A mass spectrometer as claimed in claim 1 or 2,
wherein said mass filter is maintained, in use, at a
pressure selected from the group consisting of: (i) less
than or equal to 1x10 -4 mbar; (ii) less than or equal to
5x10 -5 mbar; (iii) less than or equal to 1x10 -5 mbar;
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(iv) less than or equal to 5x10 -6 mbar; (v) less than
equal to 1x10 -6 mbar; (vi) less than or equal to 5x10 -7
mbar; and (vii) less than or equal to 1x10 -7 mbar.
4. A mass spectrometer as claimed in claim 1, 2 or 3,
wherein said mass filter is maintained, in use, at a
pressure selected from the group consisting of: (i)
between 1x10 -7 and 1x10 -4 mbar; (ii) between 1x10 -7 and
5x10 -5 mbar; (iii) between 1x10 -7 and 1x10 -5 mbar; (iv)
between 1x10 -7 and 5x10 -6 mbar; (v) between 1x10 -7 and
1x10 -6 mbar; (vi) between 1x10 -7 and 5x10 -7 mbar; (vii)
between 5x10 -7 and 1x10 -4 mbar; (viii) between 5x10 -7 and
5x10 -5 mbar; (ix) between 5x10 -7 and 1x10 -5 mbar; (x)
between 5x10 -7 and 5x10 -6 mbar; (xi) between 5x10 -7 and
1x10 -6 mbar; (xii) between 1x10 -6 mbar and 1x10 -4 mbar;
(xiii) between 1x10 -6 and 5x10 -5 mbar; (xiv) between 1x10-
6 and 1x10 -5 mbar; (xv) between 1x10 -6 and 5x10 -6 mbar;
(xvi) between 5x10 -6 mbar and 1x10 -4 mbar; (xvii) between
5x10 -6 and 5x10 -5 mbar; (xviii) between 5x10 -6 and 1x10 -5
mbar; (xix) between 1x10 -5 mbar and 1x10 -4 mbar; (xx)
between 1x10 -5 and 5x10 -5 mbar; and (xxi) between 5x10 -5
and 1x10 -4 mbar.
5. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltages or
one or more transient DC voltage waveforms is such that
at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or
95% of said ions having said first mass to charge ratio
are substantially moved along said mass filter by said
one or more transient DC voltages or said one or more
transient DC voltage waveforms as said one or more
transient DC voltages or said one or more transient DC
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voltage waveforms are progressively applied to said
electrodes.
6. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms are such
that at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%,
90% or 95% of said ions having said second mass to
charge ratio are moved along said mass filter by said
applied DC voltage to a lesser degree than said ions
having said first mass to charge ratio as said one or
more transient DC voltages or said one or more transient
DC voltage waveforms are progressively applied to said
electrodes.
7. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms are such
that at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%,
90% or 95% of said ions having said first mass to charge
ratio are moved along said mass filter with a higher
velocity than said ions having said second mass to
charge ratio.
8. A mass spectrometer comprising:
an mass filter for separating ions according to
their mass to charge ratio, said mass filter comprising
at least seven electrodes wherein, in use, an AC or RF
voltage is applied to said electrodes in order to
radially confine ions within said mass filter and
wherein in use one or more transient DC voltages or one
or more transient DC voltage waveforms are progressively
applied to said electrodes so that ions are moved
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towards a region of the mass filter wherein at least one
electrode has a potential such that at least some ions
having a first mass to charge ratio will pass across
said potential whereas other ions having a second
different mass to charge ratio will not pass across said
potential but will remain substantially radially
confined within said mass filter.
9. A mass spectrometer as claimed in claim 8, wherein
said one or more transient DC voltages or said one or
more transient DC voltage waveforms are such that at
least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%
of said ions having said first mass to charge ratio pass
across said potential.
20. A mass spectrometer as claimed in claim 8 or 9,
wherein said one or more transient DC voltages or said
one or more transient DC voltage waveforms are such that
at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or
95% of said ions having said second mass to charge ratio
will not pass across said potential.
11. A mass spectrometer as claimed in claim 8, 9 or 10,
wherein said at least one electrode is provided with a
voltage such that a potential hill or valley is
provided.
12. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms are such
that at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%,
90% or 95% of said ions having said first mass to charge
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ratio exit said mass filter substantially before ions
having said second mass to charge ratio.
13. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms are such
that at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%,
90% or 95% of said ions having said second mass to
charge ratio exit said mass filter substantially after
ions having said first mass to charge ratio.
14. A mass spectrometer as claimed in any preceding
claim, wherein a majority of said tons having said first
mass to charge ratio exit said mass filter a time t
before a majority of said ions having said second mass
to charge ratio exit said mass filter, wherein t falls
within a range selected from the group consisting of:
(i) < 1 µs; (ii) 1-10 µs; (iii) 10-50 µs; (iv) 50-100
µs; (v) 100-200 µs; (vi) 200-300 µs; (vii) 300-400 µs;
(viii) 400-500 µs; (ix) 500-600 µs; (x) 600-700 µs; (xi)
700-800 µs; (xii) 800-900 µs; (xiii) 900-1000 µs.
15. A mass spectrometer as claimed in any of claims 1-
13, wherein a majority of said ions having said first
mass to charge ratio exit said mass filter a time t
before a majority of said ions having said second mass
to charge ratio exit said mass filter, wherein t falls
within a range selected from the group consisting of:
(i) 1.0-1.5 ms; (ii) 1.5-2.0 ms; (iii) 2.0-2.5 ms; (iv)
2.5-3.0 ms; (v) 3.0-3.5 ms; (vi) 3.5-4.0 ms; (vii) 4.0-
4.5 ms; (viii) 4.5-5.0 ms; (ix) 5-10 ms; (x) 10-15 ms;
(xi) 15-20 ms; (xii) 20-25 ms; (xiii) 25-30 ms; (xiv)
30-35 ms; (xv) 35-40 ms; (xvi) 40-45 ms; (xvii) 45-50
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ms; (xviii) 50-55 ms; (xix) 55-60 ms; (xx) 60-65 ms;
(xxi) 65-70 ms; (xxii) 70-75 ms; (xxiii) 75-80 ms;
(xxiv) 80-85 ms; (xxv) 85-90 ms; (xxvi) 90-95 ms;
(xxvii) 95-100 ms; and (xxviii) > 100 ms.
16. A mass spectrometer comprising:
a mass filter for separating ions according to
their mass to charge ratio, said mass filter comprising
a plurality of electrodes wherein, in use, an AC or RF
voltage is applied to said electrodes in order to
radially confine ions within said mass filter and
wherein in use one or more transient DC voltages or one
or more transient DC voltage waveforms are progressively
applied to said electrodes so that:
(i) ions are moved towards a region of the mass
filter wherein at least one electrode has a first
potential such that at least some ions having first and
second different mass to charge ratios will pass across
said first potential whereas other ions having a third
different mass to charge ratio will not pass across said
first potential; and then
(ii) ions having said first and second mass to
charge ratios are moved towards a region of the mass
filter wherein at least one electrode has a second
potential such that at least some ions having said first
mass to charge ratio will pass across said second
potential whereas other ions having said second
different mass to charge ratio will not pass across said
second potential.
17. A mass spectrometer as claimed in claim 16, wherein
said one or more transient DC voltages or said one or
more transient DC voltage waveforms and said first
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potential are such that at least 10%, 20%, 30%, 40%,
50%, 60%, 70%, 80%, 90% or 95% of said ions having said
first mass to charge ratio pass across said first
potential.
18. A mass spectrometer as claimed in claim 16 or 17,
wherein said one or more transient DC voltages or said
one or more transient DC voltage waveforms and said
first potential are such that at least 10%, 20%, 30%,
40%, 50%, 60%, 70%, 80%, 90% or 95% of said ions having
said second mass to charge ratio pass across said first
potential.
19. A mass spectrometer as claimed in claim 16, 17 or
18, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms and said
first potential are such that at least 10%, 20%, 30%,
40%, 50%, 60%, 70%, 80%, 90% or 95% of said ions having
said third mass to charge ratio do not pass across said
first potential.
20. A mass spectrometer as claimed in any of claims 16-
19, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms and said
second potential are such that at least 10%, 20%, 30%,
40%, 50%, 60%, 70%, 80%, 90% or 95% of said ions having
said first mass to charge ratio pass across said second
potential.
21. A mass spectrometer as claimed in any of claims 16-
20, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms and said
second potential are such that at least 10%, 20%, 30%,
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40%, 50%, 60%, 70%, 80%, 90% or 95% of said ions having
said second mass to charge ratio do not pass across said
second potential.
22. A mass spectrometer as claimed in any of claims 16-
21, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms are such
that at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%,
90% or 95% of said ions having said second mass to
charge ratio exit said mass filter substantially before
ions having said first and third mass to charge ratios.
23. A mass spectrometer as claimed in any of claims 16-
22, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms are such
that at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%,
90% or 95% of said ions having said first and third mass
to charge ratios exit said mass filter substantially
after ions having said second mass to charge ratio.
24. A mass spectrometer as claimed in any of claims 16-
23, wherein a majority of said ions having said second
mass to charge ratio exit said mass filter a time t
before a majority of said ions having said first and
third mass to charge ratios exit said mass filter,
wherein t falls within a range selected from the group
consisting of: (i) < 1 µs; (ii) 1-10 µs; (iii) 10-50 µs;
(iv) 50-100 µs; (v) 100-200 µs; (vi) 200-300 µs; (vii)
300-400 µs; (viii) 400-500 µs; (ix) 500-600 µs; (x) 600-
700 µs; (xi) 700-800 µs; (xii) 800-900 µs; (xiii) 900-
1000 µs.
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25. A mass spectrometer as claimed in any of claims 16-
23, wherein a majority of said ions having said second
mass to charge ratio exit said mass filter a time t
before a majority of said ions having said first and
third mass to charge ratios exit said mass filter,
wherein t falls within a range selected from the group
consisting of: (i) 1.0-1.5 ms; (ii) 1.5-2.0 ms; (iii)
2.0-2.5 ms; (iv) 2.5-3.0 ms; (v) 3.0-3.5 ms; (vi) 3.5-
4.0 ms; (vii) 4.0-4.5 ms; (viii) 4.5-5.0 ms; (ix) 5-10
ms; (x) 10-15 ms; (xi) 25-20 ms; (xii) 20-25 ms; (xiii)
25-30 ms; (xiv) 30-35 ms; (xv) 35-40 ms; (xvi) 40-45 ms;
(xvii) 45-50 ms; (xviii) 50-55 ms; (xix) 55-60 ms; (xx)
60-65 ms; (xxi) 65-70 ms; (xxii) 70-75 ms; (xxiii) 75-80
ms; (xxiv) 80-85 ms; (xxv) 85-90 ms; (xxvi) 90-95 ms;
(xxvii) 95-100 ms; and (xxviii) > 100 ms.
26. A mass spectrometer as claimed in any preceding,
claim, wherein said one or more transient DC voltages
create: (i) a potential hill or barrier; (ii) a
potential well; (iii) a combination of a potential hill
or barrier and a potential well; (iv) multiple potential
hills or barriers; (v) multiple potential wells; or (vi)
a combination of multiple potential hills or barriers
and multiple potential wells.
27. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltage
waveforms comprise a repeating waveform.
28. A mass spectrometer as claimed in claim 27, wherein
said one or more transient DC voltage waveforms comprise
a square wave.
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29. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltage
waveforms create a plurality of potential peaks or wells
separated by intermediate regions.
30. A mass spectrometer as claimed in claim 29, wherein
the DC voltage gradient in said intermediate regions is
zero or non-zero.
31. A mass spectrometer as claimed in claim 29, wherein
said DC voltage gradient in said intermediate regions is
positive or negative.
32. A mass spectrometer as claimed in claim 29, wherein
the DC voltage gradient in said intermediate regions is
linear.
33. A mass spectrometer as claimed in claims 29,
wherein the DC voltage gradient in said intermediate
regions is non-linear.
34. A mass spectrometer as claimed in claim 33, wherein
said DC voltage gradient in said intermediate regions
increases or decreases exponentially.
35. A mass spectrometer as Claimed in any of claims 29-
34, wherein the amplitude of said potential peaks or
wells remains substantially constant.
36. A mass spectrometer as claimed in any of claims 29-
34, wherein the amplitude of said potential peaks or
wells becomes progressively larger or smaller.
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37. A mass spectrometer as claimed in claim 36, wherein
the amplitude of said potential peaks or wells increases
or decreases either linearly or non-linearly.
38. A mass spectrometer as claimed in any preceding
claim, wherein in use an axial DC voltage gradient is
maintained along at least a portion of the length of
said mass filter and wherein said axial voltage gradient
varies with time.
39. A mass spectrometer as claimed in any preceding
claim, wherein said mass filter comprises a first
electrode held at a first reference potential, a second
electrode held at a second reference potential, and a
third electrode held at a third reference potential,
wherein:
at a first time t1 a first DC voltage is supplied
to said first electrode so that said first electrode is
held at a first potential above or below said first
reference potential;
at a second later time t2 a second DC voltage is
supplied to said second electrode so that said second
electrode is held at a second potential above or below
said second reference potential; and
at a third later time t3 a third DC voltage is
supplied to said third electrode so that said third
electrode is held at a third potential above or below
said third reference potential.
40. A mass spectrometer as claimed in claim 39,
wherein:
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at said first time t1 said second electrode is at
said second reference potential and said third electrode
is at said third reference potential;
at said second time t2 said first electrode is at
said first potential and said third electrode is at said
third reference potential; and
at said third time t3 said first electrode is at
said first potential and said second electrode is at
said second potential.
41. A mass spectrometer as claimed in claim 39,
wherein:
at said first time t1 said second electrode is at
said second reference potential and said third electrode
is at said third reference potential;
at said second time t2 said first electrode is no
longer supplied with said first DC voltage so that said
first electrode is returned to said first reference
potential and said third electrode is at said third
reference potential; and
at said third time t3 said first electrode is at
said first reference potential said second electrode is
no longer supplied with said second DC voltage so that
said second electrode is returned to said second
reference potential.
42. A mass spectrometer as claimed in any of claims 39-
41, wherein said first, second and third reference
potentials are substantially the same.
43. A mass spectrometer as claimed in any of claims 39-
41, wherein said first, second and third DC voltages are
substantially the same.
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44. A mass spectrometer as claimed in any of claims 39-
43, wherein said first, second and third potentials are
substantially the same.
45. A mass spectrometer as claimed in any preceding
claim, wherein said mass filter comprises 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 25, 26, 27, 28, 29, 30 or >30
segments, wherein each segment comprises 1, 2, 3, 4, 5,
6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or >30 electrodes
and wherein the electrodes in a segment are maintained
at substantially the same DC potential.
46. A mass spectrometer as claimed in claim 45, wherein
a plurality of segments are maintained at substantially
the same DC potential.
47. A mass spectrometer as claimed in claim 45 or 46,
wherein each segment is maintained at substantially the
same DC potential as the subsequent nth segment wherein
n is 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30
or >30.
48. A mass spectrometer as claimed in any preceding
claim, wherein ions are radially confined within said
mass filter in a pseudo-potential well and are moved
axially by a real potential barrier or well.
49. A mass spectrometer as claimed in any preceding
claim, wherein in use one or more AC or RF voltage
waveforms are applied to at least some of said
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electrodes so that ions are urged along at least a
portion of the length of said mass filter.
50. A mass spectrometer as claimed in any preceding
claim, wherein the transit time of ions through said
mass filter is selected from the group consisting of:
(i) less than or equal to 20 ms; (ii) less than or equal
to 10 ms; (iii) less than or equal to 5 ms; (iv) less
than or equal to 1 ms; and (v) less than or equal to 0.5
ms.
51. A mass spectrometer as claimed in any preceding
claim, wherein said mass filter is maintained, in use,
at a pressure such that substantially no viscous drag is
imposed upon ions passing through said mass filter.
52. A mass spectrometer as claimed in any preceding
claim, wherein, in use, the mean free path of ions
passing through said mass filter is greater than the
length of said mass filter.
53. A mass spectrometer as claimed in any preceding
claim, wherein in use said one or more transient DC
voltages or said one or more transient DC voltage
waveforms are initially provided at a first axial
position and are then subsequently provided at second,
then third different axial positions along said mass
filter.
54. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms move
from one end of said mass filter to another end of said
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mass filter so that at least some ions are urged along
said mass filter.
55. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC Voltages or
said one or more transient DC voltage waveforms have at
least 2, 3, 4, 5, 6, 7, 8, 9 or 10 different amplitudes.
56. A mass spectrometer as claimed in any preceding
claim, wherein the amplitude of said one or more
transient DC voltages or said one or more transient DC
voltage waveforms remains substantially constant with
time.
57. A mass spectrometer as claimed in any of claims 1-
55, wherein the amplitude of said one or more transient
DC voltages or said one or more transient DC voltage
waveforms varies with time.
58. A mass spectrometer as claimed in claim 57, wherein
the amplitude of said one or more transient DC voltages
or said one or more transient DC voltage waveforms
either: (i) increases with time; (ii) increases then
decreases with time; (iii) decreases with time; or (iv)
decreases then increases with time.
59. A mass spectrometer as claimed in any preceding
claim, wherein said mass filter comprises an upstream
entrance region, a downstream exit region and an
intermediate region, wherein:
in said entrance region the amplitude of said one
or more transient DC voltages or said one or more
transient DC voltage waveforms has a first amplitude;
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in said intermediate region the amplitude of said
one or more transient DC voltages or said one or more
transient DC voltage waveforms has a second amplitude;
and
in said exit region the amplitude of said one or
more transient DC voltages or said one or more transient
DC voltage waveforms has a third amplitude.
60. A mass spectrometer as claimed in claim 59, wherein
the entrance and/or exit region comprise a proportion of
the total axial length of said mass filter selected from
the group consisting of: (i) < 5%; (ii) 5-10%; (iii) 10-
15%; (iv) 15-20%; (v) 20-25%; (vi) 25-30%; (vii) 30-35%;
(viii) 35-40%; and (ix) 40-45%.
61. A mass spectrometer as claimed in claim 59 or 60,
wherein said first and/or third amplitudes are
substantially zero and said second amplitude is
substantially non-zero.
62. A mass spectrometer as claimed in claim 59, 60 or
61, wherein said second amplitude is larger than said
first amplitude and/or said second amplitude is larger
than said third amplitude.
63. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms pass in
use along said mass filter with a first velocity.
64. A mass spectrometer as claimed in claim 63, wherein
said first velocity: (i) remains substantially constant;
(ii) varies; (iii) increases; (iv) increases then
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decreases; (v) decreases; (vi) decreases then increases;
(vii) reduces to substantially zero; (viii) reverses
direction; or (ix) reduces to substantially zero and
then reverses direction.
65. A mass spectrometer as claimed in claim 63 or 64,
wherein said one or more transient DC voltages or said
one or more transient DC voltage waveforms causes some
ions within said mass filter to pass along said mass
filter with a second different velocity.
66. A mass spectrometer as claimed in claim 53, 64 or
65, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms causes
at least some ions within said mass filter to pass along
said mass filter with a third different velocity.
67. A mass spectrometer as claimed in any of claims 63-
66, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms causes
at least some ions within said mass filter to pass along
said mass filter with a fourth different velocity.
68. A mass spectrometer as claimed in any of claims 63-
67, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms causes
at least some ions within said mass filter to pass along
said mass filter with a fifth different velocity.
69. A mass spectrometer as claimed in any of claims 63-
68, wherein said second and/or said third and/or said
fourth and/or said fifth velocity is at least 1, 5, 10,
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15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80,
85, 90, 95 or 100 m/s faster than said first velocity.
70. A mass spectrometer as claimed in any of claims 63-
68, wherein said second and/or said third and/or said
fourth and/or said fifth velocity is at least 1, 5, 10,
15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80,
85, 90, 95 or 100 m/s slower than said first velocity.
71. A mass spectrometer as claimed in any of claims 63-
70, wherein said first velocity is selected from the
group consisting of: (i) 10-250 m/s; (ii) 250-500 m/s;
(iii) 500-750 m/s; (iv) 750-1000 m/s; (v) 1000-1250 m/s;
(vi) 1250-1500 m/s; (vii) 1500-1750 m/s; (viii) 1750-
2000 m/s; (ix) 2000-2250 m/s; (x) 2250-2500 m/s; (xi)
2500-2750 m/s; (xii) 2750-3000 m/s; (xiii) 3000-3250
m/s; (xiv) 3250-3500 m/s; (xv) 3500-3750 m/s; (xvi)
3750-4000 m/s; (xvii) 4000-4250 m/s; (xviii) 4250-4500
m/s; (xix) 4500-4750 m/s; (xx) 4750=5000 m/s; (xxi)
5000-5250 m/s; (xxii) 5250-5500 m/s; (xxiii) 5500-5750
m/s; (xxiv) 5750-6000 m/s; and (xxv) > 6000 m/s.
72. A mass spectrometer as claimed in claim 63-71,
wherein said second and/or said third and/or said fourth
and/or said fifth velocity are selected from the group
consisting of: (i) 10-250 m/s; (ii) 250-500 m/s; (iii)
500-750 m/s; (iv) 750-1000 m/s; (v) 1000-1250 m/s; (vi)
1250-1500 m/s; (vii) 1500-1750 m/s; (viii) 1750-2000
m/s; (ix) 2000-2250 m/s; (x) 2250-2500 m/s; (xi) 2500-
2750 m/s; (xii) 2750-3000 m/s; (xiii) 3000-3250 m/s;
(xiv) 3250-3500 m/s; (xv) 3500-3750 m/s; (xvi) 3750-4000
m/s; (xvii) 4000-4250 m/s; (xviii) 4250-4500 m/s; (xix)
4500-4750 m/s; (xx) 4750-5000 m/s; (xxi) 5000-5250 m/s;
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(xxii) 5250-5500 m/s; (xxiii) 5500-5750 m/s; (xxiv)
5750-6000 m/s; and (xxv) > 6000 m/s.
73. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms has a
frequency, and wherein said frequency: (i) remains
substantially constant; (ii) varies; (iii) increases;
(iv) increases then decreases; (v) decreases; or (vi)
decreases then increases.
74. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms has a
wavelength, and wherein said wavelength: (i) remains
substantially constant; (ii) varies; (iii) increases;
(iv) increases then decreases; (v) decreases; or (vi)
decreases then increases.
75. A mass spectrometer as claimed in any preceding
claim, wherein two or more transient DC voltages or two
or more transient DC voltage waveforms pass
simultaneously along said mass filter.
76. A mass spectrometer as claimed in claim 75, wherein
said two or more transient DC voltages or said two or
more transient DC voltage waveforms are arranged to
move: (i) in the same direction; (ii) in opposite
directions; (iii) towards each other; or (iv) away from
each other.
77. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltages or
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said one or more transient DC voltage waveforms passes
along said mass filter and at least one substantially
stationary transient DC potential voltage or voltage
waveform is provided at a position along said mass
filter.
78. A mass spectrometer as claimed in any preceding
claim, wherein said one or more transient DC voltages or
said one or more transient DC voltage waveforms are
repeatedly generated and passed in use along said mass
filter, and wherein the frequency of generating said one
or more transient DC voltages or said one or more
transient DC voltage waveforms (i) remains
substantially constant; (ii) varies; (iii) increases;
(iv) increases then decreases; (v) decreases; or (vi)
decreases then increases.
79. A mass spectrometer as claimed in any preceding
claim, wherein in use a continuous beam of ions is
received at an entrance to said mass filter.
80. A mass spectrometer as claimed in any of claims 1-
78, wherein in use packets of ions are received at an
entrance to said mass filter.
81. A mass spectrometer as claimed in any preceding
claim, wherein in use pulses of ions emerge from an exit
of said mass filter.
82. A mass spectrometer as claimed in claim 81, further
comprising an ion detector, said ion detector being
arranged to be substantially phase locked in use with
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the pulses of ions emerging from the exit of the mass
filter.
83. A mass spectrometer as claimed in claim 81 or 82,
further comprising a Time of Flight mass analyser
comprising an electrode for injecting ions into a drift
region, said electrode being arranged to be energised in
use in a substantially synchronised manner with the
pulses of ions emerging from the exit of the mass
filter.
84. A mass spectrometer as claimed in any preceding
claim, wherein said mass filter is selected from the
group consisting of: (i) an ion funnel comprising a
plurality of electrodes having apertures therein through
which ions are transmitted in use, wherein the diameter
of said apertures becomes progressively smaller or
larger; (ii) an ion tunnel comprising a plurality of
electrodes having apertures therein through which ions
are transmitted in use, wherein the diameter of said
apertures remains substantially constant; and (iii) a
stack of plate, ring or wire loop electrodes.
85. A mass spectrometer as claimed in any preceding
claim, wherein said mass filter comprises a plurality of
electrodes, each electrode having an aperture through
which ions are transmitted in use.
86. A mass spectrometer as claimed in any preceding
claim, wherein each electrode has a substantially
circular aperture.
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87. A mass spectrometer as claimed in any preceding
claim, wherein each electrode has a single aperture
through which ions are transmitted in use.
88. A mass spectrometer as claimed in Claim 85, 86 or
87, wherein the diameter of the apertures of at least
10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95% of
the electrodes forming said mass filter is selected from
the group Consisting of: (i) less than or equal to 10
mm; (ii) less than or equal to 9 mm; (iii) less than or
equal to 8 mm; (iv) less than or equal to 7 mm; (v) less
than or equal to o mm; (vi) less than or equal to 5 mm;
(vii) less than or equal to 4 mm; (viii) less than or
equal to 3 mm; (ix) less than or equal to 2 mm; and (x)
less than or equal to 1 mm.
89. A mass spectrometer as claimed in any preceding
Claim, wherein at least 10%, 20%, 30%, 40%, 50%, 60%,
70%, 80%, 90% or 95% of the electrodes forming the mass
filter have apertures which are substantially the same
size or area.
90. A mass spectrometer as claimed in any of Claims 1-
83, wherein said mass filter comprises a segmented rod
set.
91. A mass spectrometer as Claimed in any preceding
Claim, wherein said mass filter consists of: (i) 10-20
electrodes; (ii) 20-30 electrodes; (iii) 30-40
electrodes; (iv) 40-50 electrodes; (v) 50-60 electrodes;
(vi) 60-70 electrodes; (vii) 70-80 electrodes; (viii)
80-90 electrodes; (ix) 90-100 electrodes; (x) 100-110
electrodes; (xi) 110-120 electrodes; (xii) 120-130
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electrodes; (xiii) 130-140 electrodes; (xiv) 140-150
electrodes; (xv) more than 150 electrodes; or (xvi) >= 15
electrodes.
92. A mass spectrometer as claimed in any preceding
claim, wherein the thickness of at least 10%, 20%, 30%,
40%, 50%, 60%, 70%, 80%, 90% or 95% of said electrodes
is selected from the group consisting of: (i) less than
or equal to 3 mm; (ii) less than or equal to 2.5 mm;
(iii) less than or equal to 2.0 mm; (iv) less than or
equal to 1.5 mm; (v) less than or equal to 1.0 mm; and
(vi) less than or equal to 0.5 mm.
93. A mass spectrometer as claimed in any preceding
claim, wherein said mass filter has a length selected
from the group consisting of: (i) less than 5 cm; (ii)
5-10 cm; (iii) 10-15 cm; (iv) 15-20 cm; (v) 20-25 cm;
(vi) 25-30 cm; and (vii) greater than 30 cm.
94. A mass spectrometer as claimed in any preceding
claim, wherein at least 10,%, 20,%, 30,%, 40,%, 50%, 60,%,
70%, 80%, 90%, or 95% of said electrodes are connected
to both a DC and an AC or RF voltage supply.
95. A mass spectrometer as claimed .in any preceding
claim, wherein axially adjacent electrodes are supplied
with AC or RF voltages having a phase difference of
180°.
96. A mass spectrometer as claimed in any preceding
claim, further comprising an ion source selected from
the group consisting of a (i) Electrospray ("ESI") ion
source; (ii) Atmospheric Pressure Chemical Ionisation
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("APCI") ion source; (iii) Atmospheric Pressure Photo
Ionisation ("APPI") ion source; (iv) Matrix Assisted
Laser Desorption Ionisation ("MALDI") ion source; (v)
Laser Desorption Ionisation ("LDI") ion source; (vi)
Inductively Coupled Plasma ("ICP") ion source; (vii)
Electron Impact ("EI) ion source; (viii) Chemical
Ionisation ("CI") ion source; (ix) a Fast Atom
Bombardment ("FAB") ion source; and (x) a Liquid
Secondary Ions Mass Spectrometry ("LSIMS") ion source.
97. A mass spectrometer as claimed in any of claims 1-
96, further comprising a continuous ion source.
98. A mass spectrometer as claimed in any of claims 1-
96, further comprising a pulsed ion source.
99. A mass filter for separating ions according to
their mass to charge ratio, said mass filter comprising
at least seven electrodes wherein, in use, an AC or RF
voltage is applied to said electrodes in order to
radially confine ions within said mass filter and
wherein in use one or more transient DC voltages or one
or more transient DC voltage waveforms are progressively
applied to said electrodes so that at least some ions
having a first mass to charge ratio are separated from
other ions having a second different mass to charge
ratio which remain substantially radially confined
within said mass filter.
100. A mass filter for separating ions according to
their mass to charge ratio, said mass filter comprising
at least seven electrodes wherein, in use, an AC or RF
voltage is applied to said electrodes in order to
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radially confine ions within said mass filter and
wherein in use one or more transient DC voltages or one
or more transient DC voltage waveforms are progressively
applied to said electrodes so that ions are moved
towards a region of the mass filter wherein at least one
electrode has a potential such that at least some ions
having a first mass to charge ratio will pass across
said potential whereas other ions having a second
different mass to charge ratio will not pass across said
potential but will remain substantially radially
confined within said mass filter.
101. A mass filter for separating ions according to
their mass to charge ratio, said mass filter comprising
a plurality of electrodes wherein, in use, an AC or RF
voltage is applied to said electrodes in order to
radially confine ions within said mass filter and
wherein in use one or more transient DC voltages or one
or more transient DC voltage waveforms are progressively
applied to said electrodes so that:
(i) ions are moved towards a region of the mass
filter wherein at least one electrode has a first
potential such that at least some ions having first and
second different mass to charge ratios will pass across
said first potential whereas other ions having a third
different mass to charge ratio will not pass across said
first potential; and then
(ii) ions having said first and second mass to
charge ratios are moved towards a region of the mass
filter wherein at least one electrode has a second
potential such that at least some ions having said first
mass to charge ratio will pass across said second
potential whereas other ions having said second
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different mass to charge ratio will not pass across said
second potential.
102. A method of mass spectrometry comprising:
receiving ions in a mass filter comprising at least
seven electrodes wherein an AC or RF voltage is applied
to said electrodes in order to radially confine ions
within said mass filter; and
progressively applying to said electrodes one or
more transient DC voltages or one or mare transient DC
voltage waveforms so that at least some ions having a
first mass to charge ratio are separated from other ions
having a second different mass to charge ratio which
remain substantially radially confined within said mass
filter.
103. A method of mass spectrometry comprising:
receiving ions in a mass filter comprising at least
seven electrodes wherein an AC or RF voltage is applied
to said electrodes in order to radially confine ions
within said mass filter; and
progressively applying to said electrodes one or
more transient DC voltages or one or more transient DC
voltage waveforms so that ions are moved towards a
region of the mass filter wherein at least one electrode
has a potential such that at least some ions having a
first mass to charge ratio will pass across said
potential whereas other ions having a second different
mass to charge ratio will not pass across said potential
but will remain substantially radially confined within
said mass filter.
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104. A method of mass spectrometry comprising:
receiving ions in a mass filter comprising a
plurality of electrodes wherein an AC or RF voltage is
applied to said electrodes in order to radially confine
ions within said mass filter;
progressively applying to said electrodes one or
more transient DC voltages or one or more transient DC
voltage waveforms sa that ions are moved towards a
region of the mass filter wherein at least one electrode
has a first potential such that at least some ions
having a first and second different mass to charge
ratios will pass across said first potential whereas
other ions having a third different mass to charge ratio
will not pass across said first potential; and then
progressively applying to said electrodes one or
more transient DC voltages or one or more transient DC
voltage waveforms so that ions having said first and
second mass to charge ratios are moved towards a region
of the mass filter wherein at least one electrode has a
second potential such that at least some ions having
said first mass to charge ratio will pass across said
second potential whereas other ions having said second
different mass to charge ratio will not pass across said
second potential.
105. A method of mass to charge ratio separation
comprising:
receiving ions in a mass filter comprising at least
seven, electrodes wherein an AC or RF voltage is applied
to said electrodes in order to radially confine ions
within said mass filter; and
progressively applying to said electrodes one or
more transient DC voltages or one or more transient DC
-63-
voltage waveforms so that at least some ions having a
first mass to charge ratio are separated from other ions
having a second different mass to charge ratio which
remain substantially radially confined within said mass
filter.
106. A method of mass to charge ratio separation
comprising:
receiving ions in a mass filter comprising at least
seven electrodes wherein an AC or RF voltage is applied
to said electrodes in order to radially confine ions
within said mass filter; and
progressively applying to said electrodes one or
more transient DC voltages or one or more transient DC
voltage waveforms so that ions are moved towards a
region of the mass filter wherein at least one electrode
has a potential such that at least some ions having a
first mass to charge ratio will pass across said
potential whereas other ions having a second different
mass to charge ratio will not pass across said potential
but will remain substantially radially confined within
said mass filter:
107. A method of mass to charge ratio separation
comprising:
receiving ions in a mass filter comprising a
plurality of electrodes wherein an AC or RF voltage is
applied to said electrodes in order to radially confine
ions within said mass filter;
progressively applying to said electrodes one or
more transient DC voltages or one or more transient DC
voltage waveforms so that ions are moved towards a
region of the mass filter wherein at least one electrode
-64-
has a first potential such that at least some ions
having a first and second different mass to charge
ratios will pass across said first potential whereas
other ions having a third different mass to charge ratio
will not pass across said first potential; and then
progressively applying to said electrodes one or
more transient DC voltages or one or more transient DC
voltage waveforms so that ions having said first and
second mass to charge ratios are moved towards a region
of the mass filter wherein at least one electrode has a
second potential such that at least some ions having
said first mass to charge ratio will pass across said
second potential whereas other ions having said second
different mass to charge ratio will not pass across said
second potential.
108. A mass filter wherein ions separate within said
mass filter according to their mass to charge ratio and
assume different essentially static or equilibrium axial
positions along the length of said mass filter.
109. A mass filter as claimed in claim 108, wherein said
mass filter comprises a plurality of electrodes wherein,
in use, an AC or RF voltage is applied to said
electrodes in order to radially confine ions within said
mass filter.
110. A mass filter as claimed in claim 109, wherein one
or more transient DC voltages or one or more transient
DC voltage waveforms are progressively applied to said
electrodes so as to urge at least some ions in a first
direction.
-65-
111. A mass filter as claimed in claim 110, wherein a DC
voltage gradient acts to urge at least some ions in a
second direction, said second direction being opposed to
said first direction.
112. A mass filter as claimed in claim 110 or 111,
wherein the peak amplitude of said one or more transient
DC voltages or said one or more transient DC voltage
waveforms remains substantially constant or reduces
along the length of the mass filter.
113. A mass filter as claimed in claim 111 or 112,
wherein said DC Voltage gradient progressively increases
along the length of the mass filter.
114. A mass filter as claimed in any of claims 108-113,
wherein once ions have assumed essentially static or
equilibrium axial positions along the length of said
mass. filter at least some of said ions are then arranged
to be moved towards an exit of said mass filter.
115. A mass filter as claimed in claim 114, wherein at
least some of said ions are arranged to be moved towards
an exit of said mass filter by: (i) reducing or
increasing an axial DC Voltage gradient; (ii) reducing
or increasing the peak amplitude of one or more
transient DC voltages or one or more transient DC
voltage waveforms; (iii) reducing or increasing the
velocity of one or more transient DC Voltages or one or
more transient DC voltage waveforms; or (iv) reducing or
increasing the pressure within said mass filter.
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116. A mass spectrometer comprising a mass filter as
claimed in any of claims 108-115.
117. A method of mass to charge ratio separation
comprising causing ions to separate within a mass filter
and assume different essentially static or equilibrium
axial positions along the length of the mass filter.
118. A method of mass to charge ratio separation as
claimed in claim 117, wherein said mass filter comprises
a plurality of electrodes wherein, in use, an AC or RF
voltage is applied to said electrodes in order to
radially confine ions within said mass filter.
119. A method of mass to charge ratio separation as
claimed in claim 118, wherein one or more transient DC
voltages or one or more transient DC voltage waveforms
are progressively applied to said electrodes so as to
urge at least some ions in a first direction.
120. A method of mass to charge ratio separation as
claimed in claim 119, wherein a DC voltage gradient acts
to urge at least some ions in a second direction, said
second direction being opposed to said first direction.
121. A method of mass to charge ratio separation as
claimed in claim 119 or 120, wherein the peak amplitude
of said one or more transient DC voltages or said one or
more transient DC voltage waveforms remains
substantially constant or reduces along the length of
the mass filter.
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122. A method of mass to charge ratio separation as
claimed in claim 120 or 121, wherein said DC voltage
gradient progressively increases along the length of the
mass filter.
123. A method of mass to charge ratio separation as
claimed in any of claims 117-122, wherein once ions have
assumed essentially static or equilibrium axial
positions along the length of said mass filter at least
some of said ions are then arranged to be moved towards
an exit of said mass filter.
124. A method of mass to charge ratio separation as
claimed in claim 123, wherein at least some of said ions
are arranged to be moved towards an exit of said mass
filter by: (i) reducing or increasing an axial DC
voltage gradient; (ii) reducing or increasing the peak
amplitude of one or more transient DC voltages or one or
more transient DC voltage waveforms; (iii) reducing or
increasing the velocity of one or more transient DC
voltages or one or more transient DC voltage waveforms;
or (iv) reducing or increasing the pressure within said
mass filter.
125. A method of mass spectrometry comprising any of the
methods of mass to charge ratio separation as claimed in
claims 117-124.
