INTRO TO ICP-MS
1
R. S. HOUK
AMES LABORATORY - USDOE, IOWA STATE UNIV.
TOPICS:
1. GENERAL ANALYTICAL CAPABILITIES
2. ICP AS ION SOURCE
3. SAMPLE PREP & SAMPLE INTRO
4. ION EXTRACTION, TRANSMISSION
AND FOCUSING
5. MASS ANALYSIS – QUADRUPOLE, MAGNETIC SECTOR
6. ION DETECTION
7. MATRIX EFFECTS
8. APPLICATIONS SURVEY
9.
SOLVENT REMOVAL, COOL PLASMA & COLLISION CELLS
QUESTIONS WELCOME ANYTIME!!!
GENERAL ICP-MS REFS.
2
HANDBOOK OF ICP-MS
JARVIS, GRAY AND HOUK, 1992
VIRIDIAN PUBL., viridian.tc@virgin.net
ICPs IN ANAL. ATOMIC SPECTROMETRY
ICPMS
MONTASER, ED., VCH, NEW YORK, 1992 & 1998
ICP MS HANDBOOK
NELMS, ED. BLACKWELL/CRC, 2005
DEAN, PRACTICAL ICP SPECTROSCOPY, WILEY-VCH,
2005.
BECKER, INORGANIC MS: PRINCIPLES &
APPLICATIONS, WILEY, 2008
1
ICP LISTSERVER
3
Send e-mail message to Mike Cheatham at
mmcheath@mailbox.syr.edu
Include line:
SUBSCRIBE
PLASMACHEM-L@LISTSERV.SYR.EDU
COURSE NOTES AT: houk.public.iastate.edu
EXPERIENCE WITH:
ICP-MS?
ICP-AES?
OTHER MS?
NEITHER?
4
PART I. OVERALL ANALYTICAL PROCESS
Analyst Client
DEFINE
PROBLEM
SELECT
METHOD
SAMPLING
SAMPLE
PREP.
EVALUATE
DATA
MEAS.
ANALYTES
2
5
ICP AS ION SOURCE
NORMAL ANALYTICAL ZONE (blue)
INITIAL RAD. ZONE (red)
INDUCTION REGION
LOAD
COIL
TORCH
OUTER GAS FLOW
AEROSOL GAS FLOW INTO AXIAL CHANNEL
6
AGILENT 7500
LOAD
COIL
TORCH
SAMPLER
SPRAY
CHAMBER
SKIMMER
3
7
Y+
YO
Y NEUTRAL
AT SPOT USUALLY USED IN ICP-MS:
8
Just off tip of initial radiation zone
Tgas = 6000 K
ntotal = P/RTgas = 1.5 x 1018 cm-3
mostly Ar
ne = n+ = 1 x 1015 cm-3
Flow velocity ~ 25 m/s
Residence time ~ 2 ms
4
DISSOCIATION
9
MO+ Ö M+ + O
Kd = (nM+ nO)/nMO+
∆H = D0 (MO+)
log K d (cm -3 ) = 1.5 log Tgas -
M + Mo
5040 D 0
+ 1.5 log M
Tgas
M MO +
+
M
z elec
z Oelec
+ log
+ 20.274
Z′MO +
nM+ / nMO+ INCREASES AS:
D0 <
Tgas >
nO <
IONIZATION SAHA EQUATION
M Ö M+ + e-
10
Kion = nM ne/nM
∆H = IE (M)
+
log K ion (cm -3 ) = 1.5 log Tion -
5040 IE
Tion
+
M
z elec
+ log M + 15.684
z elec
SIMILAR RELATIONSHIP FOR
M+ Ö M2+ + e-
5
11
ION SAMPLING INTERFACE
12
ION
LENS
SAMPLER
SKIMMER
6
13
ICP-MS DEVICE
14
ION COUNT RATE
1 ppb Ce
Thermo X2
m/z RATIO
7
15
ICP-MS CAPABILITIES
DETECTION LIMITS
0.1 - 10 ppt routine
10 ppq SOME INSTS.
USUALLY BLANK-LIMITED
TOTAL SOLUTES
0.1% USUALLY OK
1% USUALLY PROBLEMS
UNLESS USE FLOW INJECTION
PRECISION
3% RSD ROUTINE
1% GOOD
1% ROUTINE W. INT. STDS.
ACCURACY COMPARABLE TO PRECISION IF
COMPENSATE FOR INTERFERENCES
INTERFERENCES (REL. TO ICP-AES)
16
SPECTRAL
OVERLAP
LESS FREQUENT THAN AES
LESS SEVERE
MORE PREDICTABLE
EASIER TO CORRECT
MATRIX
INTS.
WORSE IN
ICP-MS
- PLUGGING
- CHANGE OF SIGNAL
(usually loss)
8
APPLICATION AREAS
17
1. ENVIRONMENTAL ANALYSIS
STANDARD REGULATORY METHODS
RESEARCH
2. GEOCHEMISTRY
RARE EARTHS
PROSPECTING, Pt GROUP ELEMENTS
U-Th-Pb DATING
LASER ABLATION
3. SEMICONDUCTORS
DIW, MINERAL ACIDS
ORGANIC SOLVENTS
SURFACE LAYERS, VAPOR-PHASE DECOMP..
18
APPLICATION AREAS
4. NUCLEAR INDUSTRY
RADIONUCLIDES
PURITY OF MATERIALS
5. BIOMEDICAL
FLUIDS & TISSUES
METALS IN PROTEINS & ENZYMES
6. FORENSICS
MATCHING EVIDENCE BASED
ON TRACE ELEMENT COMPOSITION
9
19
20
SAMPLE DISSOLUTION
DIGEST SOLID?
HNO3 ONLY IF POSSIBLE
HF, H2O2, HClO4 IF NECESSARY
SAFETY!!
APPROVED PROCEDURES
MAKE UP IN AQUEOUS HNO3
TYP. 0.1% SOLUTE IN 1% ACID
KEEP ACID CONC. APPROX. CONSTANT
TMAH (Me4N+OH-) IN H2O
BIO. FLUIDS
10
21
MICROWAVE SAMPLE DISSOLUTION
SEALED VESSELS
OK FOR VOLATILE
ELEMENTS
POWER REGULATED
SAFETY VALVES
ACIDS NEEDED TO KEEP ELEMENTS IN SOLUTION
22
Pe rio d ic Ta ble o f t he Ele m e nt s
8A
18
1A
1
3A
13
4A
14
5A
15
6A
16
7A
17
2
He
4 .0 0
5
B
1 0 .8
6
C
1 2 .0
7
N
1 4 .0
8
O
1 6 .0
9
F
1 9 .0
10
Ne
2 0 .2
2B
12
13
Al
2 7 .0
14
Si
2 8 .1
15
P
3 1 .0
16
S
3 2 .1
17
Cl
3 5 .4
18
Ar
3 9 .9
29
Cu
6 3 .5
30
Zn
6 5 .4
31
Ga
6 9 .7
32
Ge
7 2 .6
33
As
7 4 .9
34
Se
7 9 .0
35
Br
7 9 .9
36
Kr
8 3 .8
46
Pd
106
47
Ag
108
48
Cd
112
49
In
115
50
Sn
119
51
Sb
122
52
Te
128
53
I
1 27
54
Xe
131
78
Pt
195
79
Au
197
80
Hg
201
81
Tl
204
82
Pb
207
83
Bi
209
1
H
1 .0 1
2A
2
3
Li
6 .9 4
4
Be
9 .0 1
11
Na
2 3 .0
12
Mg
2 4 .3
3B
3
4B
4
5B
5
6B
6
7B
7
8
9
10
1B
11
19
K
3 9 .1
20
Ca
4 0 .1
21
Sc
4 5 .0
22
Ti
4 7 .9
23
V
5 0 .9
24
Cr
5 2 .0
25
Mn
5 4 .9
26
Fe
5 5 .8
27
Co
5 8 .9
28
Ni
5 8 .7
37
Rb
8 5 .5
38
Sr
8 7 .6
39
Y
8 8 .9
40
Zr
9 1 .2
41
Nb
9 2 .9
42
Mo
9 5 .9
43
Tc
(9 8 )
44
Ru
101
45
Rh
103
55
Cs
133
56
Ba
137
57
La
139
72
Hf
178
73
Ta
181
74
W
184
75
Re
186
76
Os
190
77
Ir
192
87
Fr
(2 2 3 )
88
Ra
226
89
Ac
227
HF
8B
104
105
106
107
108
109
Rf
Ha
Unh
Uns
Uno
Une
(2 6 1 ) ( 2 6 2 ) (2 6 3 ) ( 2 6 2 ) (2 6 5 ) (2 6 6 )
Lant ha nid e s
58
Ce
140
59
Pr
141
Act inid e s
90
Th
232
91
Pa
231
60
Nd
144
92
U
238
85
86
84
At
Rn
Po
(2 0 9 ) (2 1 0 ) ( 2 2 2 )
HCl
61
62
63
64
65
66
67
68
69
70
71
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
(1 4 5 ) 1 5 0
152
157
159
162
165
167
169 1 73
175
93
94
95
96
97
98
99
100
101
102
103
Np
Pu
Am
Cm
Bk
Cf
Es
Fm
Md
No
Lr
(2 3 7 ) (2 4 4 ) (2 4 3 ) ( 2 4 7 ) (2 4 7 ) (2 5 1 ) ( 2 5 2 ) (2 5 7 ) (2 5 8 ) (2 5 9 ) (2 6 0 )
11
23
LOW BLANKS?
NALGENE OR POLYETHYLENE
OK FOR DIW
TEFLON (PFA or FEP) CONTAINERS
PREFERRED FOR ACIDIC SAMPLES
ACID-WASH:
10% HNO3 + 5% H2O2 + 5% HF (CAREFUL!!)
WARM OVERNIGHT OR LONGER
RINSE & STORE IN DIW
DUST-FREE ENVIRONMENT
KEEP SAMPLE BOTTLES CAPPED
24
CLEAN ACIDS?
SUB-BOILING DISTILLATION
CLEAN ACID
SEASTAR
(VANCOUVER BC)
TAMAPURE
(JAPAN)
S-B STILL
SAVILLEX
(MINNESOTA)
12
25
CONTAMINATION IN MULTIELEMENT TRACE ANALYSIS
RODUSHKIN, ENGSTROM, BAXTER
ANAL. BIOANAL. CHEM 2010, 396, 365-377.
CLEAN WATER
MILLI-Q, REVERSE OSMOSIS + ION EXCHANGE
ALSO SUB-BOILING DISTILLATION
*NO MAKE-UP → Bi & Sb
PIPET CONC. STDS → TINY AEROSOLS
KEEP WASHED TUBES FULL W. DIW + ACID
PLASTIC TUBING (ESP. PERI PUMP)
RETAINS & THEN RELEASES VARIOUS ELEMENTS,
ESP IF USE HF, OR INCREASE ACID CONC.
PLASTIC AUTOSAMPLER TUBES
26
CLEAN ENOUGH AS SUPPLIED FOR MOST GEOLOGICAL
& ENVIRONMENTAL ANALYSIS
MUST BE CLEANED FOR SUB PPB APPLICATIONS
AFTER CLEANING & CLEAN STORAGE,
CAN STILL RELEASE SOME ELEMENTS (Al, Si,Ti, Zn, Cd, Sn)
IF USED WITH CONC. ACIDS (>5%)
BLANK SUBTRACTION
COMPLICATE INTERNAL STANDARDIZATION
SUBTRACT SIGNALS FROM SOLNS.
OR FROM CONES, TUBING ETC.?
13
LAMINAR FLOW CLEAN BOXES
27
*NOT EXHAUSTED! NOT FOR HAZARDOUS FUMES!
28
14
BURGENER NEBULIZERS
Elemental Scientific Inc.
MicroFlow PFA Nebulizer
29
30
• 100% Teflon
• Self-aspiration:
–
–
–
–
20 µL/min
50 µL/min
100 µL/min
400 µL/min
15
Na 0 to 5 ppt Calibration
PFA-20 with HP4500
SPRAY CHAMBER & SOLVENT REMOVAL
31
32
Aerosol out
Coolant
Drain
16
Schematic of SC-FAST
Analysis System
33
Seamless integration with the E2
software/hardware
34
Hg in 10x diluted seawater CRM
~3 ppt Hg as analyzed
•
16 injections 10 minutes
•
•
•
Matrix load on ICPMS cone reduced 3x vs. conventional sample introduction
Hg Detection Limit 0.2 ppt
Spray chamber?
– Alternate 10x diluted seawater and 5% HCl blank
17
35
Nebulizer Rinse Mode Apex FAST
Fast-Rinsing Apex FAST
36
(after 30 minutes Th introduction)
Apex FAST 2ppb Th Injection
7
Log Th232 Signal
6
5
4
3
~20 ppq Th
2
1
0
0
200
400
Neb gas re-started
600
800
1000
1200
Time (sec)
ESI patent pending
18
37
ION EXTRACTION
38
FUNDAMENTAL ASPECTS OF ION EXTRACTION
IN ICP-MS
HOUK & NIU, SPECTROCHIM. ACTA B 1996, 51, 779.
GAS DYNAMICS OF THE ICP-MS INTERFACE
DOUGLAS & FRENCH, JAAS 1988, 3, 743.
IMPROVED INTERFACE FOR ICP-MS
DOUGLAS & FRENCH, SPECTROCHIM. ACTA B
1986, 41, 197.
ION EXTRACTION IN ICP-MS
OLIVARES & HOUK, ANAL. CHEM. 1985, 57, 2674.
CHAP. IN MONTASER ICP-MS BOOK
RECENT PAPERS BY PAUL FARNSWORTH
BRIGHAM YOUNG UNIV.
19
39
40
SECONDARY DISCHARGE
“PINCH”
Photo by A. L. Gray
20
41
Y+ IONS
INTO SAMPLER
42
SYMPTOMS OF SEC. DISCHARGE
ION KEs > , PEAKS SPLIT
M+2/ M+ >
M+ <
ORIFICE METAL IONS APPEAR
BACKGROUND >
SLIDE OF Y PLASMA, NO PINCH
21
REVERSED LOAD COIL
43
REVERSED LOAD COIL
44
VOLTAGE GRADIENT
ALONG COIL
+
+
INDUCES CHARGE SEPARATION,
POTENTIAL GRADIENT
IN PLASMA
-
22
BALANCED LOAD COILS
COLPITTS OSCILLATOR
45
46
23
INTERLACED LOAD COIL, VARIAN/BRUKER
+HV
47
0
POTENTIAL GRADIENTS
ALONG EACH COIL OFFSET
LOW PLASMA POTENTIAL
0
-HV
48
SHIELDED COIL
± HV
GROUNDED METAL SHIELD
INSERTED BETWEEN
COIL AND TORCH
PREVENTS CAPACTIVE COUPLING
BETWEEN LOAD COIL & PLASMA
24
49
50
S. JET & SKIMMING PROCESS
ICP
T ~ 6000 K
N(v)
Barrel shock
VELOCITY
v (Ar)
N(v)
Skimmer
Collisions
Directed flow
in zone of silence
IN JET
T ~ 150 K
0
+
VELOCITY
25
EXTRACTION PROCESS
Douglas & French JAAS 1988
SAMPLER
ICP:
Tion ~ 7000 K
Tgas ~ 6000 K
51
SKIMMER
AT SKIMMER:
Tion ~ 7000 K
Tgas ~ 155 K
TIME ~ 3 µs
~250 colls with Ar
52
Mach disks
Sampler
Photo by A. L. Gray
26
53
HIGH
PRESSURE
SAMPLER - SKIMMER
SEPARATION
SKIMMER
LOW
PRESSURE
From Pertel, Int. J. Mass Spectrom.
Ion Processes, 1975.
54
Sampler
Skimmer
Photo by A. L. Gray
27
55
COLOR SLIDES OF SAMPLER - SKIMMER REGION
CONDITIONS INSIDE SAMPLER
FLOW THROUGH SAMPLER = G0 = 0.445 n0a0D02
a0 = speed of sound in source = ( kTgas,0/m)1/2
D0 = orifice diam.
n0 ~ P/RTgas
TYPICAL G0 ~ 1021 atoms/s
DEBYE LENGTH = λD = (ε0kTe/e2ne)1/2
λD (cm) = 6.9 (Te/ne)1/2 Te in K ne in cm-3 (NEXT SLIDE)
Te ~ 8000 K ne ~ 1015 cm-3
INSIDE SAMPLER λD ~ 10-4 mm << D0
SO PLASMA REMAINS QUASINEUTRAL
AS FLOWS THROUGH SAMPLER
56
λD
Chen, Intro to Plasma Physics, 1984
28
CONDITIONS INSIDE SKIMMER TIP
57
FLOW THROUGH SKIMMER = G1 = n(xs)v(xs)As
v = velocity ~ (5kT0/2m)1/2
As = area of skimmer
TYPICAL G1 ~ 1 x 1019 atoms/s
~ 1% OF FLOW THROUGH SAMPLER
ALSO GOES THRU SKIMMER
λD (cm) = 6.9 (Te/ne)1/2 ne NOW ~1012 cm-3
INSIDE SKIMMER λD ~ 10-2 mm << Ds
SO PLASMA ALSO REMAINS QUASINEUTRAL
AS FLOWS THROUGH SKIMMER
ALTHOUGH MAY BE SIGNIFICANT SHEATH
INSIDE SKIMMER TIP
58
29
59
IONS IN ARGON FLOW
SAMPLER
SKIMMER
ICP
SHOCK WAVES
IONS ENTRAINED IN Ar FLOW
ACCELERATED TO SAME VELOCITY AS Ar
60
AVG. KE OF Ar = AVG. KE IN ICP = 2.5 kTgas
= 0.5 mArvAr2
ALL IONS (i) ACHIEVE SAME VELOCITY
vi = vAr
KEi
= 0.5 mivi2
IONS OF DIFFERENT MASS
HAVE DIFFERENT KINETIC ENERGIES
30
ION ENERGY MEASUREMENT
STOPPING POTENTIAL ON QUAD
61
62
MAX. ION KE (eV)
ION ENERGY vs m/z
m/z
31
63
FLOATING INTERFACE
64
VOLTAGE ON
SAMPLER
ION SIGNAL
+ 40
+20
+40
+30
+20
+10
0
V ON QUAD OR DIFF. PUMPING APERTURE
32
65
MAG. SECTOR
INTERFACES
66
33
ION LENS
67
Equipotential contours
+
+
V1
V2
V1, V2 NOT DEP. ON m/z UNLESS:
- IE = f (m/z)
-SPATIAL DIST. = f (m/z)
SIMION - EINZEL LENS
0
+110
0 volts
FOCAL POSITION
VARIES WITH
APPLIED VOLTAGE
INITIAL ION KE
= 200 eV
0
+140
68
0 volts
34
69
EINZEL LENS
INITIAL KE
=200 eV
FOCAL POSITION
VARIES WITH
INITIAL ION KE
230 eV
AGILENT/HP / YOKOGAWA LENS
70
QUAD
35
71
AGILENT 7500 OMEGA LENS
72
FOCUSING CURVES
Rh+
U+
NORM. ION SIGNAL
Li+
LENS VOLTAGE
36
PE SCIEX LENS
73
SCAN V ON LENS W. m/z
APPLIED V ~ ION KE
OPERATE AT TOP OF FOCUSING CURVE
FOR EACH m/z DESIRED
Model of Ion Mirror Optics
74
28
37
VARIAN/BRUKER ICP-MS
Hot Plasma Performance
ISOTOPE
9Be
115In
140Ce
232Th
•
•
•
CeO+ / Ce+: 1.4%
Ce++ / Ce+: 0.7%
Ba++ / Ba+: 1.9%
75
76
SENSITIVITY
c/s per ppm
102 x 106
1032
1029
854
RSD ~ 1%
BKG ~ 1 c/s at m/z 5,220,228
31
38
SPACE CHARGE EFFECTS
77
OLIVARES & HOUK, ANAL. CHEM. 1985, 57, 2674.
GILLSON et al, ANAL. CHEM. 1988, 60, 1472.
TANNER, SPECTROCHIM. ACTA B 1992, 47B, 809.
PLASMA SOURCE MASS SPECTROMETRY,
DEVELOPMENTS & APPLICATIONS, Holland & Tanner,
Eds., Royal Society, Cambridge, 1997.
EXPECT SPACE CHARGE PROBLEM WHEN:
78
Imax (µA) > 0.9(z/m)1/2(D/L)2V3/2
Imax is current of major bkg. ions
m/z rel. to 12C = 12
V in volts
FOR ICP-MS
Imax ~ 0.4 µA
Actual Imax ~ 1019 atoms/s (nions/natoms)
~ 1019 (1015/1018) ~ 1.5 mA !!
39
EINZEL LENS – EFFECT OF SPACE CHARGE
79
BEAM
CURRENT
0
1 µA
80
40
OVERALL EFFICIENCY
81
1e3 IONS
THRU SKIMMER
1e5 ATOMS
INTO ICP
1e5 IONS
INTO
SAMPLER
1 ION
TO DETECTOR!
82
41
83
QUADRUPOLE MASS ANALYZER
y
x
+
-
-
U + V cos ωt
Thermo Elemental
+
- (U + V cos ωt)
+
-
+
84
HYPERBOLIC QUADRUPOLE FIELD
42
85
POTENTIAL = Φ (x,y,t) = (U + V cos ω t)(x2 - y2)/r02
MATHIEU EQUATIONS
a = 4zU/mω2 r02
φ = ω t/2
q = 2zV/ mω2 r02
+ rods d2x/dφ2 + (a + 2q cos 2φ) x = 0
- rods d2y/dφ2 - (a + 2q cos 2φ) x = 0
d2z/ dφ2 = 0
86
FILTERING ACTION
Positive Rods
M + heavier ions
M + lighter ions
Negative Rods
43
87
SIMION - QUADRUPOLE
10 Ions
All m/z = 100
m/z = 100 STABLE
10 Ions
All m/z = 90
88
10 Ions
All m/z = 110
44
89
STABILITY DIAGRAM
UNSTABLE PATHS
a = 4U/(m/z)r02ω2
q = 2V/(m/z)r02ω2
a
q
STABILITY DIAGRAM & SCAN LINE
90
SCAN LINE
U/V = const
M
M-1
a
a = 4U/(m/z)r02ω2
M+1
q = 2V/(m/z)r02ω2
q
45
91
PEAK SHAPE, RESOLUTION & ABUNDANCE SENSITIVITY
RESOLUTION
LOW
RESOLUTION
α U/V RATIO
ION SIGNAL
RES. & m/z CONTROLLED
ELECTRONICALLY,
NO MECH. MOVEMENT
MEDIUM RES
HIGH RES
M-1
M
M+1
m/z
ABUNDANCE SENS. = (SIGNAL AT M) / (SIGNAL AT M-1 or M+1)
QUAD CHARACTERISTICS
92
SCAN m/z BY CHANGING U & V, ~ CONST. U/V
m/z LINEAR W. U & V
SCAN, HOP V. FAST, 50 µs
MAX. m/z > AS
r0 <
ω <
RES. NOT STRONGLY DEP. ON SPREAD
OF ION KE IF MAX. KE < 15 eV
OPERATE UP TO ~ 10-3 TORR
λ = mean free path (cm) ≈ 5/P (mtorr)
≈ 5 cm ≈ length of quad
46
93
POLE BIAS, SAME DC VOLTAGE ON ALL 4 RODS
U + V cos ωt + pole bias
M + heavier ions
M + lighter ions
-(U + V cos ωt) + pole bias
POSITIVE POLE BIAS:
SLOWS IONS DOWN INSIDE QUAD, MORE RF CYCLES
BETTER RESOLUTION, SOME SAC. OF TRANSMISSION
94
MASS DISCRIMINATION
(U,V) =
IDEAL VALUES
FOR TRANS. ION
AT DESIRED m/z
FRINGE FIELD:
ACTUAL (U,V)
< (U,V)
FOR STABLE PATH
a~
U
q~V
47
95
RF ONLY AC ONLY RODS
EFFICIENT TRANS.
LITTLE RES.
a
U=0
q
96
RF
ONLY
MASS FILTER
RF
ONLY
48
97
ELECTRON MULTIPLIER
ANALOG
OUT, GATE
GAIN ~ 106
-2800 V
+
PULSE
COUNTING
OUTPUT
GAIN ~ 108
-3000 V
98
PULSE COUNTING
-V AT COLLECTOR
SIGNAL PULSE
FWHM ~ 20 ns
COUNT
NOT
COUNTED
DISCRIMINATOR
THRESHOLD
DARK PULSE
TIME
49
LINEAR DYNAMIC RANGE
99
-V AT COLLECTOR
PULSES PILE UP
AT HIGH COUNT RATES,
> 3 X 106 counts/s
CAL. CURVE DROOPS
USE ANALOG SIGNAL
TIME
100
50
101
ALTERNATE MASS ANALYZERS
MAGNETIC SECTOR
Moens & Jakubowski, Anal. Chem. 1998, 70,
251A-256A.
Douthitt, ICP Inform. Newsletter 1999, 25 (2),
87-120.
Becker & Dietze, Spectrochim. Acta B 1998, 53,
1475-1506.
Houk, Handbook of Elemental Speciation,
R. Cornelis, Ed., Wiley, 2003.
102
51
ESA
103
ELEMENT
SCANNING HIGH RES
ICP-MS DEVICE
Detector
Entrance
slit
Quad lenses
Extraction lenses
Skimmer
Sampler
Magnet
& flight
tube
ICP
Neb &
Spray chamber
104
10 ppb Zn
PFA 100
64Zn+
66Zn+
68Zn+
67Zn+
70Zn+
52
105
PEAK SHAPES
LOW & HIGH RES.
Spectra
106
53
107
Photoresist Interferences on Cu
108
12C H +
5 3
12CH 32S16O+
3
63Cu+
54
109
MAG. SECTOR
INTERFACES
QUADRUPOLE LENS
110
DC ONLY
ENT.
SLIT
CONVERT CIRCULAR
BEAM INTO SLIT SHAPED CROSS SECTION
SKIMMER
55
111
MAGNETIC SECTOR MASS ANALYZER
+ ION MOVING THRU MAGNETIC FIELD STRENGTH B
v
B
Fm
v
Fm
Fm
v
Fm = MAGNETIC FORCE
ALWAYS ACTS PERPENDICULAR TO DIR. OF MOTION
112
EXAMPLE
B = 103 Gauss
V = 2000 volts
m = 100 z = +1 m/z = 100
rm = 64 cm
m
B2 rm2
=
z
2V
SCAN m/z BY SCANNING EITHER:
B (vary mag. field)
V (vary acc. voltage) AND / OR
rm (array detector)
56
113
ELECTROSTATIC ANALYZER
re = radius of ion path V = acc. voltage
V′ = voltage across plates, diam. = d
E = radial electric field = V′/d
Fe = electrostatic force = zE = zV′/d
Uniform circular motion when Fe = zE = mv2/re
(NEXT SLIDE)
KE = 0.5mv2 = zV (acc. voltage)
re = 2V/E = 2Vd/ V′
114
FOCUSING PROPERTIES
(+)
Image
(-)
le′
le″
Object
radius re
angle φe
57
115
FOCUSING EQN. MAGNETIC SECTOR
NORMAL (PERPENDICULAR) ION ENTRY
SOURCE, CENTER OF CURVATURE & IMAGE
ALL ON SAME LINE
B
lm″
lm′
rm
2α
φm
Source
Image
*SELECT lm′, lm″, φm , rm TO PROVIDE
FOCUSED IMAGE?
MASS DISPERSION
116
320
280
240
200
7 ions start m/z = 200
∆ m/z = 20
58
117
BEAM BROADENING
BY SPREAD OF
KINETIC ENERGY
7 ions m/z = 200
KE = 2000 eV
∆ KE = 10 eV
118
FOCUSING EFFECT
IONS INJECTED OVER
VARIOUS ANGLES
7 ions m/z = 200
∆ injection angle = 1o
Finnigan Element Demo
59
119
NU INSTRUMENTS
120
attoM
• ICP Source
– Ionisation of most elements
– Simple sample introduction
• High Resolution Capability
– User-selectable mass resolution
– Optimum transmission for
application
– Unambiguous identification and
quantification of isotopic peaks
• Double Focusing Analyser
– Low ion energy spread
– Low pressure 10-7 mbar
• Fully Laminated Magnet
• FastScan Ion Optics
• Single Collector
60
Variable Resolution
121
100
100
Transmission (%)
(%)
Transmission
90
90
Isotope
Mass
Interferant
Mass
Resolution
27.9769
N2
28.0061
960
31
30.9738
NOH
31.0058
970
32
31.9721
O2
31.9898
1800
80
80
28
70
70
Si
P
S
60
60
39
50
50
38.9637
ArH
38.9706
5700
51
V
50.9440
ClO
50.9638
2600
40
40
56
Fe
55.9349
ArO
55.9573
2500
75
74.9216
ArCl
74.9323
7800
80
79.9165
Ar2
79.9248
9700
K
As
30
30
Se
20
20
10
10
00
00
2000
2000
4000
4000
6000
6000
8000
8000
10000
10000
12000
12000
14000
14000
Resolution
Resolution (R=M/DeltaM)
(R=M/DeltaM)
Resolution can be optimised for specific applications and sensitivity
does not have to be compromised by “over-resolution”.
122
Separation of Analyte from Interfering Species
Separation of
56Fe
56Fe
from ArO
ArO
Flat top peak – Interference-free
analysis of transition elements
Separation of
80Se
80Se
from Ar2
Ar
2
Triangular peak shape but separated peaks
– Sample quantification in complex
matrixes
61
attoM
Scanning Modes
• Magnetic Scanning
–
–
–
–
–
Fast Magnetic Scanning
Slow – 0.1 sec per step
Conventional mass scanning
For small mass ranges
Instrument tuning
High resolution
attoM
123
Fast – m/z 6 to 250 to 6 in <120 ms
“Over-voltage” technique
Magnetic field ramps up or collapses at
a defined rate
Whole mass range to be scanned very
quickly – Up and Down
Ideal for fast quantification of unknown
samples
124
Scanning Modes
Combination of Fast Magnetic
Scanning and FastScan Ion Optics
Optimises analysis
time
62
125
attoM
Scanning Modes
Combination of Static Magnet and
FastScan Ion Optics
User selects masses and software
defines the required magnet positions
and FastScan Optic voltages to analyse
the whole suite
Magnet automatically “parked” at midpoint of the selected mass range
Different voltages are applied onto the
FastScan Optics to measure and jump
between pre-selected isotopes
Peak jumping with ion optics only !
No alteration of acceleration energy !
126
Fig. 17. NU Plasma
multicollector instrument
with zoom lens and multiple
electron multiplier detectors.
Figure provided by NU Plasma.
63
NIST 610 glass Pb isotopes
40 µm spot MICROMASS ISOPROBE
127
spot
207Pb/206Pb
1
0.91757
0.02
2
0.91747
3
0.91741
4
5
%1se
208Pb/204Pb
%1se
2.20277
0.01
38.54770
0.03
0.01
2.20253
0.01
38.58310
0.03
0.02
2.20265
0.01
38.56520
0.03
0.91723
0.02
2.20216
0.01
38.58606
0.02
0.91723
0.02
2.20234
0.01
38.56478
0.04
6
0.91751
0.01
2.18400
0.01
38.30902
0.04
7
0.91761
0.01
2.19877
0.01
38.46679
0.05
8
0.91752
0.02
2.19090
0.02
38.34840
0.03
9
0.91728
0.09
2.20196
0.01
38.57391
0.05
%1se
208Pb/206Pb
mean
0.91743
2.19867
38.50500
1SD
0.00015
0.00670
0.10655
%1SD
0.02
0.30
0.28
SPECTRO MS
MATTAUCH-HERZOG GEOMETRY
WITH MULTICHANNEL DETECTOR
128
QUAD
LENS
ENT SLIT
ESA
SOLID-STATE
ARRAY
DETECTOR
MAGNET
64
ICP-TOF-MS
129
RAY & HIEFTJE, JAAS 2001, 16, 1206-1216.
GUILHAUS et al.
MASS SPECTROM. REVIEWS
2000, 19, 65-107.
GBC OPTIMASS 8000
Orthogonal Acceleration - TOF MS
130
RF Generator
Ion
Reflectron
Gas Control Unit
Peristaltic
Pump
Liner
Impedance
Matching
Network
Gate
Valve
3-cone
Interface
Ion
Optics
Ion
Blanker
Spray
Chamber
Detector
Pre-amp
Collector
Plasma Torch
Orthogonal
Accelerator
Turbo 3
Turbo 2
Turbo 1
Rotary
Vacuum
Pump
65
131
CyTOF
DVS SCIENCES
132
MATRIX EFFECTS
66
133
SOLIDS DEPOSITION IN ICP-MS
Douglas & Kerr, JAAS 1988, 3, 744
1% Na or K
U
Al
Ca
Zr
134
MATRIX EFFECT
Olivares & Houk, Anal. Chem 1986, 58, 20.
67
135
VARIATION OF SIGNAL & MATRIX EFFECT
WITH NEB. GAS FLOW Tan & Horlick JAAS 1987, 2, 745.
YO, Y(I), Y(II) EMISSION ZONES
COURTESY VARIAN
136
68
137
138
69
139
Gillson, Tanner, Douglas
140
Co+
Trajectories
80% Ar+
20% O+
80% Ar+
19% O+
1% U+
70
INTERNAL STANDARD
141
Co+
Standard Additions
Ca Calibration in 38% HF (w/w)
142
PFA-100,
PFA endcap,
Pt injector
Cool plasma
conditions
Tamapure HF
Grade AA10
71
MARINE SEDIMENT REF. MATERIAL BCSS-1, 0.1%
McLaren et al. JAAS 1987
Element
CONCENTRATIONS (µg/g ± std dev, n = 4)
External
Standard
Accepted (info)
Calibration
Addition
Value
V
Mn
Co
Ni
Cu
Zn
71 ± 3
156 ± 8
8.9 ± 0.2
43 ± 1
24 ± 1
124 ± 8
93 ± 16
220 ± 19
13 ± 3
57 ± 6
29 ± 3
123 ± 5
93 ± 5
229 ± 15
11 ± 2
55 ± 4
19 ± 3
119 ± 12
As
Mo
Cd
Pb
14 ± 1
3.0 ± 0.1
0.26 ± 0.02
22 ± 1
12 ± 1
1.8 ± 0.2
0.27 ± 0.03
23 ± 2
11 ± 1
(1.9)
0.25 ± 0.04
23 ± 3
143
144
ISOTOPE DILUTION
Beauchemin et al., Anal. Chem. 1987, 59, 610.
72
145
REMOVE POLYATOMIC IONS?
146
ALTER ICP:
COOL PLASMA
SOLVENT REMOVAL
REMOVE/SEPARATE POLY. IONS
FROM M+ ANALYTE IONS:
HIGH RESOLUTION
COLLISION CELLS
73
GUYS/GALS
S+
IE
(eV)
10.36
BAD
GUYS
O2 +
IE
(eV)
12.063
D0 147
(eV)
6.663
Fe+
7.87
ArO+
ArN+
~ 13
~14
0.312
1.866
Se+
9.75
Ar2+
~15
1.25
K+
4.34
ArH+
~10
4.00*
V+
6.74
ClO+
11.1
4.65
Ti+
6.82
SO+
10.0
5.43
Zn+
9.39
SO2+
12.34
GOOD
SOLVENT REMOVAL
148
REDUCE MO+ (also KE discrimination)
ANALYSIS OF ORGANIC
SOLVENTS
IMPROVE SENSITIVITY,
ESP. FOR SECTOR
INSTRUMENTS (?)
74
Elemental Scientific Inc.
MicroFlow PFA Nebulizer
149
• 100% Teflon
• Self-aspiration:
–
–
–
–
20 µL/min
50 µL/min
100 µL/min
400 µL/min
150
SPRAY CHAMBER & SOLVENT REMOVAL
Aerosol out
Coolant
Drain
75
151
CYCLONE SPRAY CHAMBER
152
Comparison of desolvation methods
JAAS 1998, 13, 167-174.
76
153
154
DESOLVATION SYSTEM FOR MICRONEBULIZER
CETAC ARIDUS
77
155
Elemental Scientific Inc.
Apex
Heated Cyclonic SC
(120C/140C)
Peltier-Cooled
Multipass Condenser
2C/-5C
Total Internal Volume 180 ml
156
50 ppq Ce
Apex + Element
78
Elemental Scientific Inc.
Apex FAST Diagram
157
Apex +158
Spiro
100 ppt
In and Ce
CeO+
CeO+/Ce+
= 0.03%
79
Membrane Reduction of ArCl+
Apex-Spiro Teflon Membrane Desolvator
159
*LARGE SENSITIVITY
ENHANCEMENT FOR As+!
160
80
COOL ICP
161
Jiang, Stevens & Houk, Anal. Chem. 1988, 60, 1217-1221.
Nonose, SAB 1994, 49, 495-526.
Kawabata & Sakata, SAB 1994, 49,
Tanner, JAAS 1995, 10, 905-921.
OPERATE PLASMA COOLER CONDS. & SAMPLE IONS
FROM REGION WHERE NO+, O2+ AND/OR H3O+
ARE MAJOR BACKGROUND IONS
SECONDARY DISCHARGE DUE TO POTENTIAL GRADIENT
COUPLED FROM LOAD COIL INTO PLASMA
DISCHARGE BECOMES MORE INTENSE AS
-AEROSOL GAS FLOW >
-POWER <
-SOLVENT LOAD >
-MOVE SAMPLER FURTHER FROM LOAD COIL
162
SHIELDED COIL
± HV
GROUNDED METAL SHIELD
INSERTED BETWEEN
COIL AND TORCH
PREVENTS CAPACTIVE COUPLING
BETWEEN LOAD COIL & PLASMA
81
163
INTERLACED LOAD COIL, VARIAN/BRUKER
+HV
0
POTENTIAL GRADIENTS
ALONG EACH COIL OFFSET
LOW PLASMA POTENTIAL
0
-HV
COOL PLASMA CHARACTERISTICS
164
TANNER, JAAS 1995, 10, 908
ELAN 6000
HOT
COOL
POWER
1200 W
600
AEROSOL GAS
0.77 L/min
1.08
SAMPLING
POSITION
9.0 mm
9.0
SPRAY
CHAMBER
Room temp
Room temp
82
165
BACKGROUND SPECTRUM HOT PLASMA
10
10
O+
10 9
Ar+
a
ion signal / cps
ArH+
10
8
10
7
10
6
10
5
10
4
Ar2+
ArO+
10 3
10
2
10
1
10 0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
Mass
YO, Y(I), Y(II) EMISSION ZONES
COURTESY VARIAN
166
83
167
ion signal / cps
BACKGROUND SPECTRUM COOL PLASMA
10
8
10
7
H3O+
NO+
O2+
b
10 6
ArH +
10
5
10
4
10
3
10
2
10
1
Ar +
Ar 2+
Fe+ & ArO +
10 0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
Mass
168
84
COLLISION CELLS
169
Rowan & Houk, Appl. Spectrosc. 1989, 43, 976.
Douglas, Canad. J. Spectrosc. 1989, 34, 38.
King & Harrison, Int. J. Mass Spectrom. Ion Processes
1989, 89, 171.
Turner, Speakman et al., Plasma Source MS, Developments
& Applications, Royal Society, 1997, p. 28.
Baranov & Tanner, JAAS 1999, 14, 1133
JASMS 1999, 10, 1083.
USE COLLISION - INDUCED DISSOCIATION (CID)
&/OR CHEMICAL REACTION TO REMOVE POLY. IONS
RETAIN ATOMIC ANALYTE IONS
REDUCE KE & SPREAD OF KE OF POLY IONS
170
MULTIPOLE COLLISION CELLS
FOR REMOVING POLYATOMIC IONS
IN ICP-MS
GV PLATFORM (QUADRUPOLE)
ISOPROBE
PE SCIEX DYNAMIC REACTION CELL
THERMO X2
AGILENT 7700
85
GUYS/GALS
S+
IE
(eV)
10.36
BAD
GUYS
O2 +
IE
(eV)
12.063
D0 171
(eV)
6.663
Fe+
7.87
ArO+
ArN+
~ 13
~14
0.312
1.866
Se+
9.75
Ar2+
~15
1.25
K+
4.34
ArH+
~10
4.00*
V+
6.74
ClO+
11.1
4.65
Ti+
6.82
SO+
10.0
5.43
Zn+
9.39
SO2+
12.34
GOOD
ICP PLATFORM, MICROMASS LTD.
HEX BIAS
= -2.0 VOLTS
172
QUAD BIAS
= + 3.0 VOLTS
86
173
Ion Signal vs. He Gas Flow Rate
3
Li
Ni
Normalized Signal
2.5
In
U
2
1.5
1
0.5
0
0
2
4
6
He Gas Flow Rate (ml/min)
8
10
Hex Bias -2.2, IE = 1.0, Mult = 482, H2 = 0 ml/min
MICROMASS PLATFORM
174
40Ar +
2
87
175
HEXAPOLE BIAS = -2 volts
100
REL. SIGNAL
*POSITIVE STOPPING VOLTAGE ON QUAD
REJECTS MOST POLY. IONS
V+, Sr+
50
ArH3O+
0
1
2
3
4
5
QUAD POLE BIAS (volts)
176
DYNAMIC REACTION CELL (DRC)
mass analyzer
reaction gas in
reaction cell
isobar
analyte
other m/z
ions to mass analysis of
detector transmitted ions
conversion of
reactive ions
ions from
source
88
177
DRC + AFT SIDE VIEW
178
DRC
RODS
QUAD RODS
IN DRC
AFT
ELECTRODE
Vappl ~ 300 volts DC
AFT ELECTRODES
89
179
REACTION PROFILES
1e7
m/z = 80 1 ppb Se
40Ar + + CH → prods
2
4
1e6
1e5
m/z = 80
1 ppb Se
80Se+ + CH → no rxn.
4
1e4
1000
100
m/z = 78 blank
38Ar40Ar+ + CH
4
→ prods
10
m/z = 80 blank
40Ar + + CH → prods
2
4
m/z = 78
1 ppb Se
m/z = 82
1 ppb Se
1
0.05 0.15
0.25
0.35
0.45
0.55
0.65
0.75
0.85
0.95
CH4 FLOW RATE (L/min)
180
DEATH TO
ArCl+
ION SIGNAL
1 ppb As
+ 1000 ppm NaCl
!
1000 ppm NaCl
25 c/s
1 ppb As
750 c/s
DIW
m/z = 75
90
DL and BEC of ELAN DRC
ESI PFA Nebulizer, Y. Kishi & K. Kawabata
Element
Li (7)
Be (9)
B (11)
Na (23)
Mg (24)
Al (27)
K (39)
Ca (40)
Ti (48)
V (51)
Cr (52)
Mn (55)
Fe (56)
Ni (60)
Co (59)
Cu (63)
Zn (64)
Ga (69)
DL
0.26
1.00
3.60
0.20
0.23
0.23
0.27
0.27
0.92
0.12
0.14
0.17
0.49
0.43
0.04
0.06
0.63
0.06
BEC
0.22
0.87
7.10
0.22
0.18
0.42
2.60
0.63
1.70
0.04
0.29
0.54
2.60
0.66
0.04
0.68
1.20
0.05
Element
Ge (74)
As (75)
Sr (88)
Zr (90)
Mo (98)
Ag (107)
Cd (114)
In (115)
Sn (120)
Sb (121)
Ba (138)
Ta (181)
W (184)
Au (197)
Tl (205)
Pb (208)
Bi (209)
U (238)
Brown color: DRC mode
DL
0.58
0.48
0.03
0.05
0.11
0.09
0.08
0.03
0.12
0.08
0.06
0.06
0.07
0.15
0.02
0.07
0.02
0.02
BEC
0.57
1.60
0.02
0.04
0.12
0.10
0.11
0.02
0.88
0.08
0.04
0.05
0.07
0.05
0.01
0.09
0.01
0.01
Unit: ppt Integration time: 1 sec
THERMODYNAMICS OF ION-NEUTRAL RXNS
182
Ar2+ + e- → Ar2
-Int E(Ar2+) ~ 15.76 – 1.25 ~ -14.5 eV
CH4 → CH4+ + e-
IE(CH4) = 12.6
Ar2+ + CH4 → Ar2 + CH4+ ∆H = IE(CH4) – Int E(Ar2) ~ -1.9 eV
EXOTHERMIC RXN USUALLY RAPID, EXTENSIVE
CH4 → CH4+ + e-
IE(CH4) = 12.6
Se+ + e- → Se
-IE(Se) = -9.75
Se+ + CH4 → Se + CH4+
∆H = IE(CH4) – IE(Se) ~ +2.8 eV
ENDOTHERMIC RXN, SLOWER
KEEP COLLISION ENERGY LOW
91
183
a=0
Select cutoff
with q
q = 2V/(m/z)r02ω2
Fe(NH3)n+ CLUSTERS
184
Low q
0.2
Many
Product
Ions
High q
0.8
Precursor &
Product
Ions
Suppressed
92
185
186
93
PE NEXION
PE NEXION
187
188
94
189
KINETIC ENERGY DISCRIMINATION
190
COLL CELL LENGTH L = 10 cm
GAS DENSITY n
ION HAS CROSS SECTION Ω (cm2)
NUMBER OF COLLISIONS = L/λ = L n Ω
λ = mean free path (cm)
EXPECT ~ 5 TO 10 COLLISIONS
POLY ION IS LARGER
LARGER Ω
MORE COLLISIONS IN SAME LENGTH L
95
191
KE LOSSES & KE DISCRIMINATION
Fraction of KE remaining per coll = α ~
2
2
m coll
gas + mion
(m
+ mion )
2
coll gas
4 2 + 562
α~
= 0.88 for coll of Fe+ and ArO+ with He
2
(4 + 56)
SAY Fe+ HAS 5 COLLS
ArO+ HAS 10 COLLS
Fe+ HAS α5 = 0.885 = 0.52 OF INITIAL KE REMAINING
ArO+ HAS α10 = 0.8810 = 0.28 OF INITIAL KE
Covey & Douglas JASMS 1993 p 616
192
KINETIC ENERGY DISCRIMINATION
600
NO COLL. GAS
Analyte
Interferent
500
400
N 300
200
100
2
1.
6
1.
2
0.
8
0.
4
0
0
KE
96
193
POLY. ION HAS LARGER CROSS SECTION
FOR KE LOSS
600
Analyte
Interferent
500
POTENTIAL BARRIER
STOPS POLY. IONS
400
N
300
200
100
2
1.
6
1.
2
0.
8
0.
4
0
0
KE
194
AGILENT 7500cs OCTOPOLE COLLISION CELL
97
195
AGILENT 7500 cs (now 7700)
OMEGA
LENS
196
98
Acid Matrices & IPA in NoGas Mode
197
(HNO3 + HCl + H2SO4 + IPA)
2E5
cps
Unspiked 5% HNO3 + 5% HCl + 1% H2SO4 + 1% IPA Matrix
Unspiked Matrix – ALL peaks are due to polyatomic interferences
Multiple polyatomic interferences affect almost every
mass – Interferences are matrix-dependent
What happens to all these polyatomics in He Mode?
NoGas Mode
Single Acid Matrices and IPA in He Mode
(HNO3 + HCl + H2SO4 + IPA)
198
Unspiked 5% HNO3 + 5% HCl + 1% H2SO4 + 1% IPA Matrix
2E5
cps
ALL polyatomic interferences are removed in He Mode (same cell conditions)
All polyatomic interferences are removed in He Mode
He Mode
99
AGILENT 8800
199
200
Thermo X Series 2 w CCT
Discrete
Dynode
Detector
Chicane
deflector D1&
2
Exit Lens L3
Pi Lens L1
&2
Xt or Xs
interface
Quadrupole
Mass Filter
Focus
Lens
Hexapole
Collision Cell
Extraction
Lens
100
Single Gas and Flow Rate
Removes Various Poly Ions
100000
1
100000
1
ClO
51V Unspiked
51V Spiked
BEC
10
0.001
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10
10
1000
1
100
0.001
10
1
10
1
2.5 3
3.5 4
4.5 5
5.5 6
6.5 7
0.01
63Cu Spiked
BEC
NaAr
1
B EC (p p b )
BEC (ppb)
0.1
100
Sig n al In te ns ity (icp s)
1
10
75As Unspiked
75As Spiked
BEC
7.5 863Cu
8.5 Unspiked
9 9.5 10
1000
100
0.1
S ign a l In te ns ity (ic ps )
1.5 2
He Gas Flow (ml/min)
60Ni Unpiked
60Ni Spiked
BEC
10000
0.01
0 0.5 1
CaO
0.0001
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10
He Gas Flow (ml/min)
10000
1000
0.01
100
0.1
100000
Log Signal Intensity (icps)
0.1
CaO,
CaOH
1000
10
He Flow Rate (ml/min)
10000
BEC (ppb)
0.01
1
100
10000
Signal Intensity (icps)
100
100000
B EC (ppb)
0.1
10000
1000
ArCl
1
B E C (p pb )
ClO,
ClOH,
ArC
1000
Signal Intensity (ic ps)
59Co Unspiked
59Co Spiked
BEC
BEC (ppb)
Log Signal Intensity (icps)
52Cr Unpiked
52Cr Spiked
BEC
10000
201
100
0.1
10
10
10
1
1
0.001
0
0.5 1
1.5
2
2.5
3
3.5
4
4.5 5
5.5
6
6.5
7
He Gas Flow (ml/min)
7.5
8
8.5
9
9.5 10
0.01
0 0.5 1
1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5
7 7.5 8 8.5 9 9.5 10
He Gas Flow (ml/min)
1
0.01
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10
He Gas Flow (ml/min)
All interferences removed under 1 simple set of conditions!
Cell gas flow optimisations performed in 1:10 diluted seawater
Interference Removal - ICSA
202
Shows measured concentrations for 6020A ICSA solution in standard mode
(without interference correction) and He cell mode
101
He KED Mode for REEs
203
• Rocks
– 100s ppm Ba and 10s ppm Ce
– Low ppb of REEs
• REE distribution
– provides information about
rock formation and origin
– Chondrite plots
• REE ints:
– BaO, BaOH, CeO, CeOH
• He KED Mode
– dramatically reduces MO+
and MOH+
Typical standard ICP-MS
CeO+/Ce+ Ratio ~1-3%
He KED Mode ~ 0.02%
204
COLLISION REACTION INTERFACE
VARIAN/BRUKER
SKIMMER
KALINITCHENKO et al.
+ 74 mL/min H2
or 110 mL/min He
ICP
SAMPLER
102
205
206
103
Seronorm Urine 2525
ACKNOWLEDGMENTS
207
208
CETAC
ELEMENTAL SCIENTIFIC
THERMO FINNIGAN
GV (MICROMASS)
PE SCIEX/SCIEX
LECO
AGILENT
VARIAN/BRUKER
SPECTRO
104
IONIZATION IN ICP
209
H
He
0.1
M+/(M+
+ M) (%)
Li
Be
B
C
N
O
F
Ne
100
75
58
5
0.1
0.1
9e-4
6e-6
Na
Mg
Al
Si
100
98
98
85
33
14
0.9
Ga Ge
As
Se
Br
Kr
33
5
0.6
I
Xe
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
100
99,1
100
99
99
98
95
96
93
91
90
75
Rb
Sr
Y
Zr
Nb Mo
Tc
Ru
Rh Pd
Ag
100
96,4
98
99
98
98
96
94
93
93
Cs
Ba
La
Hf
Ta
W
Re Os
Ir
Pt
96
95
94
93
78
Ce
Pr
100
91,9 90,10
Fr
Ra
S
Cl
Ar
0.04
98
90
52
Cd
In
Sn
Te
99
96
Sb
85
78
66
29
8.5
Au
Hg
Tl
Pb
Bi
Po
At
Rn
62
51
38
Nd Pm
Sm Eu
Gd
Tb
Dy Ho
Er Tm
Yb
Lu
99*
97,3 100*
93,7
99*
100*
99*
91,9
92,8
Pu Am Cm
Bk
Cf
Fm Md
No
100 97,0.01 92
Ac
96,2 90,10
%M+2
P
Th
100*
T = 7500 K
Pa
U
Np
Es
Lw
100*
ne = 1 x 1015 cm-3
*These elements also make M+2
105