Transcript ICP-MS SHORT COURSE TOPICS: 1. GENERAL ANALYTICAL CAPABILITIES 2. ICP AS ION SOURCE 3.

ICP-MS SHORT COURSE
1
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 & VACUUM CONSIDERATIONS
7. MATRIX EFFECTS
8. SOLVENT REMOVAL & COLLISION CELLS
QUESTIONS WELCOME ANYTIME!!!
2
GENERAL ICP-MS REFS.
HANDBOOK OF ICP-MS
JARVIS, GRAY AND HOUK, 1992
VIRIDIAN PUBL., [email protected]
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.
HOUK, ACCOUNTS CHEM. RESEARCH, 1994, 27, 333.
3
ICP LISTSERVER
Send e-mail message to Mike Cheatham at
[email protected]
Include line:
SUBSCRIBE
[email protected]
4
5
IONIZATION IN ICP
H
He
0 .1
M+/(M+ + M) (%)
L i Be
B
C
75
58
5
0 .1
0 .1
9e -4
6e -6
Na M g
A l
S i
P
S
C l
Ar
98
85
Se
Br
Kr
33
5
0 .6
I
Xe
29
8 .5
100
100
K
100
Rb
100
Cs
100
98
Ca
Sc
Ti
V
100
99
99
Y
Zr
98
99
La
Hf
99 ,1
Sr
96 ,4
Ba
91 ,9 90 ,10
Fr Ra
96
C r M n Fe
98
Nb M o
98
94
96
Tc R u
98
Ta W
95
95
Co
93
Zn
91
90
75
Rh Pd
Ag
93
P t Au
Hg
96
94
Re O s
Ir
93
N i Cu
78
93
62
51
33
G a G e As
98
90
Cd
n
I
Sn
85
99
38
N
96
T l Pb
52
O
14
S b Te
78
66
B i
Po
F
0 .9
Ne
0 .04
A t Rn
100 97 ,0 .01 92
Ac
Ce
%M+2
P r N d Pm
96 ,2 90 ,10
99 *
Th
U
100 *
T = 7500 K
Pa
Sm
E u G d Tb
97 ,3 100 * 93 ,7
Np
P u Am
Cm
100 *
ne = 1 x 1015 cm-3
*These elements also make M+2
99 *
Bk
D y Ho
100 *
Cf
E r Tm
Yb
99 *
92 ,8
E s Fm
91 ,9
M d No
Lu
Lw
ION SAMPLING INTERFACE
6
ION
LENS
SAMPLER
SKIMMER
7
AGILENT 7500
LOAD
COIL
TORCH
SAMPLER
SPRAY
CHAMBER
SKIMMER
8
ICP-MS DEVICE
9
ANALYTE SPECTRA 10 ppb Ce
50X
m/z =
136, 138
Ce+
106 c/s
m/z =
140, 142
Ce+2
~104 c/s
CeO+
~104 c/s
Mass to charge ratio
CeOH+
10
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
11
INTERFERENCES (REL. TO ICP-AES)
SPECTRAL
OVERLAP
LESS FREQUENT
LESS SEVERE
MORE PREDICTABLE
EASIER TO CORRECT
MATRIX
INTS.
WORSE IN
ICP-MS
- PLUGGING
- CHANGE OF SIGNAL
(usually loss)
12
13
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. CONSTANT
TMAH (Me4N+OH-) IN H2O
BIO. MATERIALS
14
MICROWAVE SAMPLE DISSOLUTION
SEALED VESSELS
OK FOR VOLATILE
ELEMENTS
POWER REGULATED
SAFETY VALVES
15
ACIDS NEEDED TO PeKEEP
ELEMENTS
IN
SOLUTION
rio d ic Ta b le o f t he Ele m e nt s
1A
1
8A
18
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
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
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 )
55
Cs
133
56
Ba
137
57
La
139
72
Hf
178
73
Ta
181
74
W
184
75
Re
186
87
Fr
(2 2 3 )
88
Ra
226
89
Ac
227
HF
8B
Lant ha nide s
59
Pr
141
Act inide s
90
Th
232
91
Pa
231
60
Nd
144
92
U
238
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
14
Si
2 8 .1
15
P
3 1 .0
16
S
3 2 .1
17
Cl
3 5 .4
10
Ne
2 0 .2
18
Ar
3 9 .9
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
52
Te
128
53
I
127
54
Xe
131
10
1B
11
2B
12
27
Co
5 8 .9
28
Ni
5 8 .7
29
Cu
6 3 .5
30
Zn
6 5 .4
13
Al
2 7 .0
31
Ga
6 9 .7
44
Ru
101
45
Rh
103
46
Pd
106
47
Ag
108
48
Cd
112
49
In
115
50
Sn
119
51
Sb
122
76
Os
190
77
Ir
192
78
Pt
195
79
Au
197
80
Hg
201
81
Tl
204
82
Pb
207
83
Bi
209
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 )
58
Ce
140
3A
13
85
86
84
At
Rn
Po
(2
1
0
)
(
2
22)
(2 0 9 )
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
169 173
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 )
16
LOW BLANKS?
NALGENE OR POLYETHYLENE
OK FOR DIW
TEFLON 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
Elemental Scientific Inc.
MicroFlow PFA Nebulizer
• 100% Teflon
• Self-aspiration:
–
–
–
–
20 µL/min
50 µL/min
100 µL/min
400 µL/min
17
Na 0 to 5 ppt Calibration
PFA-20 with HP4500
18
19
20
S. JET & SKIMMING PROCESS
ICP
T ~ 5000 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
21
Sampler
Skimmer
Photo by A. L. Gray
22
ION LENS
23
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
24
0 volts
25
EINZEL LENS
INITIAL KE
=200 eV
230 eV
FOCAL POSITION
VARIES WITH
INITIAL ION KE
26
AGILENT 7500 OMEGA LENS
Model of Ion Mirror Optics
28
27
VARIAN ICP-MS
28
29
30
QUADRUPOLE MASS ANALYZER
y
x
U + V cos wt
- (U + V cos wt)
Thermo Elemental
31
POTENTIAL = F (x,y,t) = (U + V cos w t)(x2 - y2)/r02
MATHIEU EQUATIONS
a = 4zU/mw 2r02
f = w t/2
q = 2zV/ mw 2r02
+ rods d2x/df 2 + (a + 2q cos 2f) x = 0
- rods d2y/df 2 - (a + 2q cos 2f) x = 0
d2z/ df 2 = 0
32
FILTERING ACTION
Positive Rods
M + heavier ions
M + lighter ions
Negative Rods
33
SIMION - QUADRUPOLE
10 Ions
All m/z = 100
m/z = 100 STABLE
10 Ions
All m/z = 90
10 Ions
All m/z = 110
34
35
STABILITY DIAGRAM
UNSTABLE PATHS
a = 4U/(m/z)r02w2
q = 2V/(m/z)r02w2
a
q
STABILITY DIAGRAM & SCAN LINE
SCAN LINE
U/V = const
M
M-1
a
a = 4U/(m/z)r02w2
M+1
q = 2V/(m/z)r02w2
q
36
37
PEAK SHAPE, RESOLUTION & ABUNDANCE SENSITIVITY
RESOLUTION a U/V RATIO
LOW
RESOLUTION
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)
ELECTRON MULTIPLIER
-2800 V
38
ANALOG
OUT, GATE
GAIN ~ 106
+
-3000 V
PULSE
COUNTING
OUTPUT
GAIN ~ 108
39
40
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.
41
ESA
42
Detector
Entrance
slit
Magnet
& flight
tube
ELEMENT
SCANNING HIGH RES
ICP-MS DEVICE
Quad lenses
Extraction lenses
Skimmer
Sampler
ICP
Neb &
Spray chamber
43
10 ppb Zn
PFA 100
64Zn+
66Zn+
68Zn+
67Zn+
70Zn+
44
PEAK SHAPES
LOW & HIGH RES.
Spectra
Photoresist Interferences on Cu
12C H +
5 3
12CH 32S16O+
3
63Cu+
45
46
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
47
MASS DISPERSION
320
280
240
200
7 ions start m/z = 200
D m/z = 20
48
BEAM BROADENING
BY SPREAD OF
KINETIC ENERGY
7 ions m/z = 200
KE = 2000 eV
D KE = 10 eV
49
FOCUSING EFFECT
IONS INJECTED OVER
VARIOUS ANGLES
7 ions m/z = 200
D injection angle = 1o
50
FINNIGAN ELEMENT DEMO
DOUBLE FOCUSING:
SIMULTANEOUS ANGULAR &
ENERGY FOCUSING
51
Fig. 17. NU Plasma
multicollector instrument
with zoom lens and multiple
electron multiplier detectors.
Figure provided by NU Plasma.
52
NIST 610 glass Pb isotopes
40 mm spot MICROMASS ISOPROBE
spot
207Pb/206Pb
1
0.91757
0.02
2
0.91747
3
%1se
208Pb/204Pb
%1se
2.20277
0.01
38.54770
0.03
0.01
2.20253
0.01
38.58310
0.03
0.91741
0.02
2.20265
0.01
38.56520
0.03
4
0.91723
0.02
2.20216
0.01
38.58606
0.02
5
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
53
54
MATRIX EFFECTS
55
SOLIDS DEPOSITION IN ICP-MS
Douglas & Kerr, JAAS 1988, 3, 744
56
MATRIX EFFECT
Olivares & Houk, Anal. Chem 1986, 58, 20.
57
VARIATION OF SIGNAL & MATRIX EFFECT
WITH NEB. GAS FLOW Tan & Horlick JAAS 1987, 2, 745.
YO, Y(I), Y(II) EMISSION ZONES
COURTESY VARIAN
58
59
60
61
Gillson, Tanner, Douglas
62
Co+
Trajectories
80% Ar+
20% O+
80% Ar+
19% O+
1% U+
63
INTERNAL STANDARD
Co+
Standard Additions
Ca Calibration in 38% HF (w/w)
64
PFA-100, PFA
endcap, Pt
injector
Cool plasma
conditions
Tamapure HF
Grade AA10
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
65
66
ISOTOPE DILUTION
Beauchemin et al., Anal. Chem. 1987, 59, 610.
67
REMOVE POLYATOMIC IONS?
ALTER ICP:
COOL PLASMA
SOLVENT REMOVAL
REMOVE/SEPARATE POLY. IONS
FROM M+ ANALYTE IONS:
HIGH RESOLUTION
COLLISION CELLS
68
S+
IE
(eV)
10.36
BAD
GUYS
O2+
IE
(eV)
12.063
D0 69
(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
SO
GOOD
GUYS/GALS
+
12.34
SOLVENT REMOVAL
REDUCE MO+
ANALYSIS OF ORGANIC
SOLVENTS
IMPROVE SENSITIVITY,
ESP. FOR SECTOR
INSTRUMENTS (?)
70
Elemental Scientific Inc.
MicroFlow PFA Nebulizer
• 100% Teflon
• Self-aspiration:
–
–
–
–
20 µL/min
50 µL/min
100 µL/min
400 µL/min
71
SPRAY CHAMBER & SOLVENT REMOVAL
72
Aerosol out
Coolant
Drain
Fig. 21. Cooled spray chambers for solvent removal. a) cooled double pass
Scott chamber b) Cyclone chamber, side and top views. In both chambers,
most of the large droplets are deposited at the bends, while fine droplets pass out
to the plasma.
73
Comparison of desolvation methods
JAAS 1998, 13, 167-174.
74
75
Elemental Scientific Inc.
Apex
Heated Cyclonic SC
(120C/140C)
Peltier-Cooled
Multipass Condenser
2C/-5C
Total Internal Volume 180 ml
76
50 ppq Ce
Apex + Element
77
COLLISION CELLS
78
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 M+ IONS
79
MULTIPOLE COLLISION CELLS
FOR REMOVING POLYATOMIC IONS
IN ICP-MS
GV PLATFORM (QUADRUPOLE)
ISOPROBE
PE SCIEX DYNAMIC REACTION CELL
THERMO X
AGILENT 7500cs
S+
IE
(eV)
10.36
BAD
GUYS
O2+
IE
(eV)
12.063
D0 80
(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
SO
GOOD
GUYS/GALS
+
12.34
ICP PLATFORM, MICROMASS LTD.
HEX BIAS
= -2.0 VOLTS
QUAD BIAS
= + 2.0 VOLTS
81
82
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
Hex Bias -2.2, IE = 1.0, Mult = 482, H2 = 0 ml/min
10
MICROMASS PLATFORM
83
84
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
QUAD POLE BIAS (volts)
5
85
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
86
87
REACTION PROFILES
1e7
1e6
1e5
m/z = 80
1 ppb Se
1e4
1000
m/z = 78
1 ppb Se
100
m/z = 82
1 ppb Se
m/z = 78
10
m/z = 80
1
0.05 0.15
0.25
0.35 0.45 0.55 0.65 0.75
CH4 FLOW RATE (L/min)
0.85 0.95
88
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
Infinity
TM
Lens
- High Efficiency
Ion Guide
89
90
AGILENT 7500cs OCTOPOLE COLLISION CELL
91
KINETIC ENERGY DISCRIMINATION
600
NO COLL. GAS
Analyte
Interferent
500
400
N 300
200
100
KE
2
1.
6
1.
2
0.
8
0.
4
0
0
92
POLY. ION HAS LARGER CROSS SECTION
FOR KE LOSS
600
Analyte
Interferent
500
POTENTIAL BARRIER
STOPS POLY. IONS
400
N
300
200
100
KE
2
1.
6
1.
2
0.
8
0.
4
0
0
1 ppb V, Cr, Mn, Ni, Co, Cu, Zn, As
500 ppm each C, Na, S, Cl, Ca
93
COLLISION REACTION INTERFACE
VARIAN, KALINITCHENKO et al.
94
SKIMMER
+ 74 mL/min H2
or 110 mL/min He
ICP
SAMPLER
95
96
Seronorm Urine 2525
97
ACKNOWLEDGMENTS
TRANSGENOMIC CETAC
ELEMENTAL SCIENTIFIC
THERMO FINNIGAN
GV (MICROMASS)
PE SCIEX
LECO
THERMO ELEMENTAL
AGILENT VARIAN
98