1

1INTRO TO ICP-MS

R. S. HOUKAMES LABORATORY - USDOE, IOWA STATE UNIV.

TOPICS:1. GENERAL ANALYTICAL CAPABILITIES2. ICP AS ION SOURCE3. SAMPLE PREP & SAMPLE INTRO4. ION EXTRACTION, TRANSMISSION

AND FOCUSING5. MASS ANALYSIS – QUADRUPOLE, MAGNETIC SECTOR6. ION DETECTION7. MATRIX EFFECTS8. APPLICATIONS SURVEY9. SOLVENT REMOVAL, COOL PLASMA & COLLISION CELLS

QUESTIONS WELCOME ANYTIME!!!

2GENERAL ICP-MS REFS.

HANDBOOK OF ICP-MSJARVIS, GRAY AND HOUK, 1992VIRIDIAN PUBL., viridian.tc@virgin.net

ICPs IN ANAL. ATOMIC SPECTROMETRYICPMSMONTASER, ED., VCH, NEW YORK, 1992 & 1998

ICP MS HANDBOOKNELMS, ED. BLACKWELL/CRC, 2005

DEAN, PRACTICAL ICP SPECTROSCOPY, WILEY-VCH, 2005.

BECKER, INORGANIC MS: PRINCIPLES & APPLICATIONS, WILEY, 2008

2

3ICP LISTSERVER

Send e-mail message to Mike Cheatham atmmcheath@mailbox.syr.eduInclude 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

DEFINEPROBLEM

SELECTMETHOD

SAMPLINGSAMPLE

PREP.

MEAS.ANALYTES

EVALUATEDATA

Analyst Client

3

5ICP AS ION SOURCE

NORMAL ANALYTICAL ZONE (blue )

INITIAL RAD. ZONE (red)

INDUCTION REGION

OUTER GAS FLOW

AEROSOL GAS FLOW INTO AXIAL CHANNEL

LOADCOIL

TORCH

6

SPRAYCHAMBER

TORCH

LOADCOIL

SAMPLER

SKIMMER

AGILENT 7500

4

7

YOY NEUTRAL

Y+

8AT SPOT USUALLY USED IN ICP-MS:

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

5

9DISSOCIATION

MO+ ÖÖÖÖ M+ + O Kd = (nM+ nO)/nMO+

∆∆∆∆H = D0 (MO+)

20.274 Z

z z log

M

M M log 1.5

T

D 5040 - T log 1.5 )(cm K log

MO

Oelec

Melec

MO

oM

gas

0gas

3-d

+′

+

+=

+

+

+

+

nM+ / nMO+ INCREASES AS:D0 <Tgas >nO <

10IONIZATION SAHA EQUATION

M ÖÖÖÖ M+ + e- K ion = nM + ne/nM

∆∆∆∆H = IE (M)

15.684 z

z log

T

IE 5040 - T log 1.5 )(cm K log

Melec

Melec

ionion

3-ion

++

=

+

SIMILAR RELATIONSHIP FORM+ÖÖÖÖ M 2+ + e-

6

11

12

SAMPLER SKIMMER

IONLENS

ION SAMPLING INTERFACE

7

13ICP-MS DEVICE

141 ppb CeThermo X2

m/z RATIO

ION

CO

UN

T R

AT

E

8

15ICP-MS CAPABILITIES

DETECTION LIMITS 0.1 - 10 ppt routine10 ppq SOME INSTS.USUALLY BLANK-LIMITED

TOTAL SOLUTES 0.1% USUALLY OK1% USUALLY PROBLEMSUNLESS USE FLOW INJECTION

PRECISION 3% RSD ROUTINE1% GOOD1% ROUTINE W. INT. STDS.

ACCURACY COMPARABLE TO PRECISION IFCOMPENSATE FOR INTERFERENCES

16INTERFERENCES (REL. TO ICP-AES)

SPECTRAL LESS FREQUENT THAN AESOVERLAP LESS SEVERE

MORE PREDICTABLEEASIER TO CORRECT

MATRIX WORSE ININTS. ICP-MS

- PLUGGING- CHANGE OF SIGNAL(usually loss)

9

17APPLICATION AREAS

1. ENVIRONMENTAL ANALYSISSTANDARD REGULATORY METHODSRESEARCH

2. GEOCHEMISTRYRARE EARTHSPROSPECTING, Pt GROUP ELEMENTSU-Th-Pb DATINGLASER ABLATION

3. SEMICONDUCTORSDIW, MINERAL ACIDSORGANIC SOLVENTSSURFACE LAYERS, VAPOR-PHASE DECOMP..

18

APPLICATION AREAS

4. NUCLEAR INDUSTRYRADIONUCLIDESPURITY OF MATERIALS

5. BIOMEDICALFLUIDS & TISSUESMETALS IN PROTEINS & ENZYMES

6. FORENSICSMATCHING EVIDENCE BASED ON TRACE ELEMENT COMPOSITION

10

19

20

SAMPLE DISSOLUTION

DIGEST SOLID?HNO3 ONLY IF POSSIBLEHF, H2O2, HClO4 IF NECESSARY

SAFETY!!APPROVED PROCEDURES

MAKE UP IN AQUEOUS HNO3TYP. 0.1% SOLUTE IN 1% ACIDKEEP ACID CONC. APPROX. CONSTANT

TMAH (Me 4N+OH-) IN H2OBIO. FLUIDS

11

21

MICROWAVE SAMPLE DISSOLUTION

SEALED VESSELSOK FOR VOLATILEELEMENTS

POWER REGULATED

SAFETY VALVES

22

Periodic Table of t he Eleme nt s

1 0 3Lr

(2 6 0 )

1 0 2No

(2 5 9 )

1 0 1Md

(2 5 8 )

1 0 0Fm

(2 5 7 )

99Es

(2 52 )

9 8Cf

(2 5 1 )

9 7Bk

(2 4 7 )

9 6Cm

(2 4 7 )

9 5Am

(2 4 3 )

9 4Pu

(2 4 4 )

9 3Np

(2 3 7 )

9 2U

2 3 8

9 1Pa

2 3 1

90Th

2 3 2

7 1Lu

1 7 5

7 0Yb

1 73

69Tm1 6 9

6 8Er

1 6 7

67Ho

1 65

6 6Dy

1 6 2

6 5Tb

1 5 9

6 4Gd

1 5 7

6 3Eu

1 5 2

6 2Sm1 5 0

6 1Pm

(1 4 5 )

6 0Nd

1 4 4

5 9Pr

1 41

58Ce

1 4 0

8 A1 8

7 A1 7

6 A1 6

5 A1 5

4 A1 4

3 A1 3

Lant hanides

Act inides

1 0 9Une

(2 6 6 )

1 0 8Uno

(2 6 5 )

1 0 7Uns

(2 6 2 )

1 0 6Unh

(2 6 3 )

1 05Ha

(2 62 )

1 0 4Rf

(2 6 1 )

8 9Ac

2 2 7

8 8Ra

2 2 6

8 7Fr

(2 2 3 )

83Bi

2 0 9

82Pb

2 07

8 1Tl

2 0 4

8 0Hg

2 0 1

7 9Au

1 9 7

7 8Pt

1 9 5

7 7Ir

1 9 2

7 6Os

1 9 0

7 5Re

1 8 6

7 4W

1 8 4

73Ta

1 81

7 2Hf

1 7 8

5 7La

1 3 9

5 6Ba

1 3 7

5 5Cs

1 3 3

51Sb

1 2 2

5 0Sn

1 1 9

4 9In

1 1 5

4 8Cd

1 1 2

4 7Ag

1 0 8

4 6Pd

1 0 6

4 5Rh

1 0 3

4 4Ru

1 0 1

4 3Tc

(9 8 )

4 2Mo

9 5 .9

4 1Nb

9 2 .9

4 0Zr

9 1 .2

3 9Y

8 8 .9

38Sr

8 7 .6

3 7Rb

85 .5

8 6Rn

(2 22 )

85At

(2 1 0 )

8 4Po

(2 0 9 )

5 2Te

1 2 8

5 3I

1 27

5 4Xe

1 3 1

3 6Kr

8 3 .8

3 5Br

7 9 .9

3 4Se

7 9 .0

33As

74 .9

32Ge

7 2 .6

3 1Ga

6 9 .7

3 0Zn

6 5 .4

2 9Cu

6 3 .5

2 8Ni

5 8 .7

2 7Co

5 8 .9

2 6Fe

5 5 .8

2 5Mn

5 4 .9

2 4Cr

5 2 .0

23V

50 .9

22Ti

4 7 .9

2 1Sc

4 5 .0

2 0Ca

4 0 .1

1 9K

3 9 .1

1 8Ar

3 9 .9

1 7Cl

3 5 .4

1 6S

3 2 .1

1 5P

3 1 .0

1 4Si

2 8 .1

1 3Al

2 7 .0

2He

4 .0 0

1 0Ne

2 0 .2

9F

1 9 .0

8O

1 6 .0

7N

14 .0

6C

1 2 .0

5B

1 0 .88 B

2 B1 2

1 B1 11 098

7 B7

6 B6

5B5

4 B4

3 B3

1 2Mg

2 4 .3

1 1Na

2 3 .0

4Be

9 .0 1

3Li

6 .9 4

2 A2

1A1

1H

1 .0 1 HF

HCl

ACIDS NEEDED TO KEEP ELEMENTS IN SOLUTION

12

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 LONGERRINSE & STORE IN DIW

DUST-FREE ENVIRONMENTKEEP SAMPLE BOTTLES CAPPED

24

CLEAN ACIDS?SUB-BOILING DISTILLATION

CLEAN ACIDSEASTAR (VANCOUVER BC)

TAMAPURE (JAPAN)

S-B STILLSAVILLEX (MINNESOTA)

13

25

CONTAMINATION IN MULTIELEMENT TRACE ANALYSISRODUSHKIN, ENGSTROM, BAXTERANAL. BIOANAL. CHEM 2010, 396, 365-377.

CLEAN WATERMILLI-Q, REVERSE OSMOSIS + ION EXCHANGEALSO 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.

26PLASTIC AUTOSAMPLER TUBES

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 SUBTRACTIONCOMPLICATE INTERNAL STANDARDIZATION

SUBTRACT SIGNALS FROM SOLNS.OR FROM CONES, TUBING ETC.?

14

27LAMINAR FLOW CLEAN BOXES

*NOT EXHAUSTED! NOT FOR HAZARDOUS FUMES!

28

15

29BURGENER NEBULIZERS

30

Elemental Scientific Inc.MicroFlow PFA Nebulizer

• 100% Teflon

• Self-aspiration:– 20 µL/min

– 50 µL/min

– 100 µL/min

– 400 µL/min

16

31Na 0 to 5 ppt CalibrationPFA-20 with HP4500

32

Aerosol out

CoolantDrain

SPRAY CHAMBER & SOLVENT REMOVAL

17

33

Schematic of SC-FAST Analysis System

Seamless integration with the E2 software/hardware

34

Hg in 10x diluted seawater CRM~3 ppt Hg as analyzed

• 16 injections 10 minutes– Alternate 10x diluted seawater and 5% HCl blank

• Matrix load on ICPMS cone reduced 3x vs. conventional sample introduction• Hg Detection Limit 0.2 ppt• Spray chamber?

18

35

Nebulizer Rinse Mode Apex FAST

36Fast-Rinsing Apex FAST (after 30 minutes Th introduction)

Apex FAST 2ppb Th Injection

0

1

2

3

4

5

6

7

0 200 400 600 800 1000 1200

Time (sec)

Lo

g T

h23

2 S

ign

al

~20 ppq Th

ESI patent pending

Neb gas re-started

19

37

38ION EXTRACTION

FUNDAMENTAL ASPECTS OF ION EXTRACTION IN ICP-MSHOUK & NIU, SPECTROCHIM. ACTA B 1996, 51, 779.

GAS DYNAMICS OF THE ICP-MS INTERFACEDOUGLAS & FRENCH, JAAS 1988, 3, 743.

IMPROVED INTERFACE FOR ICP-MSDOUGLAS & FRENCH, SPECTROCHIM. ACTA B 1986, 41, 197.

ION EXTRACTION IN ICP-MSOLIVARES & HOUK, ANAL. CHEM. 1985, 57 , 2674.

CHAP. IN MONTASER ICP-MS BOOK

RECENT PAPERS BY PAUL FARNSWORTHBRIGHAM YOUNG UNIV.

20

39

40

SECONDARY DISCHARGE“PINCH”

Photo by A. L. Gray

21

41Y+ IONSINTO 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

22

43REVERSED LOAD COIL

44REVERSED LOAD COIL

+ -

- +

VOLTAGE GRADIENTALONG COIL

INDUCES CHARGE SEPARATION,POTENTIAL GRADIENTIN PLASMA

23

45BALANCED LOAD COILS

46COLPITTS OSCILLATOR

24

47INTERLACED LOAD COIL, VARIAN/BRUKER

+HV 0

0 -HV

POTENTIAL GRADIENTSALONG EACH COIL OFFSET

LOW PLASMA POTENTIAL

48

SHIELDED COIL

±±±± HV

GROUNDED METAL SHIELDINSERTED BETWEENCOIL AND TORCHPREVENTS CAPACTIVE COUPLINGBETWEEN LOAD COIL & PLASMA

25

49

50

S. JET & SKIMMING PROCESS

Barrel shock

Skimmer

Directed flowin zone of silence

Collisions

ICPT ~ 6000 K

v (Ar)

IN JETT ~ 150 K

N(v)

N(v)

VELOCITY

VELOCITY

- 0 +

26

51

SAMPLERSKIMMER

ICP:T ion ~ 7000 KTgas~ 6000 K

AT SKIMMER:T ion ~ 7000 KTgas~ 155 KTIME ~ 3 µs~250 colls with Ar

EXTRACTION PROCESSDouglas & French JAAS 1988

52

Photo by A. L. Gray

SamplerMach disks

27

53

SAMPLER - SKIMMERSEPARATION

SKIMMER

HIGHPRESSURE

LOWPRESSURE From Pertel, Int. J. Mass Spectrom.

Ion Processes, 1975.

54

Sampler

Skimmer

Photo by A. L. Gray

28

55COLOR SLIDES OF SAMPLER - SKIMMER REGIONCONDITIONS INSIDE SAMPLER

FLOW THROUGH SAMPLER = G 0 = 0.445 n0a0D02

a0 = speed of sound in source = ( kTgas,0/m)1/2

D0 = orifice diam. n0 ~ P/RTgas

TYPICAL G 0 ~ 1021 atoms/s

DEBYE LENGTH = λλλλD = (εεεε0kT e/e2ne)1/2

λλλλD (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 λλλλD ~ 10-4 mm << D0

SO PLASMA REMAINS QUASINEUTRALAS FLOWS THROUGH SAMPLER

56

λD

Chen, Intro to Plasma Physics, 1984

29

57CONDITIONS INSIDE SKIMMER TIP

FLOW THROUGH SKIMMER = G 1 = n(xs)v(xs)As

v = velocity ~ (5kT0/2m)1/2 As = area of skimmer

TYPICAL G 1 ~ 1 x 1019 atoms/s ~ 1% OF FLOW THROUGH SAMPLER

ALSO GOES THRU SKIMMER λλλλD (cm) = 6.9 (Te/ne)1/2 ne NOW ~1012 cm-3

INSIDE SKIMMER λλλλD ~ 10-2 mm << Ds

SO PLASMA ALSO REMAINS QUASINEUTRALAS FLOWS THROUGH SKIMMERALTHOUGH MAY BE SIGNIFICANT SHEATH INSIDE SKIMMER TIP

58

30

59IONS IN ARGON FLOW

ICP

SAMPLER

SKIMMER

SHOCK WAVES

60IONS ENTRAINED IN Ar FLOWACCELERATED TO SAME VELOCITY AS Ar

AVG. KE OF Ar = AVG. KE IN ICP = 2.5 kT gas

= 0.5 mArvAr2

ALL IONS (i) ACHIEVE SAME VELOCITYvi = vAr

KE i = 0.5 mivi2

IONS OF DIFFERENT MASSHAVE DIFFERENT KINETIC ENERGIES

31

61ION ENERGY MEASUREMENTSTOPPING POTENTIAL ON QUAD

62

ION ENERGY vs m/z

MA

X. I

ON

KE

(eV

)

m/z

32

63

FLOATING INTERFACE

64

ION

SIG

NA

L

V ON QUAD OR DIFF. PUMPING APERTURE+40 +30 +20 +10 0

VOLTAGE ONSAMPLER

+ 40

+20

33

65

MAG. SECTORINTERFACES

66

34

67ION LENS

V1 V2

+

+

V1, V2 NOT DEP. ON m/z UNLESS:

- IE = f (m/z)-SPATIAL DIST. = f (m/z)

Equipotential contours

68SIMION - EINZEL LENS

0 +110 0 volts

0 +140 0 volts

INITIAL ION KE= 200 eV

FOCAL POSITIONVARIES WITHAPPLIED VOLTAGE

35

69

EINZEL LENS

INITIAL KE=200 eV

230 eV

FOCAL POSITIONVARIES WITHINITIAL ION KE

70AGILENT/HP / YOKOGAWA LENS

QUAD

36

71

AGILENT 7500 OMEGA LENS

72

FOCUSING CURVES

LENS VOLTAGE

NO

RM

. IO

N S

IGN

AL

Li + Rh+ U+

37

73PE SCIEX LENS

SCAN V ON LENS W. m/zAPPLIED V ~ ION KEOPERATE AT TOP OF FOCUSING CURVE FOR EACH m/z DESIRED

74

28

Model of Ion Mirror Optics

38

75

VARIAN/BRUKER ICP-MS

76

31

Hot Plasma Performance

• CeO+ / Ce+: 1.4% RSD ~ 1%

• Ce++ / Ce+: 0.7% BKG ~ 1 c/s at m/z 5,220,228

• Ba++ / Ba+: 1.9%

SENSITIVITYISOTOPE c/s per ppm9Be 102 x 106115In 1032140Ce 1029232Th 854

39

77SPACE CHARGE EFFECTS

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.

78EXPECT SPACE CHARGE PROBLEM WHEN:

Imax (µµµµA) > 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 µµµµA

Actual Imax ~ 1019 atoms/s (nions/natoms)

~ 1019 (1015/1018) ~ 1.5 mA !!

40

79EINZEL LENS – EFFECT OF SPACE CHARGE

BEAMCURRENT

0

1 µµµµA

80

41

81OVERALL EFFICIENCY

1e5 ATOMSINTO ICP

1e5 IONSINTO SAMPLER

1e3 IONSTHRU SKIMMER

1 IONTO DETECTOR!

82

42

83

QUADRUPOLE MASS ANALYZER

+

+

- -

+

+

- -

y

x

U + V cosωωωωt

- (U + V cosωωωωt)

Thermo Elemental

84

HYPERBOLIC QUADRUPOLE FIELD

43

85

POTENTIAL = ΦΦΦΦ (x,y,t) = (U + V cosωωωω t)(x2 - y2)/r02

MATHIEU EQUATIONS

a = 4zU/mωωωω2 r02 q = 2zV/ mωωωω2 r0

2

φ φ φ φ = ωωωω t/2

+ rods d2x/dφ2 + (a + 2q cos 2φ) x = 0

- rods d2y/dφ2 - (a + 2q cos 2φ) x = 0

d2z/ dφ2 = 0

86

FILTERING ACTION

M + heavier ions

M + lighter ions

Positive Rods

Negative Rods

44

87

SIMION - QUADRUPOLE

10 IonsAll m/z = 100

88

10 IonsAll m/z = 90

10 IonsAll m/z = 110

m/z = 100 STABLE

45

89STABILITY DIAGRAM

a

a = 4U/(m/z)r02ωωωω2

q = 2V/(m/z)r02ωωωω2

UNSTABLE PATHS

q

90STABILITY DIAGRAM & SCAN LINE

a

q

SCAN LINEU/V = const

M+1

M-1

M

a = 4U/(m/z)r02ωωωω2

q = 2V/(m/z)r02ωωωω2

46

91

PEAK SHAPE, RESOLUTION & ABUNDANCE SENSITIVITY

ABUNDANCE SENS. = (SIGNAL AT M) / (SIGNAL AT M-1 or M+1)

m/z

RESOLUTION α U/V RATIO

RES. & m/z CONTROLLEDELECTRONICALLY , NO MECH. MOVEMENT

ION

SIG

NA

L

M-1 M M+1

LOWRESOLUTION

MEDIUM RES

HIGH RES

92

SCAN m/z BY CHANGING U & V, ~ CONST. U/V

m/z LINEAR W. U & V

SCAN, HOP V. FAST, 50 µµµµs

MAX. m/z > AS r0 < ω ω ω ω <

RES. NOT STRONGLY DEP. ON SPREADOF ION KE IF MAX. KE < 15 eV

OPERATE UP TO ~ 10-3 TORR

λ = λ = λ = λ = mean free path (cm) ≈ ≈ ≈ ≈ 5/P (mtorr) ≈≈≈≈ 5 cm ≈≈≈≈ length of quad

QUAD CHARACTERISTICS

47

93

POLE BIAS, SAME DC VOLTAGE ON ALL 4 RODS

M + heavier ions

M + lighter ions

U + V cosωt + pole bias

-(U + V cosωt) + pole bias

POSITIVE POLE BIAS:SLOWS IONS DOWN INSIDE QUAD, MORE RF CYCLESBETTER RESOLUTION, SOME SAC. OF TRANSMISSION

94

MASS DISCRIMINATION

FRINGE FIELD:ACTUAL (U,V) < (U,V) FOR STABLE PATH

(U,V) = IDEAL VALUESFOR TRANS. ION AT DESIRED m/z

a ~U

q ~ V

48

95RF ONLY AC ONLY RODS

a

qU = 0

EFFICIENT TRANS.LITTLE RES.

96

MASS FILTERRFONLY

RFONLY

49

97ELECTRON MULTIPLIER

+

-3000 V

-2800 V

ANALOGOUT, GATEGAIN ~ 106

PULSECOUNTINGOUTPUTGAIN ~ 108

98PULSE COUNTING

TIME

-V A

T C

OLL

EC

TO

R

DISCRIMINATORTHRESHOLD

COUNT

NOTCOUNTED

FWHM ~ 20 nsSIGNAL PULSE

DARK PULSE

50

99LINEAR DYNAMIC RANGE

TIME

-V A

T C

OL

LE

CT

OR PULSES PILE UP

AT HIGH COUNT RATES,> 3 X 106 counts/sCAL. CURVE DROOPS

USE ANALOG SIGNAL

100

51

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

52

103

Quad lenses

Extraction lensesSkimmer

Sampler

Entranceslit

Magnet& flighttube

ESA

DetectorELEMENTSCANNING HIGH RESICP-MS DEVICE

ICP

Neb &Spray chamber

104

64Zn+

66Zn+

67Zn+

68Zn+

70Zn+

10 ppb ZnPFA 100

53

105

Spectra

PEAK SHAPES LOW & HIGH RES.

106

54

107

108Photoresist Interferences on Cu

12C5H3+

12CH332S16O+

63Cu+

55

109

MAG. SECTORINTERFACES

110QUADRUPOLE LENS

SKIMMER

ENT.SLIT

CONVERT CIRCULARBEAM INTO SLIT -SHAPED CROSS SECTION

DC ONLY

56

111

MAGNETIC SECTOR MASS ANALYZER

+ ION MOVING THRU MAGNETIC FIELD STRENGTH B

Fm = MAGNETIC FORCEALWAYS ACTS PERPENDICULAR TO DIR. OF MOTION

B

Fm

Fm

Fm

v

v

v

112EXAMPLE

B = 103 Gauss m = 100 z = +1 m/z = 100V = 2000 volts

rm = 64 cm

m

z =

B r

2 V

2m2

SCAN m/z BY SCANNING EITHER:

B (vary mag. field)V (vary acc. voltage) AND / ORrm (array detector)

57

113ELECTROSTATIC 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)

r e = 2V/E = 2Vd/ V′′′′

114

Object

le′′′′ le″″″″

radius reangle φφφφe

(+)

(-)Image

FOCUSING PROPERTIES

58

115

FOCUSING EQN. MAGNETIC SECTOR

NORMAL (PERPENDICULAR) ION ENTRYSOURCE, CENTER OF CURVATURE & IMAGE ALL ON SAME LINE

Source Image

B

rm

φm2α

lm′lm″

*SELECT l m′′′′, lm″″″″, φφφφm , rm TO PROVIDE FOCUSED IMAGE?

116

7 ions start m/z = 200∆∆∆∆ m/z = 20

320

280

240

200

MASS DISPERSION

59

117

7 ions m/z = 200KE = 2000 eV∆ ∆ ∆ ∆ KE = 10 eV

BEAM BROADENINGBY SPREAD OFKINETIC ENERGY

118

7 ions m/z = 200∆∆∆∆ injection angle = 1o

FOCUSING EFFECTIONS INJECTED OVERVARIOUS ANGLES

Finnigan Element Demo

60

119

120NU INSTRUMENTS

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

61

121

Isotope Mass Interferant Mass Resolution 28Si 27.9769 N2 28.0061 960 31P 30.9738 NOH 31.0058 970

32S 31.9721 O2 31.9898 1800 39K 38.9637 ArH 38.9706 5700 51V 50.9440 ClO 50.9638 2600 56Fe 55.9349 ArO 55.9573 2500 75As 74.9216 ArCl 74.9323 7800 80Se 79.9165 Ar2 79.9248 9700

0

10

20

30

40

50

60

70

80

90

100

0 2000 4000 6000 8000 10000 12000 14000

Resolution (R=M/DeltaM)

Tra

nsm

ission (%

)

0

10

20

30

40

50

60

70

80

90

100

0 2000 4000 6000 8000 10000 12000 14000

Resolution (R=M/DeltaM)

Tra

nsm

ission (%

)

Variable Resolution

Resolution can be optimised for specific applications and sensitivity does not have to be compromised by “over-resolution”.

122

ArO56Fe

Separation of Analyte from Interfering Species

Separation of 80Se from Ar2Separation of 56Fe from ArO

Flat top peak – Interference-free

analysis of transition elements

80Se Ar2

Triangular peak shape but separated peaks

– Sample quantification in complex matrixes

62

123attoM Scanning Modes

• Magnetic Scanning– Slow – 0.1 sec per step

– Conventional mass scanning

– For small mass ranges

– Instrument tuning

– High resolution

Fast Magnetic Scanning 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

124attoM Scanning Modes

Optimises analysis time

Combination of Fast Magnetic Scanning and FastScan Ion Optics

63

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 mid-point 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.

64

127NIST 610 glass Pb isotopes40 µµµµm spot MICROMASS ISOPROBE

spot 207Pb/206Pb %1se 208Pb/206Pb %1se 208Pb/204Pb %1se

1 0.91757 0.02 2.20277 0.01 38.54770 0.03

2 0.91747 0.01 2.20253 0.01 38.58310 0.03

3 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

mean 0.91743 2.19867 38.50500

1SD 0.00015 0.00670 0.10655

%1SD 0.02 0.30 0.28

128SPECTRO MS MATTAUCH-HERZOG GEOMETRY WITH MULTICHANNEL DETECTOR

QUADLENS

ENT SLIT

ESA

MAGNET

SOLID-STATEARRAYDETECTOR

65

129ICP-TOF-MS

RAY & HIEFTJE, JAAS 2001, 16, 1206-1216.

GUILHAUS et al. MASS SPECTROM. REVIEWS 2000, 19, 65-107.

130GBC OPTIMASS 8000Orthogonal Acceleration - TOF MS

RF Generator

Gas Control Unit

PeristalticPump

SprayChamber

Impedance

Matching

Network

Plasma Torch

RotaryVacuumPump

Turbo 3Turbo 2

Turbo 1

Pre-ampDetector

IonReflectron

IonBlanker

Liner

Collector

OrthogonalAccelerator

3-coneInterface

IonOptics

GateValve

66

131

CyTOFDVS SCIENCES

132

MATRIX EFFECTS

67

133

SOLIDS DEPOSITION IN ICP-MSDouglas & Kerr, JAAS 1988, 3, 744

1% Na or K

U

ZrCa

Al

134

MATRIX EFFECTOlivares & Houk, Anal. Chem 1986, 58, 20.

68

135

VARIATION OF SIGNAL & MATRIX EFFECTWITH NEB. GAS FLOW Tan & Horlick JAAS 1987, 2, 745.

136YO, Y(I), Y(II) EMISSION ZONESCOURTESY VARIAN

69

137

138

70

139

Gillson, Tanner, Douglas

140

Co+

Trajectories

80% Ar+

20% O+

80% Ar+

19% O+

1% U+

71

141INTERNAL STANDARD

Co+

142Standard AdditionsCa Calibration in 38% HF (w/w)

PFA-100, PFA endcap, Pt injector

Cool plasma conditions

Tamapure HF Grade AA10

72

143MARINE SEDIMENT REF. MATERIAL BCSS-1, 0.1%McLaren et al. JAAS 1987

CONCENTRATIONS (µg/g ± std dev, n = 4)External Standard Accepted (info)

Element Calibration Addition Value

V 71 ± 3 93 ± 16 93 ± 5Mn 156 ± 8 220 ± 19 229 ± 15Co 8.9 ± 0.2 13 ± 3 11 ± 2Ni 43 ± 1 57 ± 6 55 ± 4Cu 24 ± 1 29 ± 3 19 ± 3Zn 124 ± 8 123 ± 5 119 ± 12

As 14 ± 1 12 ± 1 11 ± 1Mo 3.0 ± 0.1 1.8 ± 0.2 (1.9)Cd 0.26 ± 0.02 0.27 ± 0.03 0.25 ± 0.04Pb 22 ± 1 23 ± 2 23 ± 3

144

ISOTOPE DILUTION

Beauchemin et al., Anal. Chem. 1987, 59, 610.

73

145

146REMOVE POLYATOMIC IONS?

ALTER ICP:

COOL PLASMA

SOLVENT REMOVAL

REMOVE/SEPARATE POLY. IONS FROM M + ANALYTE IONS:

HIGH RESOLUTION

COLLISION CELLS

74

147GOOD IE BAD IE D 0GUYS/GALS (eV) GUYS (eV) (eV)S+ 10.36 O2

+ 12.063 6.663

Fe+ 7.87 ArO+ ~ 13 0.312ArN + ~14 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

148

SOLVENT REMOVAL

REDUCE MO+ (also KE discrimination)

ANALYSIS OF ORGANIC SOLVENTS

IMPROVE SENSITIVITY,ESP. FOR SECTOR INSTRUMENTS (?)

75

149

Elemental Scientific Inc.MicroFlow PFA Nebulizer

• 100% Teflon

• Self-aspiration:– 20 µL/min

– 50 µL/min

– 100 µL/min

– 400 µL/min

150

Aerosol out

CoolantDrain

SPRAY CHAMBER & SOLVENT REMOVAL

76

151

CYCLONE SPRAY CHAMBER

152

Comparison of desolvation methodsJAAS 1998, 13, 167-174.

77

153

154

DESOLVATION SYSTEM FOR MICRONEBULIZERCETAC ARIDUS

78

155

Elemental Scientific Inc.Apex

Heated Cyclonic SC(120C/140C)

Peltier-Cooled Multipass Condenser2C/-5C

Total Internal Volume 180 ml

156

50 ppq CeApex + Element

79

157Elemental Scientific Inc.Apex FAST Diagram

158

CeO+

CeO+/Ce+

= 0.03%

Apex + Spiro 100 pptIn and Ce

80

159Membrane Reduction of ArCl+

Apex-Spiro Teflon Membrane Desolvator

*LARGE SENSITIVITYENHANCEMENT FOR As +!

160

81

161COOL ICP

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 IONSFROM REGION WHERE NO +, O2

+ AND/OR H3O+

ARE MAJOR BACKGROUND IONS

SECONDARY DISCHARGE DUE TO POTENTIAL GRADIENTCOUPLED 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 SHIELDINSERTED BETWEENCOIL AND TORCHPREVENTS CAPACTIVE COUPLINGBETWEEN LOAD COIL & PLASMA

82

163

INTERLACED LOAD COIL, VARIAN/BRUKER

+HV 0

0 -HV

POTENTIAL GRADIENTSALONG EACH COIL OFFSET

LOW PLASMA POTENTIAL

164COOL PLASMA CHARACTERISTICS

TANNER, JAAS 1995, 10, 908ELAN 6000

HOT COOL

POWER 1200 W 600

AEROSOL GAS 0.77 L/min 1.08

SAMPLING 9.0 mm 9.0POSITION

SPRAY Room temp Room tempCHAMBER

83

165

85807570656055504540353025201510510 0

10 1

10 2

10 3

10 4

10 5

10 6

10 7

10 8

10 9

10 10

Mass

ion

sig

nal

/ cp

s

O+ Ar+

ArH+

ArO+ Ar2+

a

BACKGROUND SPECTRUM HOT PLASMA

166YO, Y(I), Y(II) EMISSION ZONESCOURTESY VARIAN

84

167

85807570656055504540353025201510510 0

10 1

10 2

10 3

10 4

10 5

10 6

10 7

10 8

Mass

ion

sig

nal

/ cp

s

H3O+ NO+ O2+

Ar+

ArH+

Fe+ & ArO+ Ar2+

b

BACKGROUND SPECTRUM COOL PLASMA

168

85

169COLLISION CELLS

Rowan & Houk, Appl. Spectrosc. 1989, 43, 976.Douglas, Canad. J. Spectrosc. 1989, 34, 38.King & Harrison, Int. J. Mass Spectrom. Ion Processes1989, 89, 171.

Turner, Speakman et al., Plasma Source MS, Developments & Applications, Royal Society, 1997, p. 28.

Baranov & Tanner, JAAS 1999, 14, 1133JASMS 1999, 10, 1083.

USE COLLISION - INDUCED DISSOCIATION (CID) &/OR CHEMICAL REACTION TO REMOVE POLY. IONS

RETAIN ATOMIC ANALYTE IONSREDUCE KE & SPREAD OF KE OF POLY IONS

170

MULTIPOLE COLLISION CELLSFOR REMOVING POLYATOMIC IONSIN ICP-MS

GV PLATFORM (QUADRUPOLE)ISOPROBE

PE SCIEX DYNAMIC REACTION CELL

THERMO X2

AGILENT 7700

86

171GOOD IE BAD IE D 0GUYS/GALS (eV) GUYS (eV) (eV)S+ 10.36 O2

+ 12.063 6.663

Fe+ 7.87 ArO+ ~ 13 0.312ArN + ~14 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

172ICP PLATFORM, MICROMASS LTD.

HEX BIAS= -2.0 VOLTS

QUAD BIAS= + 3.0 VOLTS

87

173

Ion Signal vs. He Gas Flow Rate

0

0.5

1

1.5

2

2.5

3

0 2 4 6 8 10

Li

Ni

In

U

Hex Bias -2.2, IE = 1.0, Mult = 482, H2 = 0 ml/min

No

rmal

ized

Sig

nal

He Gas Flow Rate (ml/min)

174MICROMASS PLATFORM

40Ar 2+

88

175

QUAD POLE BIAS (volts)1 2 3 4 5

RE

L. S

IGN

AL

0

50

100

V+, Sr+

ArH 3O+

HEXAPOLE BIAS = -2 volts

*POSITIVE STOPPING VOLTAGE ON QUAD REJECTS MOST POLY. IONS

176

ions from source

conversion of reactive ions

mass analysis of transmitted ions

ions to detector

isobaranalyteother m/z

reaction gas inreaction cellmass analyzer

DYNAMIC REACTION CELL (DRC)

89

177

178DRC + AFT SIDE VIEW

DRCRODS

AFTELECTRODEVappl ~ 300 volts DC

QUAD RODSIN DRC

AFT ELECTRODES

90

179

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)

1

10

100

1000

1e4

1e5

1e6

1e7

m/z = 801 ppb Se80Se+ + CH4 → no rxn.

m/z = 781 ppb Sem/z = 821 ppb Sem/z = 80 blank

40Ar2+ + CH4 → prods

m/z = 78 blank38Ar40Ar+ + CH4

→ prods

REACTION PROFILES

m/z = 80 1 ppb Se40Ar2

+ + CH4 → prods

180

m/z = 75

ION

SIG

NA

L

1 ppb As750 c/s

1 ppb As+ 1000 ppm NaCl

1000 ppm NaCl25 c/s

DIW

DEATH TO ArCl + !

91

DL and BEC of ELAN DRCESI PFA Nebulizer, Y. Kishi & K. Kawabata

Unit: ppt Integration time: 1 secBrown color: DRC mode

Element DL BEC Element DL BECLi (7) 0.26 0.22 Ge (74) 0.58 0.57Be (9) 1.00 0.87 As (75) 0.48 1.60B (11) 3.60 7.10 Sr (88) 0.03 0.02

Na (23) 0.20 0.22 Zr (90) 0.05 0.04Mg (24) 0.23 0.18 Mo (98) 0.11 0.12Al (27) 0.23 0.42 Ag (107) 0.09 0.10K (39) 0.27 2.60 Cd (114) 0.08 0.11

Ca (40) 0.27 0.63 In (115) 0.03 0.02Ti (48) 0.92 1.70 Sn (120) 0.12 0.88V (51) 0.12 0.04 Sb (121) 0.08 0.08Cr (52) 0.14 0.29 Ba (138) 0.06 0.04Mn (55) 0.17 0.54 Ta (181) 0.06 0.05Fe (56) 0.49 2.60 W (184) 0.07 0.07Ni (60) 0.43 0.66 Au (197) 0.15 0.05Co (59) 0.04 0.04 Tl (205) 0.02 0.01Cu (63) 0.06 0.68 Pb (208) 0.07 0.09Zn (64) 0.63 1.20 Bi (209) 0.02 0.01Ga (69) 0.06 0.05 U (238) 0.02 0.01

182THERMODYNAMICS OF ION-NEUTRAL RXNS

Ar 2+ + e- →→→→ Ar 2 -Int E(Ar 2

+) ~ 15.76 – 1.25 ~ -14.5 eV

CH4 →→→→ CH4+ + e- IE(CH 4) = 12.6

Ar 2+ + CH4 →→→→ Ar 2 + CH4

+ ∆H = IE(CH 4) – Int E(Ar 2) ~ -1.9 eV

EXOTHERMIC RXN USUALLY RAPID, EXTENSIVE

CH4 →→→→ CH4+ + e- IE(CH 4) = 12.6

Se+ + e- →→→→ Se -IE(Se) = -9.75

Se+ + CH4 →→→→ Se + CH4+ ∆H = IE(CH 4) – IE(Se) ~ +2.8 eV

ENDOTHERMIC RXN, SLOWERKEEP COLLISION ENERGY LOW

92

183

q = 2V/(m/z)r02ωωωω2

a = 0Select cutoffwith q

184

Low q0.2ManyProductIons

High q0.8Precursor &ProductIonsSuppressed

Fe(NH3)n+ CLUSTERS

93

185

186

94

187PE NEXION

188PE NEXION

95

189

190KINETIC ENERGY DISCRIMINATION

COLL CELL LENGTH L = 10 cmGAS DENSITY n

ION HAS CROSS SECTION ΩΩΩΩ (cm2)

NUMBER OF COLLISIONS = L/ λ = L n ΩΩΩΩλ = mean free path (cm)

EXPECT ~ 5 TO 10 COLLISIONS

POLY ION IS LARGERLARGER ΩΩΩΩMORE COLLISIONS IN SAME LENGTH L

96

191

( )

( )He with ArO and Fe of collfor 0.88

56 4

56 4~

m m

m m ~ collper remaining KE ofFraction

TIONDISCRIMINA KE & LOSSES KE

2

22

2iongas coll

2ion

2gas coll

++=++

++

=

α

α

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

0

100

200

300

400

500

600

00.4

0.8

1.2

1.6 2

Analyte

Interferent

KE

N

KINETIC ENERGY DISCRIMINATION

NO COLL. GAS

97

193

0

100

200

300

400

500

600

00.4

0.8

1.2

1.6 2

Analyte

Interferent

KE

N

POLY. ION HAS LARGER CROSS SECTION FOR KE LOSS

POTENTIAL BARRIERSTOPS POLY. IONS

194

AGILENT 7500cs OCTOPOLE COLLISION CELL

98

195

AGILENT 7500 cs (now 7700)

OMEGALENS

196

99

197Acid Matrices & IPA in NoGas Mode

(HNO3 + HCl + H2SO4 + IPA)

NoGas Mode

Unspiked 5% HNO3 + 5% HCl + 1% H2SO4 + 1% IPA Matrix

Unspiked Matrix – ALL peaks are due to polyatomic interferences

What happens to all these polyatomics in He Mode?

Multiple polyatomic interferences affect almost every

mass – Interferences are matrix-dependent

2E5

cps

198Single Acid Matrices and IPA in He Mode

(HNO3 + HCl + H2SO4 + IPA)

He Mode

All polyatomic interferences are removed in He Mode

Unspiked 5% HNO3 + 5% HCl + 1% H2SO4 + 1% IPA Matrix

ALL polyatomic interferences are removed in He Mode (same cell conditions)2E5

cps

100

199AGILENT 8800

200

Thermo X Series 2 w CCT

Xt or Xs interface

Extraction Lens

Pi Lens L1 & 2

HexapoleCollision Cell

Exit Lens L3

Focus Lens

Chicane deflector D1&

2

QuadrupoleMass Filter

Discrete Dynode Detector

101

201Single Gas and Flow Rate Removes Various Poly Ions

1

10

100

1000

10000

100000

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 Flow Rate (ml/min)

Lo

g S

ign

al In

ten

sity

(ic

ps)

0.001

0.01

0.1

1

BE

C (

pp

b)

52Cr Unpiked52Cr SpikedBEC

1

10

100

1000

10000

100000

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)

Sig

nal

Inte

nsi

ty (

icp

s)0.01

0.1

1

10

100

BE

C (

pp

b)

51V Unspiked51V SpikedBEC

1

10

100

1000

10000

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)

Log

Sig

nal

Inte

nsi

ty (

icps

)

0.001

0.01

0.1

1

BE

C (p

pb)

60Ni Unpiked60Ni SpikedBEC

1

10

100

1000

10000

100000

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)

Sig

nal

Inte

nsi

ty (

icps

)

0.0001

0.001

0.01

0.1

1

BE

C (

ppb

)

59Co Unspiked

59Co Spiked

BEC

1

10

100

1000

10000

100000

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)

Sig

nal

Inte

nsity

(icp

s)

0.01

0.1

1

10

BE

C (p

pb

)

63Cu Unspiked

63Cu SpikedBEC

1

10

100

1000

10000

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)

Sig

nal

Inte

nsi

ty (

icp

s)

0.01

0.1

1

10

BE

C (

pp

b)

75As Unspiked75As SpikedBEC

All interferences removed under 1 simple set of conditions!

ClO, ClOH, ArC ClO CaO,

CaOH

Cell gas flow optimisations performed in 1:10 diluted seawater

CaO NaAr ArCl

202

Interference Removal - ICSA

Shows measured concentrations for 6020A ICSA solution in standard mode (without interference correction) and He cell mode

102

203

He KED Mode for REEs• 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%

204COLLISION REACTION INTERFACEVARIAN/BRUKERKALINITCHENKO et al.

ICP

SAMPLER

SKIMMER+ 74 mL/min H2

or 110 mL/min He

103

205

206

104

207SeronormUrine 2525

208ACKNOWLEDGMENTS

CETACELEMENTAL SCIENTIFICTHERMO FINNIGANGV (MICROMASS)PE SCIEX/SCIEXLECOAGILENT VARIAN/BRUKERSPECTRO

105

209IONIZATION IN ICP

T = 7500 K ne = 1 x 1015 cm-3

Y Zr Nb

La Ta

Ac

Co Cu Zn

B C N O F

He

Ne

Al Si P S Cl Ar

Ga Ge As Se Br Kr

Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

W Re Os Ir Pt Au Hg Tl Pb Po At Rn

Cr Mn Fe Ni

Hf Bi

Fr Ra

Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lw

H

Li Be

Na

K Ca

Rb Sr

Cs Ba

VSc Ti

0.1

100 75

100 98Mg

100 100 99 99 98 95 96 93 91 90 75 90

98

98

98 94 93 93 8596

94 93 78 62 51 38 100

99 96 78 66 29 8.5

92

58 5 0.1 0.1 9e-4 6e-6

85 33 14 0.9 0.04

52 33 5 0.6

100

100

96,4

91,9

98

90,10

99,1

97,0.0196 95

96,2 90,10 99* 97,3 100* 93,7 99* 100*

100* 100*

99* 91,9 92,8

99 98

*These elements also make M+2

M+/(M+ + M) (%)

%M +2