M. TiepoloM. TiepoloC.N.R.C.N.R.--Istituto diIstituto di GeoscienzeGeoscienze ee GeorisorseGeorisorse Sezione di Pavia,Sezione di Pavia, ItalyItaly

Thanks to: C. Bouman, B. Narcisi, F. Schiavi, M. Palenzona, J-L. Paquette, M.R. Renna, R. Tribuzio, R. Vannucci, A. Zanetti

InIn--situ trace element and isotope situ trace element and isotope determinations with laser ablationdeterminations with laser ablation

(LA)(LA)--HRHR--ICPMS & (LA)ICPMS & (LA)--MCMC--ICPMSICPMS

GeochemistryGeochemistry of the of the solidsolid EarthEarth

0.1

1

10

100

Li KBaRbThUNbTaLaCeSrPbNdSmEuGdZrHfTiDyYYb

Am

ph

/C1

Radiogenic & Stable isotopesTrace elements

Geochronology

Trace element 5-10%

Approximate scale of Approximate scale of precisionprecision

Geochronology (U-Pb) 1-2%

Isotope geochemistry << 1%

Laser ablation (LA)Laser ablation (LA)--ICPICP--MSMSLaser sourceLaser source

•• High spatial resolutionHigh spatial resolution•• Efficient ablation on most of Efficient ablation on most of

materialsmaterials

•• High ionization efficiency of High ionization efficiency of the ICP sourcethe ICP source

•• High sensitivityHigh sensitivity

ICP mass spectrometerICP mass spectrometer

+

Earth Sciences, environmental sciences, biological sciences, forensic sciences, semiconductors

Trace element and isotopic determinations

Examples of materials where the Examples of materials where the in situin situ approach is requiredapproach is required

1 cm1 cm

100 µm100 µm 100 µm 100 100 µµmm

Tree ring analysesRocks & Minerals Volcanic ashes

Laser wavelengths and laser pitsLaser wavelengths and laser pits266 nm Nd:YAG laser 193 nm ArF Excimer laser

50 µm 100 µm

Ablation efficiency is a function of:-Laser wavelength (E193 > E266)-Material (UV transparency)

The ablation processThe ablation process

100 µm

266 nm5.0 mW20Hz

BCR-2Basaltic glass

Sensitivity in laser ablationSensitivity in laser ablation(Dry plasma)(Dry plasma)

Signal from laser ablation is about 100,000 times lower than that from solution nebulisation.

example

1x109 cps/ppm In → 1x104 cps/ppm In

This enormous difference is mainly related to the poor efficiency of the ICP torch in ionising the

particulate produced by laser ablation.

The laser ablation signalThe laser ablation signal1. Highly transient (signal decrease with time/depth)2. Limited in time (~ 2 minutes of signal)

100

1000

10000

100000

1000000

10000000

0 50 100 150 200scans

cps

44Ca

93Nb

208PbBackground

Signal

Signal acquisitionSignal acquisitionSimultaneousSimultaneous vs. vs. SequentialSequential

Multi-collector

Single collector∆t

(44Ca/208Pb)m = f [∆t ; (44Ca/208Pb)S]

Requirements of the ICPMSRequirements of the ICPMS

• High sensitivity (high signal/background ratio)

• Multi–element analysis

High scan speed

• Isotope analysisHigh abundance sensitivityFlat top peaks (Possibly) multi collectors

ICPMS and applicationsICPMS and applications

• Q-ICP-MS → highest scan speed– Multi-element analysis

• HR-ICPMS → high sensitivity – relatively high scan speed – flat top peaks

– Multi element analysis (depleted samples)– Basic isotope analysis (Pb geochronology)

• MC-ICP-MS → high sensitivity - multi collector – no dynamic scan– Advanced isotope analysis– No multi element analysis

SINGLE COLLECTOR SINGLE COLLECTOR HIGH RESOLUTION HIGH RESOLUTION

(HR)(HR)--ICPMSICPMS

Multi element analyses withMulti element analyses withLALA--HRHR--ICPMSICPMS

Nd:Yag 266 nm ArF Excimer 193 nm

Element I(ThermoFinnigan)

Upgraded to Element II for:• Capacitive decoupling torch• Magnet• Magnet field regulator

Layout of the HRLayout of the HR--ICPMSICPMS

from ThermoFinnigan

Response curveResponse curveIsotopic abundance normalizedIsotopic abundance normalizedC

ps/

pp

m

1.E+03

1.E+04

1.E+05

Mg25

Si29

Ca43

Ca44

Sc45

Ti49

V51

Cr53

Rb85

Sr88

Y89

Zr90

Nb93

Cs133

Ba137

La139

Ce140

Pr141

Nd146

Sm149

Eu151

Gd157

Tb159

Dy163

Ho165

Er167

Tm169

Yb173

Lu175

Hf177

Ta181

Pb208

Th232

U238

Conventional torch

Capacitive Decoupling torch

In He ablationLaser frequency: 10HzLaser Power 2.2 mW 40 µm spot size

NIST 612NIST 612

“High power “High power magnetmagnet fieldfield regulatorregulator””

0.000

0.200

0.400

0.600

0.800

1.000

1.200

0 50 100 150 200 250

mass (a.m.u.)

Set

tlin

g T

ime

/ a.m

.u. (

ms)

from ThermoFinnigan

m/z 7-238 230 msm/z 7-238 75 ms

Old field regulator

New field regulator

“Flat top” peaks“Flat top” peaks

207Pb

208Pb

Multi element determinations (Low Res.)Multi element determinations (Low Res.)

Scan time: 624 ms7Li

25Mg29Si

43Ca51V

85Rb

133Cs

157Gd

→ 44Ca→ 45Sc → 49Ti→ 53Cr→ 59Co

→ 88Sr→ 89Y → 90Zr → 93Nb

→137Ba→ 139La → 140Ce → 141Pr →146Nd → 149Sm→ 151Eu

→159Tb→ 163Dy → 165Ho → 167Er →169Tm → 173Yb→ 175Lu → 177Hf → 181Ta

isotope6Li7Li9Be11B

25Mg29Si44Ca

6Li → 44Ca

Total scan time: 196 ms Acquisition efficiency: 60%

B-scan

E-scan

7Li → 238U (36 masses)6Li

208Pb →232Th→ 238U

All masses are almost free from interferences and XO+/X+ ratio < 1%

Data Data acquisitionacquisition 1 minute Background – 1 minute Signal

Standard NIST 610/612

Standard NIST 610/612

7 unknown

Reference material (BCR-2

8 unknown

Standard NIST 610/612

Standard NIST 610/612

7 unknown

RSFIIC

C STDi

SAMPi

STDiSAMP

i ⋅⋅

=

SAMPis

STDis

SAMPis

STDis

CIICRSF ⋅

=

PrecisionPrecisionUSGS - BCR-2 (basalt glass)

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

55%

60%

Sc45

Ti49 V51Cr53Co5

9Rb8

5Sr88 Y89Zr90Nb9

3Cs1

33Ba1

37La

139

Ce140

Pr141

Nd146

Sm149

Eu151

Gd157

Tb159

Dy163

Ho165

Er167

Tm169

Yb173

Lu17

5Hf17

7Ta1

81Pb2

08Th2

32U23

8

Pre

cis

ion

(1r.

s.d

. %

)

50 µm 10Hz10 µm 10Hz

193 ArF Excimer laser18 % -

4% -

AccuracyAccuracy(extended trace elements)USGS - BCR-2 (basalt glass) MPI-DING GOR 128-G

40 µm spot size

Reference value (ppm)1 10 100 1000

Mea

sure

d va

lue

(ppm

)

1

10

100

1000

Lu

TaTb

Ho

YbHf

Tm

Cs

Er

U Eu

Gd DyTh

Sm

PbNb

Pr Li

Nd

Cr

La

Ce

Y

RbSc

Co

Zr

Sr

V Ba 40 µm spot size

Reference value (ppm)0.001 0.01 0.1 1 10 100

0.001

0.01

0.1

1

10

100

Th

UTa

PrLa Eu

TbTm

Lu

Hf

Ho

Hf

Sm

Nd

Nb

Ba

Gd

Er

Dy

Yb

Rb

Sc

SrYZr

Cs

Pb

AccuracyAccuracy Light lithophile elements

reference value (ppm)0.1 1 10 100

mea

sure

d va

lue

(ppm

)

0.1

1

10

100

LithiumBerylliumBoron

Nist 616

Nist 612

StHs6/80-GGOR 128-G

GOR 132-G

T1-GML3B-G

T1-G

StHs6/80-G

ML3B-G

Limits of detection (Limits of detection (3σRnet/S)1 ppm

1 ppb

NIST 61250 µm - 2.8 mW

In He ablationLaser frequency: 10Hz

Spot size

5 µm

1

0,1

0,01

0,001

0,0001

0,00001Li Sc Ti V CrCoRb Sr Y ZrNbCs Ba LaCe Pr NdSmEuGdTbDyHo ErTmYbLu Hf Ta Pb Th U

Limits of detection (LLE)Limits of detection (LLE)

0.000

0.200

0.400

0.600

0.800

1.000

1.200

66LiLi 77LiLi 99BeBe 1111BB

limits

of d

etec

tion

(lim

its o

f det

ectio

n ( p

pmppm

))

This work 266 nm (40 µm spot)This work 213 nm (40 µm spot)Gao et al., 2002 (60 µm spot)Kurosawa et al., 2002 (80 µm spot)

1 ppm

Q-ICPMS

Clinopyroxene from forearcperidotites from Western Pacific

Ocean0.001

0.01

0.1

1

10

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

Cpx

/C1

Clinopyroxene from Zagadochnaya kimberlite (Siberian craton of Yakutia, Russia)

0.1

1

10

100

1000

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

Cpx

/C1

Z1-5

Z3-4

Volcanic ash in Ice cores from Volcanic ash in Ice cores from Antarctica (5Antarctica (5µµm m –– 193 nm)193 nm)

0.01

0.10

1.00

10.00

100.00

1000.00

Ba Rb Th U Nb Ta La Ce Sr Nd Sm Zr Hf Ti Dy Y Yb

N-M

OR

B n

orm

alis

ed

EPICA ashes

APPLICATIONSAPPLICATIONS::1) Geological samples

APPLICATIONSAPPLICATIONS::2) Human and animal bones

Con

cen

trat

ion

(p

pm

)

HumanHumanHorseHorse DogDog Roman age

1000

100

10

1

0,1

0,01Li Sc Ti V Cr Co Rb Sr Y Zr Nb Cs Ba La Ce Pr Nd Sm Pb Th U

APPLICATIONSAPPLICATIONS::3) Tree rings

0,0100

0,1000

1,000018

80

1890

1900

1910

1920

1930

1940

1950

1960

1970

1980

1990

Nor

mal

ised

to

25M

g

Pb

oakoak fromfrom “Parco “Parco del Ticino”del Ticino”

18802000

2000

UU--ThTh--Pb Pb GeochronologyGeochronology(LA)(LA)--HRHR--ICPICP--MSMS

•• 238238U U →→ 206206Pb Pb •• 235235U U →→ 207207Pb Pb •• 232232Th Th →→ 208208PbPb

ZirconZircon –– MonaziteMonazite

ZirconZircon –– 213 213 nm

0.080

0.084

0.088

0.092

0.096

0.100

0.104

0.108

0.62 0.66 0.70 0.74 0.78 0.82 0.86 0.90

207Pb/235U

206 P

b/23

8 U

500

540

580

620

Zircon GRMTIMS: 577 ± 8 Ma

σ

573 ± 4.4 (2573 ± 4.4 (2σσ) Ma) Ma

40 µm

nm

InternalInternal precisionprecision (2(2σσ) : 1.0%) : 1.0%

InternalInternal precisionprecision (2(2σσ) : 1.5%) : 1.5%

40 40 µµmm

20 20 µµmm

On single age determinations:

0.080

0.084

0.088

0.092

0.096

0.100

0.104

0.108

0.62 0.66 0.70 0.74 0.78 0.82 0.86 0.90

207Pb/235U

206 P

b/23

8 U

500

540

580

620

Zircon GRMTIMS: 577 ± 8 Ma

583 ± 9 (2583 ± 9 (2σσ) Ma) Ma

20 µm

360

340

320

300

280

260

240

2200.034

0.038

0.042

0.046

0.050

0.054

0.058data-point error ellipses are 2

Zircon 02123TIMS 295 MA

20 µm

296 ±1 (2σ) Ma

Pb

/23

8U

20

6

0.24 0.28 0.32 0.36 0.40 0.44207Pb/235U

40 µm

529 ± 16 Ma

716 ± 18 Ma

Zircons with inherited components Zircons with inherited components Internal Internal LigurideLiguride ophiolites ophiolites (Northern Apennine, Italy)(Northern Apennine, Italy)

340

300

260

220

180

140

100

60

20

data-point error ellipses are 2σ

Mean age 156 ± 4 Ma

0.06

0.05

0.04

Pb

/238 U

0.03

206

0.02

0.01

AntampombatoAntampombato--AmbatovyAmbatovy intrusion intrusion (Madagascar(Madagascar)

0.000.0 0.1 0.2 0.3 0.4

) 207Pb/235U

10000

120 110 100 90 80

to common Pb

Intercept age at 89 ±6 Ma

0.28

10000.24

1000.20

0.001

0.01

0.1

1

10

Rb Ba Nb Ta La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

zirc

on/C

1

20

6 Pb

0.16

0.00

0.04

0.08

0.12

20

7 Pb

/

50 60 70 80 90

238U/206Pb

MonaziteMonazite –– 193193 ArF ExcimerArF Excimer laserlaser5 5 µµm spot m spot sizesize

0.077

0.079

0.081

0.083

0.085

0.087

0.089

0.59 0.61 0.63 0.65 0.67 0.69 0.71207Pb/235U

206P

b/23

8U

Concordia Age 514.2 ±3.8 Ma

(95% conf.)

data-point error ellipses are 2σ

480

500

520

540

Mean 208Pb/232Th age532.8 ± 4.0

[0.76%] 95% conf.

208Pb/232Th ages

TIMS Age on zircons: 540 Ma

600

580

560

540

520

500

480

MULTI COLLECTOR MULTI COLLECTOR (MC)(MC)--ICPMSICPMS

11B/10B ratiosδ11B‰=[(11B/10B)sample/(11B/10B)SRM951)-1]X1000)

Major impediments in measuring δ11B with Laser ablation MC-ICP-MS:

•ICP-MS– Low sensitivity for light masses– Faraday detectors require several hundreds ppm

B in the sample for a precise 11B/10B determination under laser ablation

•B concentration– With the exception of a few minerals (e.g.

tourmaline), B abundance is usually below 100ppm and even below 1 ppm in mantle environments.

•Availability of standards

The LAThe LA--MCMC--ICPICP--MS instrument MS instrument • Laser ablation system

– Commercial UP213 from NewWave working at 213 nm.– The laser was operated in single spot mode with a repetition rate

of 10 Hz and a spot size from 60 to 80 µm in diameter.

• MC-ICP-MS– The Finnigan Neptune (Thermo), – Equipped with both multiple ion counters and Faraday cups.

0

10000

20000

30000

40000

50000

60000

10.545 10.550 10.555 10.560 10.565 10.570

Mass

bo

th t

rac

es

no

rma

lise

d t

o 11

B (

cp

s) 11B

10B

DetectorDetectorConfigurationConfiguration

1111B/B/1010B acquisitionB acquisition

3.4

3.6

3.8

4.0

4.2

4.4

4.6

4.8

0 10 20 30 40 50 60 70 80 90 100

cycle

Raw

11B

/10B

Faraday

Ion counters

NIST SRM 610B = 350 ppm

Isotope FractionationIsotope Fractionation1.1. Instrumental Mass bias Instrumental Mass bias

(13(13--14%)14%)

2.2. Laser induced fractionationLaser induced fractionation

3.3. Drift of detector (MIC)Drift of detector (MIC)

Isotope fractionation

B4 Tourmaline

-0.0015%

-0.0010%

-0.0005%

0.0000%

0.0005%

0.0010%

0.0015%

0.0020%

0 1 2 3 4 5 6 7

11B

/10B

fra

ctio

nat

ion

s-1

NIST SRM 610 4.60

4.39

y = -0.0030x + 4.5499

y = -0.0033x + 4.3439

Day1

Day2

MIC calibration

y = -0.0035x + 4.3451

y = -0.0032x + 4.3715

GOR132-G

NIST SRM 610

4.55

4.374.50

4.454.35

4.10

4.15

4.20

4.25

4.30

4.35

4.40

1 4 7 10 13 16 19 22 25 28 31 34 3analysis #

7 40 43 46 49 52 55 58 61 64

raw

11B

/10B

4.27

4.29

4.31

4.3311

B/10

B r

aw

1 2 3 4 5 6 7 8 9 10 11 12 1

analysis #3 14 15 18 19 20 21

Analytical MethodAnalytical MethodCorrection of:Mass bias – laser induced isotopic fractionation – ion counter drift

accepted

NIST61010

11

measured2

NIST61010

11measured1

NIST61010

11

measured

unknown10

11corrected

unknown10

11

BB

12

BB

BB

BB

BB

×+

=

standard sample standard sample standard

External standard Nist 610 – 11B/10B = 4.0490 (le Roux et al., 2004)

FaradayFaraday –– B4 tourmaline and B4 tourmaline and NistNist 610610Sample 11B/10Bmeas sd r.s.d.Nist610 4.6833 0.0027 0.058%B4 4.6268 0.0001 0.003%Nist610 4.6662 0.0025 0.053%B4 4.6276 0.0002 0.005%Nist610 4.6631 0.0022 0.048%B4 4.6269 0.0001 0.002%Nist610 4.6627 0.0024 0.052%B4 4.6272 0.0001 0.002%Nist610 4.6657 0.0021 0.046%B4 4.6274 0.0001 0.003%Nist610 4.6669 0.0025 0.053%B4 4.6270 0.0001 0.002%Nist610 4.6551 0.0020 0.043%

AveragesB4 4.6272 0.00031 0.007%Nist610 4.6649 0.00191 0.041%

B4 = 31400 ppm BNist610 = 350 ppm B

δ11B = 8.41 ± 0.34‰

Multi Multi IonIon CountersCounters –– StHs6/80StHs6/80Sample 11B/10Bmeas sd r.s.d.Nist610 4.3839 0.0051 0.12%StHs 4.3491 0.0096 0.22%Nist610 4.3638 0.0052 0.12%StHs 4.3430 0.0088 0.20%Nist610 4.3608 0.0038 0.09%StHs 4.3312 0.0109 0.25%Nist610 4.3523 0.0060 0.14%StHs 4.3434 0.0116 0.27%Nist610 4.3543 0.0046 0.11%StHs 4.3399 0.0094 0.22%Nist610 4.3542 0.0048 0.11%StHs 4.3054 0.0119 0.28%Nist610 4.3399 0.0066 0.15%StHs 4.3250 0.0103 0.24%Nist610 4.3332 0.0052 0.12%StHs 4.3159 0.0096 0.22%Nist610 4.3237 0.0050 0.11%StHs 4.3230 0.0084 0.20%Nist610 4.3389 0.0044 0.10%

StHs6/80= 12 ppm BNist 610 = 350 ppm B

δ11B = -4.3 ± 2.4‰

Summary of resultsSummary of results

-15

-10

-5

0

5

10

15

-15 -5 5 15δ11B (‰) measured

δ11B

(‰

)re

fere

nce

B4 (tourmaline)B = 31400 ppm

StHs6/80 (glass)B = 11 ppm

GOR128-G (glass)B = 23 ppm

GOR132-G (glass)B = 18 ppm

error bars are 2σ

Results on Mt. Etna ashesResults on Mt. Etna ashes

Spot size 60 µmNist 610 external standard

Average δ11B = -8.0 ± 1.9 ‰

May October December

Other possible applicationsOther possible applications

• High precision U-Pb zircon dating• Li, Hf, Pb, Sr isotopes on geological samples

Provided that suitable standards for in-situ analyses are available

ConclusionsConclusionsLaser Ablation microprobeLaser Ablation microprobe

(266/213/193 nm)(266/213/193 nm)

MCMC--ICPMSICPMS

(LA)

HRHR--ICPMSICPMSMulti element(ppb level LOD)

&low precision isotope

determinations(Pb-geochronology)

Ion counters(ppm level determinations) (100s ppm determinations)

Faraday

High precision isotope determinations