An Introduction to ICP-MSAn Introduction to ICP-MS

PerkinElmer InstrumentsPerkinElmer Instruments

710 Bridgeport Avenue710 Bridgeport Avenue

Shelton, CT 06848Shelton, CT 06848

203-944-2481203-944-2481

Agenda of the courseAgenda of the course

10.00 --- 10.3010.00 --- 10.30 ICPMS- Introduction & Benefits ICPMS- Introduction & Benefits 10.30 --- 1.0010.30 --- 1.00 InstrumentationInstrumentation 1.00 --- 2.001.00 --- 2.00 LunchLunch 2.00 --- 2.30 2.00 --- 2.30 Interferences & how to overcome itInterferences & how to overcome it 2.30 --- 3.002.30 --- 3.00 Maintenance procedures Maintenance procedures 3.00 --- 3.153.00 --- 3.15 Tea BreakTea Break 3.15 --- 5.00 3.15 --- 5.00 Elan s/w Elan s/w 5.00 --- 5.305.00 --- 5.30 Q-A & FeedbackQ-A & Feedback

The ELAN DRC IIThe ELAN DRC II

What Is ICP-MS?What Is ICP-MS?

A metal detectorA metal detector

A technique used to measure metalsA technique used to measure metals• Capable of measuring ppt (ng/L) to ppm (mg/L) levelsCapable of measuring ppt (ng/L) to ppm (mg/L) levels

How it’s doneHow it’s done• Sample introduced into an Inductively Coupled Plasma (ICP)Sample introduced into an Inductively Coupled Plasma (ICP)• Ions are formed in the plasmaIons are formed in the plasma• Ions are sorted by massIons are sorted by mass• Ions are detectedIons are detected

Benefit of ICPMS over other techniquesBenefit of ICPMS over other techniques

1) Speed1) Speed

2) Good Detection limit –detection limit upto PPT level for most 2) Good Detection limit –detection limit upto PPT level for most elementselements

3)Can handle complex samples3)Can handle complex samples

4) Solid sampling possible with help of Laser ablation 4) Solid sampling possible with help of Laser ablation accessoryaccessory

5) Can detect each isotope of all elements giving possibility to 5) Can detect each isotope of all elements giving possibility to carry out isotope dilution & isotope ratiocarry out isotope dilution & isotope ratio

Elements ICPMS measure with detection limitsElements ICPMS measure with detection limits

ELAN family specificationsELAN family specifications

• DRC-e better than 9000…DRC-e better than 9000…» Same low background, slightly less sensitive than DRC IISame low background, slightly less sensitive than DRC II

ELAN 9000ELAN 9000 ELAN DRC-eELAN DRC-e ELAN DRC IIELAN DRC II

Detection Detection LimitsLimits

(ng/L)(ng/L)

99Be < 9Be < 95959Co < 2Co < 2

115115In < 0.5In < 0.5238238U < 0.5U < 0.5

99Be < 9Be < 95959Co < 1Co < 1

8080Se < 10 Se < 10 DRCDRC115115In < 0.5In < 0.5238238U < 0.5U < 0.5

99Be < 6Be < 64040Ca < 2.0 Ca < 2.0 DRCDRC5656Fe < 0.7 Fe < 0.7 DRCDRC

5959Co < 1Co < 1115115In < 0.2In < 0.2238238U < 0.2U < 0.2

SensitivitySensitivity

Mcps/ppmMcps/ppm

2424Mg > 10Mg > 10115115In > 40In > 40238238U > 30U > 30

2424Mg > 5Mg > 5115115In > 25In > 25238238U > 20U > 20

2424Mg > 8Mg > 85656Fe > 40 Fe > 40 DRCDRC

115115In > 40In > 40238238U > 30U > 30

CeOCeO++/Ce/Ce++ < 3%< 3%

BaBa2+2+/Ba/Ba++ < 3%< 3%

BackgroundBackground Mass 220 < 5 (sd)Mass 220 < 5 (sd) Mass 220<2cpsMass 220<2cps Mass 220<2cpsMass 220<2cps

StabilityStability < 4% over 4 hours< 4% over 4 hours

Note: DRC-e values are preliminary target mfg. Specifications not Note: DRC-e values are preliminary target mfg. Specifications not final at this timefinal at this time

Note: DRC-e values are preliminary target mfg. Specifications not Note: DRC-e values are preliminary target mfg. Specifications not final at this timefinal at this time

Components of Components of EveryEvery ICP-MS SystemICP-MS System

Sample introduction systemSample introduction system Ionization sourceIonization source InterfaceInterface Ion focusing systemIon focusing system Mass filterMass filter Ion detection systemIon detection system Control softwareControl software

ICP-MS - ICP-MS - Component DiagramComponent Diagram

ICP Torch

RF Supply

Sample

SprayChamber

MechPump

TurboPump

TurboPump

ICP-MS Computer and Control Electronics

Ion LensElectron Multiplier

Quadrupole Mass Filter

PlasmaSpectrometer

Interface

Sample Introduction SystemSample Introduction System

FunctionFunction • To get the sample into To get the sample into

the plasma the plasma

How it’s doneHow it’s done • Liquid is pumped into a Liquid is pumped into a

nebulizernebulizer

• An aerosol mist is An aerosol mist is created created

• The mist droplets are The mist droplets are separated by size in the separated by size in the spray chamberspray chamber

• Only the finest droplets Only the finest droplets are carried into the ICPare carried into the ICP

Ionization Source - Ionization Source - The Inductively Coupled Plasma (ICP)The Inductively Coupled Plasma (ICP)

FunctionFunction • To create ions from the To create ions from the

elements in the sampleelements in the sample

How it’s doneHow it’s done • The plasma temperature is The plasma temperature is

about 6000about 6000°°K K • The aerosol is dried The aerosol is dried • Positive Ions are created by Positive Ions are created by

stripping electrons from the stripping electrons from the aerosol particles which are aerosol particles which are directed into mass analyzer for directed into mass analyzer for quantification in ICPMS.quantification in ICPMS.

• It is generation, transportation, It is generation, transportation, & detection of significant nos of & detection of significant nos of these positively charged ions these positively charged ions that give ICPMS its that give ICPMS its characteristic ultratrace characteristic ultratrace detection capabilities.detection capabilities.

Ions Created Here

Mechanism of conversion of a droplet to + ion in ICPMechanism of conversion of a droplet to + ion in ICP

Different temperature zones in PlasmaDifferent temperature zones in Plasma

The InterfaceThe Interface

FunctionFunction • To transfer ions from the To transfer ions from the

ICP to the area for mass ICP to the area for mass separationseparation

– Atmospheric pressure to Atmospheric pressure to 1010-6-6 torr torr

How it’s done How it’s done • Ions are extracted from the Ions are extracted from the

plasma via differential plasma via differential pressurespressures

• Use cones and vacuum Use cones and vacuum pumpspumps

ICP

Sampler

Skimmer

10 -3 torr

10 -6 torr

Atmospheric Pressure

Interface Region and ConesInterface Region and Cones

Both Ni and Pt available Both Ni and Pt available

Large diameter orifices to Large diameter orifices to minimize clogging while minimize clogging while maintaining vacuummaintaining vacuum• Sampler - 1.1 mmSampler - 1.1 mm

• Skimmer - 0.9 mmSkimmer - 0.9 mm

Very easy maintenance: Very easy maintenance: removal, cleaning, removal, cleaning, reinstallation.reinstallation.

sampler coneskimmer cone

Ion Focusing System - Ion Focusing System - The Ion LensThe Ion Lens

FunctionFunction • To corral the ions after the To corral the ions after the

Interface and send them to Interface and send them to the mass filterthe mass filter

How it’s doneHow it’s done • An electric field focuses the An electric field focuses the

ions into the mass filter ions into the mass filter

• The electric field originates The electric field originates from an from an Ion LensIon Lens

• Ion LensIon Lens

– A metal cylinderA metal cylinder InterfaceIon OpticMass Filter

Mass Filter

Rf Only Filter

Differential Aperture

Shadow Stop

SamplerSkimmerCylinder

Lens

Ion Beam Focusing Ion Beam Focusing

Cylinder Lens Shadow Stop SkimmerAperture

AutoLens - Dynamic Lens OptimizationAutoLens - Dynamic Lens Optimization

0.2

0.4

0.6

0.8

1

1.2

1 3 5 7 9

Lens Voltage, V

Li

Co

Y

In

Pb

UNo

rmal

ized

Sig

nal

Ion LensIon Lens

One piece LensOne piece Lens

Voltage can be changed to Voltage can be changed to accommodate different accommodate different massesmasses

Shadow Stop blocks Shadow Stop blocks photons and non-ionized photons and non-ionized particles since they are particles since they are neutral & unaffected by neutral & unaffected by electrostatic field & pass electrostatic field & pass straight on the photon stop.straight on the photon stop.

Shadow Stop

Mass Filtering System - Mass Filtering System - The QuadrupoleThe Quadrupole

FunctionFunction • To separate one elements To separate one elements

(ions)(ions)

How it’s doneHow it’s done • Electro-magnetic fields of Electro-magnetic fields of

the quadrupole rods allow the quadrupole rods allow only oneonly one mass (m/z) to pass mass (m/z) to pass through it at a time through it at a time

• Many masses enter, Many masses enter, only only oneone makes it out makes it out

+

-

-

+

+

-

-

++

+ -

-

1 amu lighter 1 amu heavierSet mass

=> Driven into rods => Collide with rodsTransit successfully

Mass Filtering - Mass Filtering - How a Quadrupole WorksHow a Quadrupole Works

Ion Detection -Ion Detection - The Electron MultiplierThe Electron Multiplier

FunctionFunction • To count the number of ions To count the number of ions

leaving the mass filter.leaving the mass filter.

How it’s doneHow it’s done • Ions leaving the quadrupole Ions leaving the quadrupole

collide with the detectorcollide with the detector

• A cascade of electrons results A cascade of electrons results which can be measured by which can be measured by the electronics.the electronics.

Operates SimultaneouslyOperates Simultaneously • InIn Pulse Pulse and and AnalogAnalog modes modes

for increased dynamic rangefor increased dynamic range

• Measures low and high Measures low and high concentrations togetherconcentrations together

Ions In

Pulse Signal Out

AnalogSignal Out

Interferences in ICP-MSInterferences in ICP-MS

SpectralSpectral• Elemental-IsobaricElemental-Isobaric• Molecular-PolyatomicMolecular-Polyatomic

PhysicalPhysical MatrixMatrix

ICP-MS Spectral InterferencesICP-MS Spectral Interferences

Some common anions can form interferences which adversely Some common anions can form interferences which adversely effect detection limitseffect detection limits

InterferenceInterference AnalyteAnalyte4040ArAr 4040CaCa4040ArAr1616O, O, 4040CaCa1616OO 5656FeFe4040ArAr1212CC , , 3535ClCl1616OO11HH 5252CrCr 4040ArAr1313CC , , 4040ArAr1212CC 1 1HH 5353CrCr3535ClCl4040Ar, Ar, 3535ClCl4040CaCa 7575AsAs 1515NN1616OO, , 1414NN1616OO11HH 3131PP 4444CaCa1616OO 6060NiNi

3535ClCl1616OO 5151VV4040ArAr4040ArAr 8080SeSe

Ways to overcome spectral interferenceWays to overcome spectral interference

1)Removal of matrix & analyte preconcentration1)Removal of matrix & analyte preconcentration 2) Mathematical correction2) Mathematical correction 3)Cold Plasma technology3)Cold Plasma technology 4)Reaction Cell-DRC technology4)Reaction Cell-DRC technology 5)High resolution mass analyzer—Magnetic sector5)High resolution mass analyzer—Magnetic sector 6) Use of alternate mass number6) Use of alternate mass number

What is the ELAN DRC ?What is the ELAN DRC ?

ELAN ICP-MS system with a quadrupole located between lens and analytical quadrupole (mass analyzer)

Dynamic Reaction Cell can be pressurized with a reaction gas

– Interferences (e.g. ArCl+, ArC+) eliminated by reactions with a reaction gas

Dynamic Bandpass Tuning

- Actively controls the mass bandpass

inside the DRC

- Controls interference reduction

chemistry

- New interferences cannot form

ICP-MS with a Dynamic Reaction CellICP-MS with a Dynamic Reaction Cell

Cones

Lens

Reaction Cell QuadMass Analyzer Quad

Detector

Example of a Reaction Inside the DRC

Removal of 40Ar35Cl from 75As

++++

++++

++

++++

++

Gas InletGas Inlet

AnalyzerAnalyzerQuadrupoleQuadrupole

++

DRC DRC QuadrupoleQuadrupole

++ ++ ++ ++ ++++

++

40Ar35Cl

75As

Gas (H2)

75As

Ion-Molecule Reactions and Collisions

++++

++++

For Ultra-trace ICP-MS Analyses of Cr, V, As, For Ultra-trace ICP-MS Analyses of Cr, V, As, and Se in Biochemical Matricesand Se in Biochemical Matrices

Analyte DRC Eliminates

• 52Cr 40Ar12C, 35Cl16OH, 36Ar16O

• 53Cr 40Ar12CH, 40Ar13C, 37Cl16O 36Ar17O

• 51V 35Cl16O

• 75As 40Ar35Cl

• 80Se 40Ar40Ar

Matrix interferenceMatrix interference

Suppression of signal due to matrix itself like in case Suppression of signal due to matrix itself like in case of organic samples the sample introduction of of organic samples the sample introduction of samples is affected due to viscosity of the samples.samples is affected due to viscosity of the samples.

Compensation for this interference is the use of Compensation for this interference is the use of internal standardization.internal standardization.

Space –Charge interferenceSpace –Charge interference

Defocusing of low mass analytes in presence of high Defocusing of low mass analytes in presence of high mass analytes ions.mass analytes ions.

Proper application of lens voltage helps in removing Proper application of lens voltage helps in removing the high mass analyte ions while steering low mass the high mass analyte ions while steering low mass ions towards the quadrapole.ions towards the quadrapole.

MaintenanceMaintenance

1) Aspirate 2%hno3 for 10-15 min after the analysis 1) Aspirate 2%hno3 for 10-15 min after the analysis is over.is over.

2)Check & replace if necessary pump tubing.2)Check & replace if necessary pump tubing. 3)Clean spray chamber, injector , torch.3)Clean spray chamber, injector , torch. 4)Replace load coil if required.4)Replace load coil if required. 5)Check & clean both cones in 1% hno3 in ultrasonic 5)Check & clean both cones in 1% hno3 in ultrasonic

bath.bath. 6) Clean or replace lens.6) Clean or replace lens. 7) change pump oil after 3-6 months.7) change pump oil after 3-6 months. 8) Replace Detector.8) Replace Detector.