Novel Applications of LA-ICP-MS - cigs.unimo.it 2 Overview What is Laser Ablation? Why use Laser...
Transcript of Novel Applications of LA-ICP-MS - cigs.unimo.it 2 Overview What is Laser Ablation? Why use Laser...
Dr Ciaran O‟ConnorLaser Ablation Sales Manager
Electro Scientific Industries Europe Ltd.
New Wave Research Division
University of Modena
29th May 2009
Novel Applicationsof LA-ICP-MS
www.new-wave.com
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Overview
What is Laser Ablation?
Why use Laser Ablation?
Which Wavelength?
Current solutions
Some Novel Applications
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What is Laser Ablation?
Laser Ablation is a solid sampling technique for use with:
– Inductively coupled plasma mass spectrometry (ICP-MS)
– Can also be used with Inductively coupled plasma optical emission spectroscopy (ICPOES)
A laser is used to generate a fine aerosol of sample particulate
A carrier gas (He) is used to transport the particles to the ICP
Particles are vaporised and ionised within the plasma
Ions are then tranported via electronic or magnetic lenses to a detector where they are counted.
Can be used on any solid sample!
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What is Laser Ablation?
He in ICP-MS
Hit a sample surface with a high irradiance beam (1µm to 1mm diameter)
Laser “couples” with the sample surface and creates a cloud of particulates
Transported to the ICP-MS for detection via a He/Ar carrier stream
Ablation Cell
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What is Laser Ablation?
Short-pulse laser ablation is
characterised by a plume of energised
particles (visible to the naked eye)
Careful selection of resonator and
homogenising optics gives a flat beam
profile capable of depth profiling
Ablation made on
silicate glass using
UP193SS
Expanding plume of
ablated material
following ablation
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Why use Laser Ablation?
Samples can be difficult to digest PGE metals (Pt, Ir, Rh, Os, Pd) Loss of “volatiles” during digestion Plastics analysis for RoHS (e.g. Hg in PEEK)
Quick and efficient sample introduction Easy route from solid to ICP No need for dilution (no loss of sensitivity) Minimising potential for contamination from sample handling
High spatial resolution Spot size as low as 1 µm Ideal for „spatial chemistry‟, e.g. zonation in minerals
Can also do bulk analysis Breaking through the 1mm barrier High sample quantity for excellent sensitivity Large area for best homogenisation
Reduced interferences Oxide interferences removed almost entirely (no water, no acid) Interferences mainly from matrix (polyatomic and isobaric)
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Is Wavelength Important For My Application?
266nm
UP266MACRO4th Harmonic Solid State Laser (Nd:YAG)
213nm
UP2135th Harmonic Solid State Laser (Nd:YAG)
193nm
UP193FX or UP193SSArF Excimer (Gas Phase) or “pseudo 6th” Harmonic Solid State (Nd:YAG)
What wavelengths are available?
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Is Wavelength Important For My Application?
193nm
213nm
266nm
NIST610 NIST612 NIST614 NIST616
<1%
<1%
<1%
<1%
<1%
<1%
<1%
<1%
13%
<1%
1.5%
24%
Percentage Transmittance
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266 nm 213 nm 193 nm
Tree Rings, Biological Tissues, Plastics, Soils, Air Filters, Metals
Ceramics, Teeth, Coral, Glasses, Otoliths
Fluid Inclusions, Gems, Thin
Sections, Geo samples
Is Wavelength Important For My Application?
Highly coloured or non-reflective opaque materials can be analysed
by all wavelengths (e.g. NIST610)
Pale materials required low-UV (<213nm)
Transparent and colourless materials require deep-UV (193nm)
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266 nm 213 nm 193 nm
Tree Rings, Biological Tissues, Plastics, Soils, Air Filters, Metals
Ceramics, Teeth, Coral, Glasses, Otoliths
Fluid Inclusions, Gems, Thin
Sections, Geo samples
Is Wavelength Important For My Application?
Lower wavelength leads to smaller “particle size distribution”
Improved transportation to ICP
More fully vaporised and ionised within ICP
Higher sensitivity
Less Fractionation
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What is Fractionation?
Fractionation is a change in the measured ratio of isotopes compared to their true ratio
Elemental fractionation is the change in measured relative concentration between different elements (e.g. Cu:Zn, U:Th)
Isotopic fractionation is the change in measured relative concentration between isotopes of the same element (e.g. 206Pb:208Pb)
Can be caused:
At the ablation process
During the transport process
Within the plasma
Fractionation is reduced when the particles size distribution (PSD) is lower
Use of lower wavelength (e.g. 193nm) reduces the PSD
Use of shorter pulse width reduces the PSD
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Laser Ablation – Family of Products
UP193SS
Deep UV in a bench-top solid state laser ablation system
UP193FX
Deep UV, short pulse excimer laser ablation system
UP213
General purpose UV in a bench-top solid state laser ablation system
UP MACRO
Large spot sizes at 266nm for bulk analysis, ultra-trace ICP-MS and ICP-OES
MIR10
Mid-infra-red laser heating and fusing
MicroMill
Precision milling tool for solid sample removalUP193FX
UP213
UP MACRO
MIR10
MicroMill
UP193SS
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Forensic
Glass FragmentPaintHairGun Shot ResidueInkIdentification of “fakes”
• Drugs• Microchips• Golf Balls
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9mm line width
No fracturing
Hair Analysis
Single strand of hair
(67µm wide, 25µm hole)
Forensic/Archaeological analysis of
hair
Toxicological studies
Isotope ratio studies
Exposure studies (occupational,
environmental, anti-terrorism etc.)
Can also do growth profiling (scan
along length of hair)
Also useful for fingernails or
biological tissue
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Fingerprinting of Paint – Depth Profiling
Strategy 1:
Ablation of a single spot on sample surface
Signal changes with depth
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Fingerprinting of Paint – Depth Profiling
Strategy 2:
Line scan on the side profile of paint
fragment
Steady state signal for each layer
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Glitter™ Standards window
Distribution of refractive index (RI) values
FBI database of flat glasses, 1964 to 1979
Distribution of refractive index (RI) values
FBI database of flat glasses, 1980 to 1997
There is less variability in the
optical and chemical characteristics
of modern glass
Traditional techniques such as
refractive index discrimination is
becoming less effective
Glass Analysis
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The major constituents of clear glass are typically very similar
Differences may be found at trace levels < 100 µg/g (< 0.01%)
Glass Analysis
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1831
620
621
A, B,& C
Sheet Glass
Flat Glass
Container Glass
Headlamps
Glass Analysis
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Atmospheric PM10 Particle Monitoring
Monitoring stations set up nationally
PM10 particles collected on quartz filters
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9mm line width
No fracturing
Analysis of particulate on
filter paper using 266nm
Nd:YAG
Able to resolve different
components of aerosol
Higher throughput than
solution analysis
Overcomes selectivity of
leaching methods
This study used to determine
Pb isotopic fingerprint of
PM10 particulate across the
UKCourtesy of Matt Horstwood, Steve Noble (NIGL, Keyworth) & Steve Smith (ERG, Kings College)
Atmospheric PM10 Particle Monitoring
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Soil Pellet Bulk Analysis
Element Mean Concentration (ppm) %RSD Certified Concentration (ppm)
Cr 186 1.5% 195
Cu 36.2 3.6% 46.4
Cd 11.8 7.8% 14.6
Hg 0.21 3.7% 0.25
Pb 45.1 10.7% 57.2
Pressed powders are known for their heterogeneity
Use a laser ablation system with a large beam diameter to average out heterogeneities
UP266MACRO – 610 micron x 610 micron
Scan the beam in a long line to ablate as large an area as possible
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Art Restoration
Must know the composition of materials before restoration Profiling with LA-ICP-MS gives direct information on layer composition
Fresco from roof of the Opera
House in Ljubljana, Slovenia
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Imaging of Elements and Proteins in Brain Tissue
24Mg
27Al
57Fe
63Cu66Zn β-Amyloid (153Eu)
Multiple line scans combined
to create elemental “maps”
By labelling proteins with antibodies that
have been tagged with Eu it is possible to
image a protein distribution by LA-ICP-MS
Hutchinson et al. Analytical Biochemistry 346 (2005)225-233
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LA-ICP-MS shows elemental
distributions in bone samples
Facilitates the study of
elements in the mineralization
zones of bone tissue
Resolution shows La occurs
only in mineralization zones
LA-ICP-MS used to examine
how metallo-drug compounds
interact with different types of
bone tissue to determine the
long term fate in the body
Acknowledgement
A.G. Cox1, J. Denton2 and C.W. McLeod1
1Centre for Analytical Sciences, University of Sheffield 2Laboratory Medicine Academic Group, University of Manchester
Profiling of La-drug Fate in Human Bone Tissue
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It is possible to differentiate
daily environmental events from
the initial larval stages to
adulthood
Each day a new layer of
biogenic carbonate is formed
Each layer is 4µm to 20µm wide
Within these layers is locked the
environmental chemistry of the
fish
Chronological Exposure to Elements in Fish Otoliths
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LA-ICP-MS effective for isotope ratio and elemental analysis at concentration ranges from < 1ppb
LA-ICP-OES effective for a concentration range between < 1ppm to %. It is particularly good at handling heavy plasma loading
The micro-destructive nature of laser ablation spectrometry preserves sample integrity
It is a direct, solid sampling technique
Laser Ablation Spectrometry is particular useful when analyzing samples that are difficult to digest or when there is very little of the sample available
Laser Ablation Spectrometry is FAST
Summary of Laser Ablation