Q-ICP-MS Mass Spectrometry: new challenges in food …€¦ · Q-ICP-MS Mass Spectrometry: new...
Transcript of Q-ICP-MS Mass Spectrometry: new challenges in food …€¦ · Q-ICP-MS Mass Spectrometry: new...
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Sandro Spezia, Enzo Trivellone
Modena 29 Maggio 2009
Q-ICP-MS Mass
Spectrometry: new
challenges in food safety and
environmental applications
2
XSERIES 2
XSERIES 2 CCT ED
Q ICP-MS
Q ICP-MS CCTED
ELEMENT 2
ELEMENT XR
High Resolution ICP-MS
Neptune
Multicollector ICP-MS
Se
lectivity
Thermo Fisher Bremen, Germany
Noise: 0.2 cpsNoise: 0.2 cps
Center of Excellence for ICP-MS
3
Introduction to the XSERIES 2 ICP-MS
Bench top quadrupole ICP-MS
Efficient Ar plasma ion source
Capable of detecting sub-pg mL-1
levels across most of the Periodic Table
Large dynamic range
• Can measure from sub-pg mL-1 to
mg mL-1 in a single run
Offers collision cell technology for
removing polyatomic interferences
Versatile technology, but ..........
• ....... limited to samples containing
< 0.2% (m/v) dissolved solids
(cones block above this level)
4
Interface cone options - what to use and when?
Xt interface
• Ni skimmer cone mounted in Cu-Ni adapter
• Gives low backgrounds for cone derived
analytes (Ni, elements thermally ionised from
the cones)
• Provides lower polyatomic interference levels
e.g. ArO+ and ArH+ on Fe and K than standard
(Xs) cones
• Provides ideal mass response for ppm
Na, K, Mg, Ca measurement with ppt
detection for trace heavy metals
• Offers good long term stability for
analysis, but shows significant signal
suppression for higher matrix samples
Na: blank to 300 ppm Cd: blank to 100 ppb
5
Application Specific Interfaces – Xs-
Extraction lens operated at
negative potential
• High sensitivity (>200kcps/ppb)
• Low background noise (<0.5 cps)
Highest signal to noise of any
quadrupole ICP-MS
Applications:
• Environmental (radionuclides),
isotope ratio, laser, GC/LC…
6
Example of Xs-: High Sensitivity U Determinations
ppb
7
Nebuliser options - what to use and when?
Glass concentric nebuliser
• standard design for the XSeries
• sample uptake rate ~ 0.8 mL min-1 (free aspirated
or pumped)
• good all-round performance (sensitive, stable),
but can block with higher salt samples
Burgener Miramist
• parallel path nebuliser design (liquid channel
alongside gas channel)
• sample uptake rate ~ 0.8 mL min-1 (pumped only)
• resistant to blocking; good for biological samples
Low flow concentric nebulisers (PFA)
• sample uptake rates down to 20 mL min-1 (free
aspirated mainly)
• susceptible to blocking
• best nebuliser for semicon analysis or low sample
volume work with filtered samples
8
XSERIES 2 Schematic
9
What is a CRC ?
A multipole enclosed in a cylinder
Controlled flow of gas into the cell
Interaction of ions with the gas
If reactive gas used, reactions occur
• All cells are reaction cells
Collision/Reaction Cell Technology
M+ and
XnYn‟+
M+ only out
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Basic Schematic of CRC ICP-MS
Gas 1 Gas 2
MFC 1 MFC 2
Detector
Quadrupole
Pre-
LensMultipole CellPost-
Lens
Rotary Pump
Plasma
Split-flow High-compression Turbo
11
(1) Collision-induced dissociation
Ar-Ar++ He Ar + Ar+ + He
Not thought to contribute much
12
(2) Chemical reaction
ArAr+ + H2 ArH+ + ArH
A major mechanism for removal
13
(3) Electron transfer
ArAr+ + H2 ArAr + H-H+
A major mechanism for removal
14
(4) Collisional retardation/differential transmission
* ArAr+ + He ArAr+ + * He
*
*
a.k.a kinetic energy discrimination
15
CCTED - Kinetic Energy Discrimination for Collisional or Reactive Chemistry
Collisional retardation / energy filtering
Collision/Reaction gas atom or
molecule
Analyte Ion M+ - Small collision
cross-section
Polyatomic Species e.g. ArX+ –
Larger collisional cross-section
Post-Cell Cell Pre-Cell
Decre
asin
g E
nerg
y
Energy
Barrier
From plasma
To quadrupole π Extraction Lens –
ensures that the energy of
the ions entering the cell are
ideal for collisional or
reactive chemistry
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Interface Flexibility
Only Thermo has made progress in this
critical ICP-MS aspect in the last 10
years!
Default Xt Interface
• Analyses heavy matrix samples without
drift
Optional Xs Interface
• Xs-
• For applications requiring higher sensitivity –
especially at higher masses
• Laser, LC, GC etc…
• Xs+
• New in the XSERIES 2
• Protective Ion Extraction
Ultimate BECs on low mass elements
Materials, semicon…
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NEW TOOLS: ESI – FAST
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NEW TOOLS: ESI – FAST
Increase of throughput
Decreasing of contamination
due to memory effects from
peristaltic pump tubing
On-line Internal standard
addition
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ICP-MS: high-end for elemental analysis
It can measure almost the whole periodic table in just about everything
It is not limited to elemental concentrations but offers high precision
isotope ratio determinations and, if coupled to separation devices,
species information
20
Elements or species ?
HO-As-OH
|
OH
O
||
H3C-As-OH
|
OH
O
||
H3C-As-CH3
|
OH
CH3
|
H3C-As+-CH2CO2-
|
CH3
CH3
|
H3C-As+-CH2CH2OH
|
CH3 Br-
BrO-
21
Definition - „the analytical activity of identifying and/or measuring the
quantities of one or more individual chemical species in a sample‟
IUPAC
That means – chemical species of an element are determined rather
than the total element concentration
Example – Tin species separated by gas chromatography (GC) and
detected by ICP-MS
What is Speciation Analysis?
Sn Sn
Sn
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Why do we need Speciation…?
Bioavailability
Environmental Fate
Mobility
Toxicity
Volatile Elemental
Species
Multi-Element/Isotope
High Sensitivity
High Selectivity
Process Control
Chemistry
Sn Sn
Sn
23
The chemical form can be very important…….
24
Elemental speciation data can reveal valuable information in addition to total element concentrations:
Speciation in Environmental, Food and Clinical Analysis
Environmental Fate
Mobility
Metabolic Processes
Bioavailability/toxicity
Reactivity
Industrial
Sources
Natural
SourcesHg0
Hg2+ MeHg+
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Growth of Speciation
26
HPLC-ICP-MS Applications
Element Species Matrices Scientific Sector
Cr Chromium III & VI Water, air particulates, cementEnvironment, industry, nutrition,
occ. exp.
As Organoarsenic compounds Fish, water, sediments, urine, hair Environment, nutrition, exposure
SeOrganoselenium Yeast, garlic, urine Nutrition, pharma, clinical
Hg Inorganic mercury, organomercury Fish, sediments, water, urine, blood Environment, Clinical
Sn Organotins Fish, sediments, water, plastics Environment, industry
Fe Iron II & III Bacteria, soils, water Environment, clinical, nutrition
Cu, Zn, Cd Phytochelatins, metallothioneins Plant tissues, brain & kidney tissue Agroindustry, clinical
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Speciation applications
Polypeptide sub-isoforms
Metallodrugs hydrolysis products
Metalloporphyrins and corrinoids
Organoselenium
Organoarsenic
Size-exclusion
Reversed-phaseAnion-exchage
Cation-exchageIon-pairing
Polysaccarides
Metallothioneine
Phytochelatins
Metalloenzymes
Transport proteins
Metallodrug-protein adducts
Polypeptide sub-isoforms
Redox states
Organoselenium
OrganoarsenicHPLC-ICP-MS
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CHEMICAL FORM LD50 (mg/kg)
Arsenite (As(III)) 14
Arsenate (As(V)) 20
Arsine (AsH3) 3
Monomethylarsonic acid (MMA) 700 - 1800
Dimethylarsinic acid (DMA) 700 - 2600
Arsenocholine > 10000
Arsenobetaine > 10000
Aspirin 1000 - 1600
Strychnine 16
LD50 rat: Lethal dose 50 (dose for which 50 % of a population is dead)
Arsenic Speciation – Why?
The toxicity of arsenic is strongly dependent on the chemical
form
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Arsenic Speciation – Why?
Arsenic is accumulated by marine biota
• Fish
• Shellfish
• Algae
Marine biota are able to transform arsenic species, creating
many arsenic containing species (over 30 As species have been
identified to date)
Upon consumption of marine biota, toxicity risk assessment is
needed and detoxification pathways can be elucidated
Presence of arsenic in fish and marine based products has also
disrupted international trade
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Speciation of As by Anion Exchange HPLC-ICP-MS
Optimization of HPLC parameters
Surveyor LC
ANION EXCHANGE: Hamilton PRP x-100, 250 x
4.6 mm, 5μm
• Gradient elution with 20-50 mM ammonium
carbonate buffer, pH 8.9
• Flow rate: 1mL/min, Inj. vol: 20 μL
1 ppb of each As standard
Check:Simple coupling
Plasma robustness
Organic solvents
Interference strategy
Data evaluation
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Speciation of As in Seafood by Anion Exchange HPLC-ICP-MS
Sample Prep Protocol
Fish samples – human consumption
• Filets sliced into small cubes
• Freeze-dried to remove moisture
• Ground to a fine powder with pestle and mortar
Extraction protocol
• 250mg fish sample extracted with 10mL H2O in ultrasonic bath at approx. 60°C
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As Speciation in Commercially Available Fish
Arsenic Containing Species (µg As/g) in Dried Fish
CRM Source AsB AsIII DMA
Unknown
A MMA AsV
DORM-2 (Dogfish
muscle) IRMM, Belgium 15,6 ± 1,04 - 0,2 ± 0,03 - - -
Sample Source
Red tuna North-East Atlantic 3.9 - 0.11 - - 0.13
Canned tuna Ecuador 3.42 - 0.12 - 0.08 -
Fillet of Trout Farmed, France 3.68 - - - - -
Freshwater Perch France 0.06 - - - - -
Ling North-East Atlantic 45.35 - - - - -
Alaskan Hake fillets* Pacific Ocean 12.78 - - - - -
Squid Heads* Indian Ocean 1.93 - - 0.02 - -
Arsenic Containing Species Recovery (%)
Sample Source AsB AsIII DMA
Unknown
A MMA AsV
Canned tuna Ecuador 97.6 115.8 104.8 - 114.1 129.1
Squid Heads* Indian Ocean 118.3 112.4 106.5 - 114.2 123.7
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Speciation of As in Urine by Anion Exchange HPLC-ICP-MS
Sample Y: Non-fish eater, non-occupationally exposed individual (smoker)
Sample X: Fish eater, non-occupationally exposed individual (non smoker)
34
Mercury Speciation – Why?
Industrial
Sources
Natural
SourcesVegetation
Atmospheric
Dispersion
Ocean
Natural sources:
• Volcanic activity
• Geothermal activity
Anthropogenic sources:
• Bactericide
• Manufacturing processes
• Fossil fuel combustion
Daily exposure:
• Fish consumption (MeHg+)
• Dental amalgams (Hg0)
• Vaccines – ‘Thimerosal’
Occupational exposure:
• Cinnabar (HgS) purification
• Gold mining
• Industrial processes
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Mercury Speciation - Toxicity
Toxicity of Hg is species dependant• Organomercurials are more easily absorbed and less readily eliminated than
inorganic Hg
Mobility and reactivity
• highly soluble in lipids
• transfers easily into blood
• crosses cellular membranes, blood-brain barrier
• pro-oxidant
• high affinity for free sulfhydryl groups and Se
Neurotoxin
• impairs mental and neurological function
• sensory and motor deficits
• also compromises hormone metabolism and inhibits protein and RNA synthesisGroups at risk:
Pregnant, nursing women, women of childbearing age and young children are in the highest group at risk because of the high sensitivity of foetus and child brain in development
36
Mercury Speciation for Risk Assessment
Provisional Tolerable Weekly Intakes
• Set by international scientific committees based on
threshold values for the effects on the
neurodevelopment of children
• 0.7 µg/kg body weight/week (NRC, 2000)
• 1.6 µg/kg body weight/week (JECFA, 2003)
International fish consumption
recommendations:
• EPA – pregnant women should limit consumption of
marine food to 6 ounces/week
• FDA – pregnant women should avoid consumption
of shark and swordfish
• EFSA – pregnant women should limit consumption
to 2 portions of fish/week, avoid swordfish and tuna
Amplification factor in food
chain means larger
predatory fish contain
higher levels of MeHg+
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High Mercury Levels Are Found in Tuna Sushi
“Tuna sushi is a popular item
in New York but may be risky.”
By MARIAN BURROS
Published: January 23, 2008
“Recent laboratory tests found so much mercury in tuna
sushi from 20 Manhattan stores and restaurants that at
most of them, a regular diet of six pieces a week would
exceed the levels considered acceptable by the
Environmental Protection Agency. “
38
Speciation of Mercury by RP HPLC-ICP-MS
HPLC column: Hypersil GOLD
(150 x 4.6 mm, 5µm)
Isocratic elution:
60 mM ammonium acetate, 5%
methanol, 0.01% 2-
mercaptoethanol
Flow rate: 1.5 mL/min
Inj. vol: 100 μL
HPLC parametersRun time 10 min
Sample
throughput
120/day
BEC 0.007 ng/g
LOD 0.05 ng/g
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Speciation of Hg in Fish (DORM-2) and Urine
Urine (plus spike)
DORM-2 (plus spike)
Extraction:
Analytical methodology (3 min.)
+ 5 mL TMAH
Microwave 2 min 40W
Fish sample prep
Urine sample prep
Analytical methodology (0 min.)
Method validation:
[MeHg+] = 4.27 ± 0.12 μg/g
(96% of certified value)
MeHg+
Hg2+
MeHg+
Hg2+
40
Thermo Scientific ICP-MS Speciation Packages
41
ELEMENT2/XSERIES 2 LC Coupling
42
ICP-MS for GC applications
Unique DUAL MODE sample introduction
• Three legged GC-ICP-MS torch
• Axial introduction of GC gas
• Aspirated solution introduced via 2nd leg
• GC transferline slots into holder in Faraday cage and is clamped into place
• Spray chamber is mounted via a specially configured adapter above the GC transfer line
43
Recent Development of GC Interface for ELEMENT 2
44
Advantages
Easy setup, tuning and performance testing with aqueous solution
Gas and solution analyses are possible without reconfiguring the
interface
Robust plasma conditions for GC-ICP-MS analysis due to wet plasma
On-line addition of aqueous internal standards
Entrained air from spray chamber burns up carbon of the solvent GC
injection, preventing carbon build up on the cones and improving long
term stability (there is no need for additional oxygen)
Sensitive multi-element capability
Speciation and total element analysis
•
45
GC-ICP-MS Applications
Elements Elemental Species Matrices Scientific Sector
Sn Organotins (TBT) Sediments, fish, water, plastics
Environment, nutrition, manufacturing,
packaging
Hg Organomercury (MeHg+)
Fish, sediments, water, blood,
petrochemicals
Environment, nutrition, exposure,
industry
SThiophene analogs and Hg
compounds Petrochemicals Petro Industry, environment
Br Flame retardants (PBDEs) Household dust, blood, milk, fat Clinical, industry, environment
Cl, P, S Pesticides Vegetables, fruit Agroindustry, environment
Pb Organolead Sediments, urban dust Environment
I Iodine species Thyroid, milk, seaweed Nutrition, clinical, environment
S, As, Sb, Ge,
Ga, Th,.. Organometallic gases Gas products Semiconductor industry, gas suppliers
C VOC Gas Industry, environment
46
Speciation of Mercury by GC-ICP-MS
Column Thermo Fisher Scientific Tr-5, 30 m x0.25mm ID, 25 μm
Injection mode PTV, splitless
Injection porttemperature
250 C with ramp to 400 C
Injection volume 1 µL
Carrier gas flow He @ 3 mL min-1
GC ovenparameters
50 C (1 min), ramp at 30 C/min to 300 C (1min)
Nebulizer andspray chamber
Concentric with impact bead (freeaspiration)
Nebulizer gas 0.35 L min-1
Additional gas Ar @ 600 mL min-1
Forward power 1400 W
47
GC-ICP-MS Speciation of Hg in Blood
Blank
NIST bovine blood
966 SRM
48
Speciation of Butlyltins – Why?
Sources of organo-Sn to the environment:
• PVC stabilisers ,fungicides, biocides, rodent repellents, wood preservatives, anti-foulants on ships and quays
Persistent compounds, resistant to degradation in water
Bio accumulate readily in fatty tissues
Broadly classified as endocrine disrupters & toxic to aquatic organisms at nano-molar concentrations
1970 1980 1990 2000
Occurrence of organotins in
open ocean waters and
accumulation in sea mammals
Ev
olu
tion
of
org
anot
inco
mp
ound
s co
nce
ntr
atio
ns in
co
asta
lwat
ers
(arb
itrar
yu
nits
PP
T)
Bio
log
ical
impa
cts
of
org
ano
tinco
mpo
unds
Analytical information
Increasing sensitivity and selectivity
CT/QFAAS
CGC/FPD or AEDCGC/ICP-MS
Time
Occurrence of organotins
in fresh water systems
and in household products
GFAAS
Oyster toxicity
and biological impacts in
coastal environments
Imposex phenomenom
in coastal and open seawater
ways
Ban of the use of TBT on
small vessel less than 25
meters
SnSn
Sn
49
Speciation of Butlyltins by GC-ICP-MS
Column Tr-5, 30 m x 0.25 mm i.d., df 0.25 µm
Injection mode Splitless
Injection port temperature 280 C
Injection volume 1 µL
Carrier gas flow He @ 1.5 mL min-1
Make up gas flow* Ar @ 400 mL min-1
Transfer line temperature 300 C isothermal
Initial temperature 60 C for 1 min
Ramp rate 50 C min-1
Final temperature 280 C for 1 min
Species LOD pg/g
MBT 3 (4 fg)
DBT 3 (4 fg)
TBT 1.7 (2.4 fg)
50
Conclusions
Flexible speciation packages for HPLC and GC applications
• Bi-directional communication in both speciation packages for automated speciation analysis
• Transient data processing integrated
• Unique dual mode sample introduction system for GC-ICP-MS
• Robust plasmas
Many chromatographic methodologies already developed and validated
Speciation is matrix dependent
• A method developed for fish may not necessarily work for blood, due to matrix components which
can disrupt extraction strategies or chromatographic elution
• The sample preparation is a major step in speciation analysis; the maximum of species should be
extracted from the tissue without changing the chemical form in the process
Low limits of detections (ppt range) are routinely achieved
• GC-ICP-MS tends to allow lower LODs but is not as flexible as HPLC
• Sector-Field ICP-MS delivers lower LODs compared to Quadropole ICP-MS
Several Legislations exist:
51
Speciation and Legislation
Element Matrix International Agency/Directive Legislation
Hg
Fish USEPA Criterion document 823-R-01-001 Criterion limit value of 0.3 mg/kg of MeHg+ (concentration of
MeHg+ in fish which is expected to be without appreciable risk to human health)
Water EU Water Framework Directive 2000/60/ECHg and its compounds listed as a priority hazardous
substances
Sn Water EU Water Framework Directive 2000/60/EC TBT listed as a priority hazardous substance
Cr
Automobiles EC directive 2000/53/EC Maximum of 2 g of Cr(VI) per end-of-life vehicle
Cement EC directive 2003/53/ECMaximum of 2 mg/kg Cr(VI) in cement or cement
preparations which will come into contact with skin
Workplace
AtmospheresUSEPA and ACGIH
Threshold Limit value of 0,05 mg soluble Cr(VI)/m-3 air and
0,01 mg insoluble Cr(VI)/m-3 air
Br Water EU Water Framework Directive 2000/60/ECPentabromodiphenyl ether listed as a priority hazardous
substance
Many governing bodies are now recognizing that the elemental species and not necessarily the total concentration of an element should be controlled
Legislation for elemental species focuses on the more toxic species
Future amendments to the Water Framework Directive in the EU will require maximal concentrations of 50 ppt for Hg compounds and 0.2 ppt for Tributyl tin in inland water systems
52
Traceability - REE
53
Tomato sauce – different countries
-0,01
0
0,01
0,02
0,03
0,04
0,05
0,06
µg
/g
Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Tb Tm Yb
# 1 # 2 # 3 # 4 # 5 # 6 # 7 # 8
54
Tomato sauce – REE analysis RRE of #1 vs. [# 2-8] average
0
0,01
0,02
0,03
0,04
0,05
0,06
µg
/g
Ce
Dy
* 10
Er*1
0
Eu
*10
Gd
Ho
*10
La
Lu
*10
Nd
Pr
Sm
Tb
*10
Tm
*10
Yb
# 1 Media # 2-8
55
LOD
139La
140C
e
141P
r
146N
d
147S
m
153E
u
157G
d
159T
b
163D
y
165H
o
166E
r
169T
m
172Y
b
175Lu
0.000
0.020
0.040
0.060
0.080
0.100
0.120
0.140
0.160
pp
tDETECTION LIMITS
LOD: < 0,2 ng/L
56
repeatability
0
5
10
15
20
139L
a
140C
e
141P
r
146N
d
147S
m
153E
u
157G
d
159T
b
163D
y
165H
o
166E
r
169T
m
172Y
b
175L
u
RSD % (10 replicates)
10 ppt 1 ppt 0,5 ppt
57
Forensic case: water contamination
0
5
10
15
20
139L
a
140C
e
141P
r
146N
d
147S
m
153E
u
157G
d
159T
b
163D
y
165H
o
166E
r
169T
m
172Y
b
175L
u
Home driver sample #1
0
10
20
30
40
50
139L
a
140C
e
141P
r
146N
d
147S
m
153E
u
157G
d
159T
b
163D
y
165H
o
166E
r
169T
m
172Y
b
175L
u
refinery plant
0
5
10
15
20
25
139L
a
140C
e
141P
r
146N
d
147S
m
153E
u
157G
d
159T
b
163D
y
165H
o
166E
r
169T
m
172Y
b
175L
u
tank truck
0
2
4
6
8
10
12
14
16
139L
a
140C
e
141P
r
146N
d
147S
m
153E
u
157G
d
159T
b
163D
y
165H
o
166E
r
169T
m
172Y
b
175L
uHome driver sample #2
58
APPLICAZIONI III: TRACCIABILITA’
139L
a
141P
r
147S
m
157G
d
163D
y
166E
r
172Y
b
S.ANNA
LAURA
S. FRANCESCOTAVINA
S. PELLEGRINOS. BERNARDO
LAURETANAGAUDIANELLO
0
10
20
30
40
50
60
70
80
PATTERN REE
S.ANNA LAURA S. FRANCESCO TAVINA
S. PELLEGRINO S. BERNARDO LAURETANA GAUDIANELLO