Content uploaded by Ghada Bassioni
Author content
All content in this area was uploaded by Ghada Bassioni
Content may be subject to copyright.
1
ISSN: 1469-0667 © IM Publications LLP 2010
doi: 10.1255/ejms.xxx All rights reserved
EUROPEAN
JOURNAL
OF
MASS
SPECTROMETRY
The major components of cements are the tricalcium and
dicalcium silicates, alite and belite, respectively. Also present
in cements are tricalcium aluminate, tetracalcium aluminate
and calcium sulfate as well as numerous other minor phases.
Cements are compositionally heterogeneous on many length
scales; the anhydrous materials have the further complica-
tion of a large asymmetric particle size distribution and the
hydrated materials a complex porosity. At present, chemical
characterization methods almost entirely ignore such matters.
Therefore, it is of extreme importance to fi nd methods to further
distinguish between surface and bulk materials. Combining a
variety of techniques such as X-ray diffraction, small angle
X-ray scattering and X-ray absorption spectroscopy could
bring rich pickings in cement science, as a characterization
on several length scales and involving both amorphous and
crystalline components.
An interesting study conducted by Tsivilis and Kakali1
showed that admixtures of the raw material have a great
impact on phase-transformation processes of inorganic mate-
rials during the manufacture of cement clinker. Since the
greater part of alite is crystallized from the melt and alumi-
nates and aluminoferrites are crystallized when the liquid
Tracking traces of transition metals present
in concrete mixtures by inductively-coupled
plasma mass spectrometry studies
Ghada Bassioni,a,†,* Avin E. Pillay,a Mirella El Kadi,a Fadi Fegali,b Sai Cheong Foka and Sasi Stephena
aThe Petroleum Institute, PO Box 2533, Abu Dhabi, United Arab Emirates. E-mail: gbassioni@pi.ac.ae
bAl Husam Group, PO Box 2431, Abu Dhabi, United Arab Emirates
Transition metals can have a signifi cant impact in research related to the dosage optimization of superplasticizers. It is known that
the presence of transition metals can infl uence such doses, and the application of a contemporary instrumental method to obtain
the profi les of subsisting transition elements in concrete mixtures would be useful. In this work, inductively-coupled plasma mass
spectrometry (ICP-MS) is investigated as a possible tool to track traces of transition metals in concrete mixtures. Depth profi ling using
ICP-MS on proofed and unproofed concrete shows the presence of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn at trace intensities in the bulk of
the samples under investigation. The study demonstrates that the transition metals present in the concrete sample are largely a part of
the cement composition and, to a minor degree, a result of exposure to the seawater after curing. The coated concrete samples have a
metal distribution pattern similar to the uncoated samples, but slight differences in intensit y bear testimony to the very low levels that
originate from the exposure to seawater. While X-r ay diffraction fails to detect these traces of metals, ICP-MS is successful in detecting
ultra-trace intensities to parts per trillion. This method is not only a useful application to track traces of transition metals in concrete,
but also provides information to estimate the pore size distribution in a given sample by very simple means.
Keywords: transition metals, depth profi ling, laser ablation, ICP-MS
Introduction
G. Bassioni et al., Eur. J. Mass Spectrom. 16, xxx–xxx (2010)
Received: 5 October 2010
■
Revised: 25 November 2010
■
Accepted: 25 November 2010
■
Publication: 2010
†G. Bassioni is on leave from the Faculty of Engineering,
Ain Shams University, Cairo, Egypt
2 Tracking Traces of Transition Metals Present in Concrete Mixtures
phase solidifi es, the presence of admixtures cannot but affect
the crystallization conditions and, hence, the microstructure
of clinker. Therefore, the correlation to cement hydration is of
particular interest in order to be able to optimize operational
conditions.2,3
Traditionally, cement chemistry depends greatly on the
information provided by elemental analysis. Transition
elements, due to their distinguishing nature, such as ionic
radius, electric charge etc. seem to affect some of the physico-
chemical properties of the clinker. Mo and W, which are the
most acidic elements of those studied previously,1 cause a
viscosity decrease and, therefore, an increase in the diffusion
velocity of solids through the melt. As a result, bigger crystals
of alite are formed. Furthermore, transition metals have been
investigated by Scheidegger et al.4 in relation to studies of Co
incorporation into C–S–H and a further study deals with the
incorporation of Ni in cement systems.5
Although the use of inductively-coupled plasma mass spec-
trometry (ICP-MS) has been reported in a limited use to inves-
tigate the amount of lanthanides present in cements to prove
fl uorescence,6 we report here, for the fi rst time, its use as a tool
to track trace amounts of transition metals by depth profi ling.
We have successfully shown that tracking chloride and metal
diffusion in proofed and unproofed concrete,7 as well as trace
toxic elements,8 is possible by ICP-MS. Our work demon-
strates that systematic depth profi ling in concrete samples
can provide information on the distribution of these metals in
concrete and on pores present along the path towards the core
of the sample.
Experimental
Sample preparation
The samples under investigation are ordinary Portland
cement (CEM I), manufactured by the Ras Al Khaimah
cement plant in the United Arab Emirates. The chemical
composition of the cement listed in Table 1 is elaborated
by X-ray diffraction (XRD) measurements using a Bruker
AXS D8 Advance diffractometer. The qualitative analysis is
performed by EVA software while the quantitative phase
determination is carried out by RIETVELD analysis using
the TOPAS software (Bruker AXS). The concrete mix prepa-
ration is based on the British Method Design (BRE 106).
The compressive strengths of the concrete mixture are
20 N mm−2 and 40 N mm−2 with densities of 2409 kg m−3 and
2440 kg m−3, respectively.
A water to cement (w/c) ratio of 0.54 is used for grade 20 and
0.41 for grade 40 cement samples, while an aggregate/cement
ratio of 5.98 is used for the former and 4.68 is used for the
latter. The percentage of fi ne aggregates is 53% and 52% for
grade 20 and grade 40 cements, respectively. The maximum
aggregate size is 10 nm.
The concrete mixtures are poured into cubic molds of
50 mm × 150 mm × 150 mm in dimension. After curing, the
cubes are coated with a polyethylene fi lm and the effect of
the coating is further investigated. Laser experiments are
conducted on coated and uncoated samples.
The effect of transition metal presence on cement workability
is investigated using two different types of super plasticizers,
SP1 and SP2. A 0.1–0.5% concentration of superplasticizer (by
weight of cement) is used in this investigation following an API
RP 13I mixing rule. The rheology is studied by means of a mini-
slump test, in which the w/c ratio given above provides a fl ow
value of 18 ± 0.5 cm without the addition of superplasticizer.
ICP-MS laser ablation technology
The samples are investigated with a Perkin Elmer SCIEX DRC-e
ICP-MS (Connecticut, USA) fi tted with a New Wave UP-213
laser ablation system. The technique is highly sensitive and
can attain a limit of detection of 10−6 mg kg−1 (parts per trillion)
for transition metals. The concrete cored discs are placed into
a special sample holder with dimensions 5 cm × cm 5 cm. The
samples are irradiated with a 213 nm laser without prior treat-
ment at different points on the sample. The level of the beam
energy is 70% with a fluence of about 12 J cm−2 and beam
diameter of 100 μm. The laser is programmed to: (1) ablate a
depth of 5 μm at each point; (2) repeatedly scan the surface;
and (3) record measurements after each ablation to a total
depth of 50 μm.
This technique is largely semi-quantitative and is a reliable
tool when it comes to comparison of samples under the same
operational conditions. Appropriate spectra are produced to
observe variations in characteristic elemental profi les spatially
and with penetration depth.
Results and discussion
Analysis by X-ray diffraction
The diffractogram corresponding to the used clinker is shown
in Figure 1 and the Rietveld analysis is presented in Table 1,
where all the typical Portland cement clinker phases, such as
C3S, C2S and C3A among others, can be identifi ed.
Abundance of transition metals
The chemistry of cement, its hydration and mechanisms of
solidifi cation/stabilization (s/s) of toxic metals by cement-based
Clinker phase Percentage (%)
Alite, C3S53.15
Belite, b-C2S 4.23
C3A 4.63
Brownmillerite, Ca2(Al,Fe)2O510.97
Calcite, CaCO323.49
Periclase, MgO 0.42
Anhydrite, CaSO4 0.88
Arcanite, K2SO4 2.23
Table 1. Rietveld analysis of the cement CEM I under investigation.
G. Bassioni et al., Eur. J. Mass Spectrom. 16, xxx–xxx (2010) 3
systems and pozzolanic materials are signifi cantly controlled
by surface, near-surface and interfacial phenomena. The
adsorption conditions and the selectively strong affinity of
hazardous metals towards clay minerals, certain hydrated
metal oxides and oxyhydroxides, and cementitous substances
also play an important role in the s/s process for the immobi-
lization of contaminants.9
While ICP-MS has been extensively used in the detection of
transition metals in solution,10–12 to the best of our knowledge
we report here for the fi rst time the use of ICP-MS as a detec-
tion tool for transition metals at very low concentrations and in
a solid sample by depth profi ling.
Typical spectra depicting the profile of transition metals
concentration with depth appear in Figures 2–5 and supple-
mentary fi gures 1–4. It is shown that at certain depths, the
transition metal intensity changes sharply. This is attributed
to the presence of minor blockages that limit even distribu-
tion and create a diversion in the chemical composition of
the sample at a certain depth. These blockages constitute
conglomerates of gravel/sand/cement in certain proportions.
It has been reported that sand and stone sizes normally range
from 100 μm to 10 mm.13
The appearance of sporadic tall peaks in a spectrum
demonstrates the presence of “hotspots” which are sites in
the interior of the sample where the transition metal under
investigation accumulates. Bottlenecks caused by pores, voids
or cement admixtures can be collectively responsible for this
phenomenon.
Effective proofi ng on concrete prevents seawater migration
into the pores/voids present in the concrete mixture, as we have
reported previously.7,8 Transition metals present in the seawater
have been expected to play a signifi cant role in transition metal
concentration of the concrete samples. Nevertheless, depth
profiling using ICP-MS shows that only traces of vanadium
and zinc are found to accumulate after seawater exposure.
The remainder of the transition metals studied has similar
concentrations in the case of proofed and unproofed concrete.
Pore size distribution
It was previously shown that laboratory-mixed and fi eld-mixed
concretes exhibit dense areas or patches of hardened cement
paste which are sharply delineated from adjacent, highly
porous areas. Direct experimentation with long-continued
concrete mixing showed that this microstructural pattern
was not due to inadequate mixing. An experiment has been
conducted to determine whether this distinctive micro-
structure is associated with the fl occulation inherent in most
fresh concretes.14 In this study, the same fi nding is observed.
As can be seen from Figures 2–5 and Supplementary Figures
1–4 repeated parts which resemble void areas in the concrete
indicate the presence of pores. Grade 20 and 40 show clear
distributions of pores and/or cement admixtures.
Hardened concrete is a material with a pore-size distribution
range that extends down to the dimensions of molecules. As
a result of capillary depression of the vapor pressure of water,
signifi cant amounts of liquid water can exist in small concrete
pores, even when the external relative humidity falls below
100%. A good example of an obstructed path is shown in Figures
2 and 3, which represents a spectrum delineating an abrupt end
to the diffusion of the transition metals after a depth of about
25 μm. This is caused by the presence of different types of pores
in the concrete sample. A pore size of 10–10,000 nm is termed
a capillary pore while a pore size of 10–50 nm and <10 nm are
termed small pore and gel pore, respectively. Entrained air
bubbles or air voids have a size range from 50 μm to 10 mm.9
ICP-MS is therefore a useful tool to determine pore distribution
and their size by simple means.
Effect on the addition of superplasticizers
The properties of the cement matrix, especially its chemical
composition, have a major infl uence on the strength and dura-
bility of concrete. The brittle nature of the cement matrix and
the existence of a weak transition zone in the vicinity of aggre-
gates or reinforcement are among factors that attract signifi -
cant attention within the research community.
Figure 1. X-Ray diffractogram of the used cement.
4 Tracking Traces of Transition Metals Present in Concrete Mixtures
Figure 2. ICP-MS spectrogram showing Sc, Ti, V, Ni content in the unproofed sample of aggregate (C20).
G. Bassioni et al., Eur. J. Mass Spectrom. 16, xxx–xxx (2010) 5
Figure 3. ICP-MS spectrogram showing Cr, Mn, Fe, Zn content in the unproofed sample of aggregate (C20).
6 Tracking Traces of Transition Metals Present in Concrete Mixtures
Figure 4. ICP-MS spectrogram showing Sc, Ti, V, Ni content in the proofed sample of aggregate (C40).
G. Bassioni et al., Eur. J. Mass Spectrom. 16, xxx–xxx (2010) 7
Figure 5. ICP-MS spectrogram showing Cr, Mn, Fe, Zn content in the proofed sample of aggregate (C40).
8 Tracking Traces of Transition Metals Present in Concrete Mixtures
The characteristics of concrete or cementitious injection
grouts are infl uenced by the mass ratio of water to cement
materials used in the mixture. Reducing the proportion of
water increases the cement paste density. This results in a
higher paste quality. An increase in paste quality will yield
concrete with higher compressive and flexural strength,
lower permeability, increasing resistance to weathering and
improves the bonding of concrete and reinforcement, reduces
the volume change from drying and wetting and reduces
shrinkage cracking tendencies. Reducing the water content
in a mixture may result in a stiffer mixture, which reduces the
workability and increases potential placement problems.
Water reducers, retarders and superplasticizers are
admixtures for concrete which are added to reduce the
water content in a mixture or to slow the setting rate of the
concrete while retaining the flow properties of a concrete
mixture. Superplasticizers are soluble macromolecules that
are hundreds of times larger than a water molecule. The inter-
action mechanism of the superplasticizers is known to be
adsorption by the cement grain, which prevents agglomera-
tion by repulsion of the same charges and releases entrapped
water. The adsorption mechanism of superplasticizers is
partially different from that of a water reducer. The difference
relates to the compatibility between Portland cement and
superplasticizers. It is necessary to ensure that the super-
plasticizers do not become permanently fixed in a cement
particle, which would cause a reduction in concrete worka-
bility. The mechanisms of superplasticizer–cement interaction
have previously been reviewed.15,16 The role of calcium cations
as charge neutralizers by providing a positively charged site for
sorption of negatively charged polyelectrolytes was postulated.
This model can account for the retardation in hydration and the
rapid increase in negative zeta potential owing to interaction
of cement with polyelectrolytes with no hydrophobic tail. The
reactions decrease the amount of free calcium and affect
the hydration of cement temporarily. Sorption of additives on
cement is high and there are indications that desorption of
polyelectrolyte additives from hardened cement is very slow.
The distribution of a superplasticizer can be divided into three
portions: polymers in the pore water, adsorbed polymers and
incorporated polymers.
Typical superplasitizing formulas include carboxylic-type
acid.17 These have been investigated on complexation with
transition metals.18 It has been found that Cu(II) with salicylate
is considerably greater than the complex stability constant of
Cu(II) with aliphatic ligands and Fe is mobilized from basalt
considerably more than Al in the presence of citrate:19
citrate, oxic: P < Cu < Y < Fe < Mg < Zr = Rb < Si < Cr < V < Ba < A ■
< Ti
citrate, anoxic: Fe ~ P < Y < Mg < Si < Zr < Rb < Cr < Al < V < Ba <
■
Ti < Cu.
In comparison, Eick and colleagues20 reported the following
order of elements released from basalt (Duluth, Minnesota,
USA) with and without 0.002 mol L−1 or 0.02 mol L−1 citrate at
pH (7):
citrate, oxic: Mg ~ Fe < Si < Ca ~ Al.
■
In this study, typical commercial superplasticizers (SP1 and
SP2) are used as indicators for the effect of present transition
metals on the dosage necessary to obtain an increase in the
fl ow value and, consequently, on the workability of the cement
paste.
Figure 6 shows that with this cement under investigation
higher dosages than usual have to be used in order to obtain
satisfying results with cements of different sources, which
is in good agreement with previous studies.2 The sources of
this deviation can be understood if we note that the tendency
Figure 6. Correlation between the dosage of superplasticizer (SP1 and SP2) as a percentage by weight of cement (bwoc) and the fl ow
value, in centimeters.
G. Bassioni et al., Eur. J. Mass Spectrom. 16, xxx–xxx (2010) 9
of metal ions to complex with organic ligands correlates with
the tendency of the metals to hydrolyze.21 Thus, trends in
metal mobility can often be predicted. The best example of
this ordering is the observation that the tendency for divalent
metals to complex with organic ligands increases along the
Irving–Williams series: Mn2+ < Fe2+ < Co2+ < Ni2+ < Cu2+ < Zn2+ (for
example, Stone22). This sequence is generally only quoted
for Mn2+ through Zn2+ since the other first row transition
metals do not occur in the divalent state in natural terrestrial
environments.23
Aromatic carboxylic acids and citric acid increase the sorp-
tion of divalent transition metal ions on iron oxides at lower
pH (3–7). The increase is directly proportional to the strength
in complexation with the acid.24,25 No reference to studies on
the interaction or complexation between copper and poly-
carboxylate-type superplasticizers is found. As it is assumed
that polycarboxylic ester (ether) types of superplasticizer will
undergo hydrolysis and further degradation to carboxylic
acids, literature on the effects on binding of Cu with carboxylic
acids is surveyed. Under reducing conditions, Cu is likely to be
present in the form of Cu(I), which is more weakly hydrolyzed
than Cu(II). No complexation constants for Cu(I) with relevant
carboxylic acid are found in the literature. However, sorption of
Ni, Cu(II) and Pb on linear hydrosoluble poly(acrylic acids) has
been studied in 0.1–1.0 mol L−1 NaNO3 at pH 4–6,26–29 and on
cross-linked poly(acrylic acid).30 The order of increasing sorp-
tion is found to be Ni < Cu(II) < Pb. It has been reported that
the stability of Cu(II)–poly(acrylic) acid is greater than those of
acetic or glutaric acid Cu complexes.26
Conclusion
Trace transition metal analysis is of extreme importance to
optimize dosages of superplasticizers which improve the
workability of cement. ICP-MS has proven to be a useful tool
to determine the amount of trace transition metals present in
an easy, user-friendly way. It is found that in the presence of
transition metals, more superplasticizer is needed. ICP-MS
has shown the capability to give information on the pores
present in the cement matrix,and their size and distribution
in the bulk. Therefore, this study can be further explored for
shrinkage reducing agents used in the cement industry nowa-
days.
Acknowledgement
The authors wish to thank the Petroleum Institute for fi nancial
support of this work.
References
1. S. Tsivilis and G. Kakali, “A study on the grindability of
Portland cement clinker containing transition metal
oxide”, Cem. Conc. Res. 27, 673 (1997). doi: 10.1016/
S0008-8846(97)00050-1
2. G. Bassioni, “The infl uence of cement composition on
superplasticizers’ effi ciency”, Int. J. Eng. 4, 577 (2009).
3. Y. Al Wahedi, J. Awayyes and G. Bassioni,
“XXXXXXXXXX”, Adv. Cem. Res. (2010). in press.
4. A.M. Scheidegger, M. Vespa, D. Grolimund, E. Wieland,
M. Hrfouche, I. Bonhoure and R. Dahn, “The use of
(micro)-X-ray absorption spectroscopy in cement
research”, Waste Manage. 26, 699 (2006).
5. M. Vespa, R. Dähn, E. Gallucci, D. Grolimund, E. Wieland
and A.M. Scheidegger, “Micro-scale investigations of Ni
uptake by cement using a combination of scanning elec-
tron microscopy and synchrotron-based techniques”,
Env. Sci. Technol. 40, 7702 (2006).
6. S.P. Newman, S.J. Clifford, P.V. Coveney, V. Gupta, J.D.
Blanchard, F. Serafi n, D. Ben-Amotz and S. Diamond,
“Anomalous fl uorescence in near-infrared Raman spec-
troscopy of cementitious materials”, Cem. Conc. Res. 35,
1620 (2005). doi: 10.1016/ j.cemco nre s.2 004.10.001
7. A.E. Pillay, M. El Kadi, F. Fegali, S. Fok, G. Bassioni and
S. Stephen, “Tracking chloride and metal diffusion in
proofed and unproofed concrete matrices using ablative
laser technology (ICP-MS)”, Nat. Sci. 2, 809 (2010).
8. M. El Kadi, A.E. Pillay, F. Fegali, S. Fok, G. Bassioni and
S. Stephen, “Depth profi ling (ICP-MS) study of toxic
metal buildup in concrete matrices: Potential envi-
ronmental impact”, Sustainability 2, 3258 (2010). doi:
10.3390/su2103258
9. M. Yousuf, A. Mollah, R.K. Vempati, T.-C. Lin and D.L.
Cocke, “The interfacial chemistr y of solidifi cation/
stabilization of metals in cement and pozzolanic
material systems”, Waste Manage. 15, 137 (1995). doi:
10.1016/0956-053X(95)00013-P
10. N.G. Beck, R.P. Franks and K.W. Bruland, “Analysis for
Cd, Cu, Ni, Zn and Mn in estuarine water by inductively
coupled plasma mass spectrometry coupled with an
automated fl ow injection system”, Anal. Chim. Acta 455,
11 ( 200 2).
11. C.-Y. Huang, N.-M. Lee, S.-Y. Lin and C.-Y. Liu,
“Determination of trace metal ions in water samples
by on-line preconcentration and inductively coupled
plasma mass spectrometry”, Anal. Chim. Acta 466, 161
(2002). doi: 10.1016/0003-2670(93)80231-9.
12. H.-J. Yang, K.-S. Huang, S.-J. Jiang, C.-C. Wu and C.-H.
Chou, “Determination of trace metal ions in water sam-
ples by on-line preconcentration and inductively coupled
plasma mass spectrometry”, Anal. Chim. Acta 282, 437
(199 3).
13. S. Mounicou, J. Szpunar and R. Lobinski, “Inductively-
coupled plasma mass spectrometry in proteomics,
metabolomics and metallomics studies” Eur. J. Mass.
Spectrom. 16, 243 (2010). doi: 10.125 5/ejms.105 9
14. P. Mehta and P. Monteiro, “Concrete: Microstructure,
Properties, and Materials”, 3rd Edn. Ed by L.S. Hager.
McGraw-Hill, XXXXX, (2006).
10 Tracking Traces of Transition Metals Present in Concrete Mixtures
15. S. Diamond, “The patch microstructure in concrete:
the effect of superplasticizer”, Cem. Conc. Res. 36, 776
(2006).
16. M.Y.A. Mollah, W.J. Adams, R. Schennach and D.L.
Cocke, “A review of cement–superplasticizer interac-
tions and their models”, Adv. Cem. Res. 12, 153 (2000).
17. G. Bassioni, “A study towards ‘greener’ construc-
tion”, Appl. Energy (2010), in press. doi: 10.1016/j.apen-
ergy.2010.09.012
18. J. Plank and G. Bassioni, “Adsorption of carboxylate
anions on a CaCO3 surface”, Z. Naturforsch. B 62b, 1277
(2007).
19. G. Bassioni and J. Plank, “Untersuchungen zur kom-
petitiven Adsorption anorganischer Anionen am
Modellsystem Kalksteinmehl”, GDCh Monographie 36,
225 (2006).
20. A. Neaman, J. Chorover and S. Brantley, “Implications of
the evolution of organic acid moieties for basalt weath-
ering over geological time”, Am. J. Sci. 305, 147 (2005).
doi: 10.2475/ajs.305.2.147
21. M.J. Eick, P.R. Grossl, D.C. Golden, D.L. Sparks and D.W.
Ming, “Dissolution of a lunar basalt simulant as affected
by pH and organic anions”, Geoderma 74, 139 (1996).
22. B.J. Hernlem, L.M. Vane and G.D. Sayles, “Stability con-
stants for complexes of the siderophore desferrioxamine
B with selected heavy metal cations”, Inorg. Chim. Acta,
244, 179 (1996). doi: 10.1016/0020-1693(95)04780-8
23. A.T. Stone, “Reactions of extracellular organic ligands
with dissolved metal ions and mineral surfaces”, in
Geomicrobiology: Interactions Between Microbes and
Minerals: Reviews in Mineralogy, Volume 35, Ed by J.F.
Banfi eld and K.H. Nealson. Mineralogical Society of
America, Washington, DC, USA, p. 309 (1997).
24. C.P. Marshall and R.W. Fairbridge, Encyclopedia of
Geochemistry. Kluwer Academic Publishers, Dordrecht,
The Netherlands, 768 pp. (1999).
25. M.J. Angove, J.D. Wells and B.B. Johnson, “Adsorption of
cadmium(II) onto goethite and kaolinite in the presence
of benzene carboxylic acids”, Colloids Surf. A 146, 243
(1999). doi: 10.1016/S0927-7757(98)00799-7
26. H. Marcussen, P.E. Holm and H.C.B. Hansen, “Nickel
sorption to goethite and Na-montmorillonite in pres-
ence of citrate”. Oral presentation at 7th International
Conference on Biochemistr y of Trace Elements, Uppsala
Sweden 15–19 June (2003).
27. C. Morlay, Y. Cromer, Y. Mouginot and O. Vittori,
“Potentiometric study of Cu(II) and Ni(II) compl-
exation with two high molecular weight poly(acrylic
acids)”, Tal anta 45, 1177 (1998). doi: 10.1016/S0039-
9140(97)00229-4
28. C. Morlay, Y. Cromer, Y. Mouginot and O. Vittori,
“Potentiometric study of Cd(II) and Pb(II) complexation
with two high molecular weight poly(acrylic acids); com-
parison with Cu(II) and Ni(II)”, Talanta 48, 1159 (1999). doi:
10.1016/S0039-9140(98)00336-1
29. S. Perret, C. Morlay, Y. Cromer and O. Vittori,
“Polarographic study of the removal of cadmium(II) and
lead(II) from dilute aqueous solution by a synthetic fl oc-
culant. Comparison with copper(II) and nickel(II)”, Water
Res. 34, 3614 (2000). doi: 10.1016/S0043-1354(00)00112-3
30. C. Morlay, Y. Cromer, Y. Mouginot and O. Vittori, “The
removal of copper(II) and nickel(II) from dilute aque-
ous solution by a synthetic fl occulant: a polarographic
study of the complexation with a high molecular weight
poly(acrylic acid) for different pH values”, Water Res. 34,
455 (2000). doi: 10.1016/S0043-1354(99)00182-7
31. C. Morlay, Y. Cromer, Y. Mouginot and O. Vittori,
“Determination of the complexation properties of
a crosslinked poly(acrylic acid) gel with copper(II),
nickel(II), and lead(II) in dilute aqueous solution”, Can. J.
Chem. 79, 370 (2001). doi: 10.1139/cjc-79-4-370
Author Query
1. We have renumbered the references making 12a 12 and 12b 13 and renumbered the remaining references accordingly. I am
presuming that both 12a and 12b were included in the citation 10-12 on page 5 line 113/114 of your original manuscript. If they
should be cited elsewhere can you please let me know. Can you also check that we have renumbered the references correctly.
2. Can you please let me know the town and country of the Publisher in Reference 14
G. Bassioni et al., Eur. J. Mass Spectrom. 16, xxx–xxx (2010) 11
Supplementary material
Figure S1. ICP-MS spectrogram showing Sc, Ti, V, Ni content in the unproofed sample of aggregate (C40).
12 Tracking Traces of Transition Metals Present in Concrete Mixtures
Figure S2. ICP-MS spectrogram showing Cr, Mn, Fe, Zn content in the unproofed sample of aggregate (C40).
G. Bassioni et al., Eur. J. Mass Spectrom. 16, xxx–xxx (2010) 13
Figure S3. ICP-MS spectrogram showing Sc, Ti, V, Ni content in the proofed sample of aggregate (C20).
14 Tracking Traces of Transition Metals Present in Concrete Mixtures
Figure S4. ICP-MS spectrogram showing Cr, Mn, Fe, Zn content in the proofed sample of aggregate (C20).
