Chemistry Reference
In-Depth Information
2
2
50 nA
Ru
III
100 nA
Rh
III
1
1
(A)
+1.0
+0.8
+0.6
+0.4
(B)
+1.0
+0.8
+0.6
+0.4
2
Ir
III
100 nA
Pt
IV
Os
IV
1
+0.9
+0.9
+0.3
E
[V] vs. Ag/AgCl
0
-0.3
(C)
FIGURE 8.8
Voltammetric.analysis.of.model.solutions.containing.Ru(III).(A),.Rh(III).(B),.and.a.mixture.of.
Pt(IV),.Ir(III),.and.Os(IV).(C).at.a.carbon.paste.electrode.modiied.with.surfactant.of.the.R
3
R′N
+
X
−
.type..(1).
Base-line.(supporting.electrolyte,.s.e.;.see.the.following).(2).5.×.10
−6
.M.Ru
III
.(A),.5.×.10
−6
.M.Rh
III
.(B),.and 5 ×.
10
−7
.M.Pt
IV
.+.4.×.10
−6
.Ir
III
.+.5.×.10
−8
.M.Os
IV
.(C)..
Experimental conditions
:.DPCSV;.accumulation.condi-
tions:.
E
ACC
.=.+0.9.V.vs..Ag/AgCl;.
t
ACC
.=.30.s,.
t
EQ
.=.15.s;.stripping.limits:.
E
INIT
.=.+0.9.V,.
E
FIN
.=.−0.3.V.vs. ref.,.
scan.rate,.10.mV.s
−1
;.pulse.height,.Δ
E
.=.−25.mV;.s.e.:.0.10.M.acetate.buffer.+.0.15.M.KCl.(pH.4.5).+.1 × 10
−5
.
M.Septonex
®
.(1-(ethoxycarbonyl)pentadecyl-trimethylammonium.bromide)..(Assembled.and.redrawn.from.
Švancara,.I..et.al.,.
Talanta
,.72,.512,.2007;.Galik.et.al.,.
Sensing in Electroanalysis
,.Eds..K. Vyt
ˇ
as,.K. Kaleher,.
University.of.Pardubice.Press,.Pardubice,.Czech.Republic,.pp..89-107,.2005.)
silica. [770]).. An. original. approach. is. the. adaptation. of. carbon. paste. as. the. sensing. element. of.
a. “lab-on-a-cable”. device. which. was. then. applied. to. decentralized. uranium. analysis. in. under-
groundwaters.[1379].
8.1.6 M
eTals
oF
The
F
ourTh
and
T
hird
g
roups
, M
eTals
oF
r
are
e
arThs
Several.elements.belonging.to.groups.III.and.IV.(Ti,.Zr,.Al,.Ga,.and.Sc).and.some.of.their.related.
lanthanides.or.actinides.(light.and.heavy.rare.earths).have.been.analyzed.using.CPEs.(see.second.
half.of.Table.8.9),.although.most.of.them.do.not.exhibit.attractive.electrochemical.features..This.
probably.contributes.to.explaining.why.a.relatively.wide.panel.of.methods.has.been.proposed.for.
their.determination.
Dealing.with.Ti,.Zr,.Al,.Ga,.or.Sc,.thanks.to.their.ability.to.form.stable.complexes.with.electro-
active.ligands.(e.g.,.Alizarin.derivatives),.a.strategy.based.on.indirect.voltammetric.detection.(i.e.,.
monitoring.changes.in.the.electrochemical.behavior.of.the.ligand.probe.upon.complexation.with.the.
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