Electroanalysis with Carbon Paste–Based Electrodes, Sensors, and Detectors - Electroanalysis with Carbon Paste Electrodes - page 170

. 4.. Tables.8.15.through.8.28.with.all.the.remaining.organic.compounds.that.can.be.classiied.

as. biologically important compounds .( BIC .[58]).and.that.have.been.predominantly—but.
not.necessarily—determined.with.the.aid.of.various.CP-biosensors..For.technical.reasons,.
the.respective.table.had.to.be.divided.into.a.series.of.sub-tables.

Yet.before.going.to.the.individual.areas.of.practical.electroanalysis,.it.is.useful.to.comment.briely.on.
those.features.that.make.some.distinct.differences.in.practical.analysis.within.the.two.main.categories..
Thus,. under. the. optics. of. comparing. inorganic. analysis. versus. organic. analysis,. distinct. differences.
clearly. prevail. over. insigniicant. nuances.. Whereas. the. determination. of. inorganic. ions,. complexes,.
and. molecules. with. the. bare. (unmodiied). CPEs. is. rather. sporadic,. both. unmodiied. and. modiied.
CPEs.are.equally.applicable.in.organic.analysis..Unmodiied.CPEs.are.popular.mainly.in.situations.
where.a.hydrophobic.binder.acts.as.a.certain.type.of.modiier,.attracting.lipophilic.molecules.of.many.
organic.and.biological.compounds,.including.various.pharmaceuticals.or.drugs..Furthermore,.due.to.
a.very.close.behavior.of.numerous.organic.substances,.special.pre-separation.steps—by.using.HPLC,.
capillary.electrophoresis.(CE),.and.liquid-liquid.extraction.and.solid.phase.extraction.(LLE.and.SPE,.
resp.)—are.often.inevitable.prior.to.the.electrochemical.detection..Or,.in.contrast.to.inorganic.analysis,.
the.substances.of.organic.and.biological.origin.are.nearly.equally.analyzed.in.the.batch.arrangement.
and.in.lowing.streams—with.the.aid.of.electrochemical.detectors.in.low.injection.analysis,.liquid.chro-
matography,.capillary.electrophoresis,.and.electrochromatography;.i.e..in.arrangements.of.the.FIA-EC,.
LC-EC,.CE-EC,.and.ECC-EC.types..Also,.in.organic.electrochemistry,.practical.measurements.suffer.
more.from.the.undesirable.“poisoning”.of.the.CPE.surface.by.the.interfering.species.whose.voluminous.
molecules.may.totally.block.the.electrode.surface.[3,82]..Whereas.the.protocols.for.inorganic.analysis.
solve.these.problems.with.the.use.of.protective.membranes.or.via.electrode.regenerations.[55],.organic.
electroanalysis. requires. more. radical. solution,. total. isolation. of. the. target. analyte. from. the. original.
matrix.being.the.best..Finally,.organic.electroanalysis.often.does.not.require.extreme.performance.of.
detection.systems,.except.some.special.applications.in.environmental.monitoring.[2179,2180].
A.particular.case.is.then.pharmaceutical.and.clinical.analysis.with.CPEs.(recently.reviewed.in.
[158,2183]).where.the.aforementioned.problems.are.yet.more.pronounced.due.to.the.speciic.matrix.
of.biological.luids,.representing.commonly.analyzed.samples..Although.the.respective.procedures.
can. be. “relatively. simple”. with. respect. to. the. presence. of. interfering. species,. the. electroanalyti-
cal.performance.as.such.is.usually.quite.limited.due.to.the.disastrous.effect.of.major.matrix.con-
stituents..They.can.be.electroinactive,.but.their.excessive.content.is.the.source.of.serious.troubles,.
including.the.aforementioned.physical.blocking.of.the.electrode.surface..Due.to.this,.pharmaceuti-
cal.and.clinical.analysis.has.always.been.a.domain.of.a.very.narrow.spectrum.of.research.teams.
whose.scientiic.reports.are.relatively.well.recognizable.via.their.own.characteristic,.often.empirical.
or.even.routine.approaches.to.the.problematics..Last.but.not.least,.pharmaceutical.analysis.is.the.
only.area.where.unmodiied.CPEs.are.regularly.applied.to.date.
Nearly.the.same.can.be.stated.when.one.tries.to.specify.analysis.of.biologically.important.(active).
compounds..Of.course,.in.electroanalysis.with.CPEs,.there.are.different.proportions.and.a.wider.
impact. because. the. category. of. BIC. dominates. among. the. analytes. of. interest. for. lengthy. years..
Typical.is.also.the.vitality.of.various.specially.oriented.investigations.(e.g.,.electrochemistry.with/of.
DNA.[2184,2185],. in vivo .monitoring.[152,606],.or.the.research.on.electrochemical.immunosensors.
[2186,2187],.with.applicability.rather.in.biology,.toxicology,.and.medicine.than.in.electroanalysis.

8.1 DETERMINATION OF INORGANIC IONS, COMPLEX SPECIES,
AND MOLECULES
Inorganic. analysis. with. various. types. of. CPEs,. CMPEs. and. CP-biosensors. belongs. undoubtedly.
among.the.largest.areas.of.applications.of.carbon.pastes.in.the.electrochemistry..This.can.be.docu-
mented.in.a.myriad.of.publications.mentioned.earlier.and.within.this.section,.throughout.the.Tables.
8.1.through.8.11;.the.new.ones.being.numbered.[2188-2408].