Electrochemical Detection in HPLC

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ALEXYS™ - HPLC/ECD

ApplicationsNeurosciencePharmaClinical analysisFood & BeveragesEnvironmental

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Why ECD?

extremely sensitivehighly selective

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Principle of HPLC/ECDelectrochemical reaction detectorpotential (E) is driving force

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Electrochemical reaction

ΔE

diffusion electron transfer reaction

Facilitates the EC reaction

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Role of electrode potential E

0

20

40

60

80

100

0 400 800 1200 1600

E (mV)

Sig

nal (

%)

no reaction

oxidation occurs

A B

Working range potential E

E working range determined by mobile phase

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Peak height vs. concentration

UV Beer’s law E = d C

ECD Cottrell equation ilim= 1.47 n F (Fm )1/3 (DA/b)2/3 C

A= WE area Ab = spacer thicknessC = concentrationilim= diffusion limited current measured (peak height)

peak height (E) vs concentration (C)

peak height (Ilim) vs concentration (C)

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Peak height vs. concentration

UV Beer’s law E = d C

ECD Cottrell equation ilim= f (A/b)2/3 C

A= WE area Ab = spacer thicknessC = concentrationilim= peak height

as simple as abc…

Electroactive Groups

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Application areas…

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www.myAntec.com

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Summary

Electrochemical Detection for HPLC

Potential drivenSelectiveSensitive

Thank you!