2. Electrochemical Detection in HPLC 1

3. ALEXYS™ - HPLC/ECD  Applications  Neuroscience  Pharma  Clinical analysis  Food & Beverages  Environmental 2

4. 3 Why ECD?  extremely sensitive  highly selective

5. 4 Principle of HPLC/ECD  electrochemical reaction detector  potential (E) is driving force

6. 5 Electrochemical reaction ΔEΔE diffusionelectron transfer reaction

7.  Facilitates the EC reaction 6 Role of electrode potential E 0 20 40 60 80 100 040080012001600 E (mV) Signal (%) no reaction oxidation occurs A  B

8. Working range potential E  E working range determined by mobile phase 7

9. 8 Peak height vs. concentration  UV  Beer’s law E =  d C  ECD  Cottrell equation i lim = 1.47 n F (F m ) 1/3 (DA/b) 2/3 C A= WE area A b = spacer thickness C = concentration i lim = diffusion limited current measured (peak height) peak height (E) vs concentration (C) peak height (I lim ) vs concentration (C)

10. 9 Peak height vs. concentration  UV  Beer’s law E =  d C  ECD  Cottrell equation i lim = f (A/b) 2/3 C A= WE area A b = spacer thickness C = concentration i lim = peak height as simple as abc…

11. Electroactive Groups 10

12. Application areas… HPLC/ECD NeurosciencePharmaceutics Food Beverages Environment Polyphenols Clinical Analysis Vitamins 11 www.myAntec.com

13. 12 Summary Electrochemical Detection for HPLC  Potential driven  Selective  Sensitive Thank you!