Small peaks compared to literature

Applies to

Electrochemical detector

Summary

Experimental settings are copied from literature data but peaks are (much) smaller than expected.

Cause

1. Differences in detection parameters. Applying the same ECD potential does not guarantee the same effective cell potential if another reference electrode is used.
2. The working electrode area may differ: a larger area gives more signal (but also more noise).
3. A difference in cell geometry can give a different outcome.
4. Differences in chromatographic settings. For example, the pH of the mobile phase usually has a major effect on peak height.

Remedy

Method settings from literature may need further optimization. Always check the signal-to-noise ratio when using a bit different potential settings (test a few larger and smaller in 0.1 V steps).

Adapt the working potential in case the reference electrode is not the same type. A Pd type ref usually has a larger potential by itself, compared to a AgCl salt bridge ref. For example, under acidic mobile phase conditions the applied potential in the ECD of 800 mV vs Ag/AgCl is the same as applying 560 mV vs HyREF.