Select Page
Welcome to our Knowledge Base

How to improve my detection limit?

You are here:
< All Topics

Applies to

LC-EC system

Answer

The detection limit is the peak height that gives a significantly (at least 3 times) higher signal than the baseline noise. It is improved if the signal increases and/or the noise decreases. Signal and noise are not only determined by the detector but in fact by the settings and quality of the whole LC-EC system so no simple advice can be given. Improvement includes optimization of:

  1. Sample pre-treatment
  2. Flow rate and getting rid of pump pulsations
  3. LC parameters (mobile phase, column, injection volume, selectivity etc)
  4. Detector settings (range, potential etc.)
  5. Flow cell parameters (spacer, working electrode)
  6. Electronic noise suppression

Improving sensitivity in most cases goes hand in hand with improving detection selectivity. In many LC-EC analyses (blood, urine, CSF) interfering peaks (‘chemical noise’) in the chromatogram are the limiting factor. By a better sample pre-treatment this chemical noise can be suppressed. Flow rate fluctuations are a major noise source in LC-EC. Due to pump properties they have a regular pattern that can be calculated if the stroke volume is known. A pulse damper is a must in trace analysis.

For ALEXYS analyzers all this optimization has been done by Antec’s research lab. The result is ‘wrapped up’ in a system solution including guaranteed applications.

Was this article helpful?
0 out Of 5 Stars
5 Stars 0%
4 Stars 0%
3 Stars 0%
2 Stars 0%
1 Stars 0%
How can we improve this article?
Please submit the reason for your vote so that we can improve the article.
Previous Excessive peak broadening with partial loop fill
Next My peaks are (much) wider than to be expected
Table of Contents