Why does sensitivity of ninhydrin response sometimes decrease with time?

Potential causes of decreasing ninhydrin sensitivity:

  1. Low grade nitrogen or inert gas supply (must be 99.999%) used in preparation or on instrument.
  2. Incomplete dissolution of reagent before use.
  3. Nitrogen supply interrupted:
    1. Cylinder valve stuck
    2. PTFE purge tube trapped or disconnected
    3. Reservoir bottle seal leakage
    4. Reservoir still contaminated with detergent after washing (also gives yellow or pink colours with Virkon, decon).  Use only water for rinsing reservoir.

 

If this does not answer your question or solve your problem, then please contact us at support@biochrom.co.uk detailing your question or the problem you are experiencing.  Please list if relevant the instrument, software and version numbers you are running, and enclose any relevant data files, etc.