Case study of Incident observed during HPLC analysis

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Case study of Incident observed during HPLC analysis on Waters auto sampler:

 

Recently during HPLC analysis on Waters make HPLC, a very unique incident happened.

During Related substance analysis, after 3 standard injection, in fourth injection missing vial was observed though injection was taken from same single vial.

Root cause analysis:
Further on investigation it was identified that at the time of vial labelling, analyst used small sticker. So at the time of vial picking by robot in autosampler, small piece of sticker on inside wall of vial carousol. Due to this robot tried to pick the vial but due to resistance from vial, robot was not able to pick the vial.

This resulted in above incident and missing vial message was obseeved.

On prima facie it was difficult to find the root cause but due to so small sticker, such sticker can cause the incident.

Remedy: 
Never apply sticker labels on vials and always use marker pen to assign the identification on vial.

Hope you may get some help after reading above incident to attend the trobleshooting
 




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