Phase I: Laboratory Investigation
• Upon observation of an OOS/OOT result, the Analyst should immediately inform the
Supervisor. Together, they should determine if an assignable cause for the result
exists by reviewing the following:
Raw data Review chromatograms and print outs
Compare results to historical data or trends
Sample
considerations
Was the correct sample tested?
Is there evidence of contamination or improper sample appearance, storage, handling,
labelling or damage.
Inspect the sample in the original container and all sample preparations to determine if
samples have been compromised or may not have been fully extracted
Equipment Was the correct equipment used and were the settings correct?
Are there any indications of equipment malfunction? Is the calibration/maintenance current?
Were system suitability parameters met?
Test execution &
analyst training
Was the correct method used? Was the raw data properly documented? Was the analyst
trained on the technique?
Standard & sample
preparations
Check the standards, solvents and reagents to determine if they are correct and have been
preconditioned properly
Were correct standards/chemicals used? Was the sample powder homogenous? Were all
solutions prepared correctly?
Review other test
results within the
run
Are the results acceptable?
Is there a clear bias to the run?