Method Verification Part II TDLM Workshop · TDLM Symposia on Importing a Method – Degrees of...
Transcript of Method Verification Part II TDLM Workshop · TDLM Symposia on Importing a Method – Degrees of...
Method Verification Part IITDLM Workshop
John Szpylka, Ph.D.Technical Manager
Medallion Laboratories
AOAC Int’l Annual MeetingDallas, TX
September 2008
Last Year Started It All . . .
TDLM Symposia on Importing a Method– Degrees of importing– Using available data– Depth of verification– Ongoing competency tracking
Kicked off ALACC Guidance Document– Free on AOAC Website
Why Import A Method?
All the method development work has been done.Method performance understood.
Why Import A Method?
“Official” methods used to settle disputes.Inter-laboratory proficiency testing may already be in place.
Once Imported . . .
Must show you can do the method correctly at your site!
Degrees of Importing Methods
Performing the method exactly as written“Slightly” modifying the methodModifying the Method
Matrix Application
%CARBOHYDRATES0%100%
J. AOAC, 83 (2), 413 (2000)“The Referee”, AOAC Int’l, July 1993
Ready To Use Methods
Slightly modified– It’s always wise to have supporting data
You Never Know!
– Prove or state that modifications have no or understood effect
– Must have supporting documentation– May use validation data
Ready To Use Methods
Modified– Supporting data is a must!– Examples
different column,different detector,change of sample weights, dilutions or other sample preparation steps,solvent switch.
Verification is a “Mini-Validation”
Pull method performance during original validations (SLV and MLV)– See if you can repeat performance
To evaluate matrix effects
Analyst CompetencyTraining– Establish a written list of steps to document the training
procedure.
Our labs require– 7 replicates of a known NIST or Internal Reference Material, or– 7 side-by-side with expert.– Optional spike/recovery and/or matrix challenge.
Compare average, st. dev., and statistical analyses (ANOVA or t-Test).
Ongoing Demonstration ofMethod Performance
Participate in Proficiency testing ProgramDuplicate analysesControl Chart
Ongoing Demonstration ofMethod Control
Date/Time
Mea
sure
men
t
Average
+ 1 std dev
+ 2 std dev
+ 3 std dev
- 1 std dev
- 2 std dev
- 3 std dev
Takeaways
Importing a method is truly an adoption– Be prepared to adopt– Welcome it to your home– Take care of it– Keep it healthy– Be prepared for it to grow
This Year Goes tothe Next Level
Take what I learned last yearTake the ALACC Guidance documentShow Me How!
Thank You!Let’s Get Started!!