Measurement and Results - Acceptable linearity slope variance
We have performed a linearity study from low to high concentrations for different metals. The slopes were recorded for 0:10, 0:20, 0:50, 0:100, and 0:150 ppb. We were wondering if you knew of literature recommending the maximum allowed % difference between the slopes before data calculations became compromised or biased.
| Responses | |
|---|---|
|
admin
Total posts: 529
|
Each analyst has to ask, "What is the purpose of the method and what variance is allowable?" As we focus upon the purpose of the method, we begin to define what deviation can be allowed (i.e., we begin to define boundaries based upon the purpose of the method). The method validated should always consider the concept, 'fit the purpose', and these criteria are then defined as part of the method validation process. I know of a commercially available program (STATISTICA) that might help. This program computes various statistics related to gage linearity and accuracy. The output includes the following and may prove useful for your purposes:
|