Analytical Method Validation With Definitions

Analytical Method Validation With Definitions

1. Accuracy

The accuracy of an analytical method is the closeness of test results obtained by that method to the true value.  The accuracy of an analytical method should be established across its range.
2. Precision

The precision of an analytical method is the degree of agreement among individual test results when the method is applied repeatedly to multiple samplings of a homogeneous sample.
3. Specificity

The specificity of an analytical method is the ability to assess unequivocally the analyte in the presence of components that may be expected to be present, such as impurities, degradation products, and matrix components.
4. Detection Limit

The detection limit of an analytical method is the lowest amount of analyte in a sample that can be detected, but not necessarily quantitated, under the stated experimental conditions.

5. Quantitation Limit

The quantitation limit of an analytical method is the lowest amount of analyte in a sample that can be determined with acceptable precision and accuracy under the stated experimental conditions.

6. Ruggedness (Intermediate precision)

The ruggedness of an analytical method is the degree of reproducibility of test results obtained by the analysis of the same samples under a variety of conditions, such as different laboratories, different analysts, different instruments, different lots of reagents, different elapsed assay times, different assay temperatures, different days, etc.  Ruggedness is normally expressed as the lack of influence on the test results of operational and environmental variables of the analytical method.  Ruggedness is a measure of reproducibility of test results under the variation in conditions normally expected from laboratory to laboratory & from analyst to analyst.
7. Linearity

The linearity of an analytical method is its ability to elicit test results that are directly, or by a well-defined mathematical transformation, proportional to the concentration of analyte in samples within a given range.
8. Range

The range of an analytical method is the interval between the upper & lower levels of analyte (including these levels) that have been demonstrated to be determined with a suitable level of precision, accuracy, & linearity using the method as written.
9. Robustness
It is the reliability of an analysis with respect to deliberate variations in method parameters.
Examples of typical variations are :
Stability of analytical solutions.
extraction time.
pH of mobile phase.
different column makes.
Temperature.
Flow rate.