This study presents an example of method validation, applied to an IIR-RP-H
PLC method, developed for the separation of nine PPPs (Priority Pollutant P
henols). The parameters of both primary validation (accuracy, precision, re
sponse linearity, detection. and quantitation limits,) and of secondary val
idation (method ruggedness) are evaluated. The glossary used in literature
for ruggedness and rabustness is discussed. The robustness test is carried
out with respect to five chromatographic conditions, both depending on anal
yst accuracy (concentration of the ion-interaction reagent, concentration o
f the organic modifier, and pH of the mobile phase) and on instrumentation
(column temperature and few-rate).
The effect of the experimental factors is studied by a fractional factorial
design and mathematical models are built, that correlate the chromatograph
ic retention to the experimental factors and to their interactions. The cro
ss-validated models can usefully be employed to evaluate for each studied v
ariable the region of acceptable ruggedness for any given confidence level.