title: Ruggedness testing of chromatographic methods: selection of factors and levels.
abstract: The first step in a ruggedness test is the selection of factors to be examined and their levels. In this paper, both topics are discussed, thereby completing a strategy described earlier. It is demonstrated, by means of some examples, that depending on the formulation (definition) of a factor, information that is physically more or less meaningful is extracted from the experimental design results. Among others, the inclusion of the compounds of a buffer and of the components of a mixture in a screening design were examined. A general guideline to select the levels of the factors in a ruggedness test was proposed. Some special cases, i.e. asymmetric intervals around the nominal level, were also discussed.
authors.affiliation: ChemoAC, Pharmaceutical Institute, Vrije Universiteit Brussel, Brussels, Belgium.
authors.forename: Y
authors.initials: Y
authors.lastname: Vander Heyden
authors.forename: F
authors.initials: F
authors.lastname: Questier
authors.forename: L
authors.initials: L
authors.lastname: Massart
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002845:Chromatography / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity