Linearity of Chromatographic Systems in Drug Analysis Part Iii: Examples of Nonlinear Drug Assays

Chromatography-based drug assays are generally considered to be linear, provided that the back calculated concentrations of 75% of the calibrators are within ±15% of their target values. Data meeting this criterion are not usually subject to further examination in order to evaluate the extent of any...

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Bibliographic Details
Published inBioanalysis Vol. 7; no. 14; pp. 1763 - 1774
Main Authors Burrows, John, Watson, Kenneth
Format Journal Article
LanguageEnglish
Published England 01.01.2015
Subjects
Chromatography - methods
Nonlinear Dynamics
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Summary:Chromatography-based drug assays are generally considered to be linear, provided that the back calculated concentrations of 75% of the calibrators are within ±15% of their target values. Data meeting this criterion are not usually subject to further examination in order to evaluate the extent of any nonlinearity and whether use of a nonlinear calibration function would improve the accuracy. Examples of nonlinear behavior are presented for several chromatographic systems and most are best described by the nonlinear equation y = a + bx + cxln(x). A more critical evaluation of linearity, as presented herein, can lead to the identification of nonlinear behavior and an improvement in accuracy by use of a nonlinear calibration regression.
ISSN:1757-6180
1757-6199
DOI:10.4155/bio.15.105