Development and application of a calibration regression routine in conjunction with linear and non-linear chromatographic detector responses.
Linear regression is widely used in the calibration of chromatographic assays even in conjunction with some chromatographic detectors which show significant non-linearity in their response characteristics. A calibration routine, based upon the curve y = axlnx+bx+c is presented which describes the non-linear behaviour of some chromatographic systems, including electron capture, nitrogen-phosphorus and UV photometric detectors, and gives comparable results to weighted linear regression with assays showing linear concentration versus response relationships. The ratio of the coefficients a and b in the equation allows quantification of the deviation from linearity and provides a more sensitive indicator of linearity than the correlation coefficient often quoted with linear regression.
Burrows
J L
JL
Bioanalytical Department, Hoechst Pharmaceutical Research Laboratories, Walton, Milton Keynes, Bucks, UK.
Watson
K V
KV
D001774:Blood Chemical Analysis; D002138:Calibration; D002845:Chromatography / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry; D006801:Humans; D009010:Monte Carlo Method; D012044:Regression Analysis; D013056:Spectrophotometry, Ultraviolet