Figures of Merit

Abstract

Figures of merit are numerical parameters, usually employed for comparing analytical methods in terms of predictive ability and detection capabilities. The estimation of analytical figures of merit for calibrations based on first- and higher-order data has become an active research field in recent years. The starting approach was to extend the well-known univariate calibration concepts todata of increasing complexity. For example, the sensitivity, which is a key figure of merit for qualifying analytical methods, is correctly interpreted in the framework of classical univariate calibration as the change in response (the analytical signal) for a given change in stimulus (the analyte concentration). This concept was extended to multivariate and multi-way calibration using the net analyte signal (NAS) as an analogue of the raw instrumental signal in univariate calibration.5,6 The notion of net analyte signal is attractive, because it measures, in principle, the portion of the overall signal which can be directly employed to quantitate a givenanalyte in the presence of interferents. However, this approach proved to be unsuccessful to estimate the sensitivity, particularly in multi-way calibration.