Prediction of measurement precision by chemometric invalidation of flow pulsation in refractive index detection of liquid chromatography

The standard deviation and relative standard deviation of measurements in t he refractive index detection of liquid chromatography are predicted based on the 1/f fluctuation model which is made up of white noise and the Markov process. First, repeated measurements and Monte Carlo simulation corrobora te the reliability of this prediction in the absence of flow pulsation. Pul sation, if any, can be distinguished in the frequency space from the 1/f no ise which is common to most analytical instruments. In this case, the uncer tainty prediction is also available without modifying the prediction theory , if a zero window is set at the time period of a fundamental tone of the p ulsation (virtual invalidation of pulsation). The zero window is used for d etermining the zero level relative to which the signal intensities are summ ed for a signal area (measurement). A maltose determination is taken as an example.