Deductive Prediction of Measurement Precision from Signal and Noise in Photomultiplier and Photodiode Detector of Liquid Chromatography

Abstract

Tokyo 158, JapanRecently, a probability theory to predict the precision or relative standard deviation (RSD) of measurements in analytical instruments has been proposed. The aim of this paper is to examine the precision of data obtained by a high-performance liquid chromatograph (HPLC) equipped with photodiode detector and photomultiplier on the basis of the abovementioned theory. The baseline drift, which is often formulated as 1/f noise, is approximated by the mixed random process of white noise and Markov process. Of six parameters necessary for the uncertainty prediction, three parameters are determined from the power spectral density of the baseline drift: the standard deviations (SD), w, of the white noise and the SD, m, and retention parameter, p, of the Markov process. The others are signal domain, kf, signal area, A, over domain, k f, and independent error, I (mainly from the injection error). No arbitrary constants are involved. The prediction is shown to be superb for peaks with various areas, heights and widths over a wide concentration range in the HPLC analysis for some aromatic compounds. The applicability of the uncertainty prediction in analytical chemistry is discussed.

Deductive Prediction of Precision in Measurement, Calibration, and Standard Addition Method in Atomic Absorption Spectrometry for Cadmium

“…Although the white noise is exactly the same as the shot noise in mathematics, the 1/ f noise (flicker noise) is approximated by a mixture of the Markov process (1/ f 2 noise) and white noise (1/ f 0 noise) . However, as far as the uncertainty prediction is concerned, the idiosyncrasy of the FUMI theory is satisfactory. ,,,, …”

Development of a Methodology for Estimating the Ergosterol in Meat Product-Borne Toxigenic Moulds to Evaluate Antifungal Agents

“…MP3 also showed the best results for the peak width and asymmetry values ( Table 2 ). A symmetrical, sharp peak with a narrow width (asymmetry value close to 1) has higher precision and is better separated than a more curved peak [ 35 , 36 ]. Such differences between mobile phases are shown in the chromatograms included in Figure 2 .…”

Uncertainty Estimates of Purity Measurements Based on Current Information: Toward a “Live Validation” of Purity Methods

“…The FUMI theory requires parameterization of the Fourier transformed noise (power density spectrum) to compute the value of the noise parameters for the chromatographic measurements (22,25). However, the power density spectrum showed distinct regular features that made the spectrum difficult to parameterize per the Hayashi and Matsuda method.…”

“…Stimulated by the work of Hayashi and Matsuda on FUMI theory ( 22 , 25 ), which relates the stochastic properties of background noise to method precision, we turned our attention to chromatographic noise ( 39 , 40 ) with the intention of finding an explanation of these intriguing observations regarding precision, specifically, a significant variability in the determination of precision for individual analytes, and a close relationship between repeatability and intermediate precision. The FUMI theory requires parameterization of the Fourier transformed noise (power density spectrum) to compute the value of the noise parameters for the chromatographic measurements ( 22 , 25 ). However, the power density spectrum showed distinct regular features that made the spectrum difficult to parameterize per the Hayashi and Matsuda method.…”