Based on the role of steady state concept in the model of analytical chemical measurement and deduction, the definition of 'practically steady state' (PSS) has been introduced. The definition does not require the process to be in steady state in a strictly mathematical sense. In order to fulfil the requirements of 'practically steady state' the random error and the systematic error must vary within a suitable limit, and the expected figure for the measured value must be within a specified range. The goal of the present investigation was to detect the steady state of measurement process with respect to the analytical information (peak area ratio) based on the measured values. The method proposed proved to be useful for the determination of the simultaneously present systematic error and random error. Control based on the measured values of the internal standard is useful, but additional information is necessary. These are several advantages to the method described: the results for the internal standard indicate possible sources of disturbances and allow the end of steady state measurement process to be predicted.
ASJC Scopus subject areas
- Clinical Biochemistry