Calibration by the standard addition and indicative dilution method in flame atomic absorption spectrometry

Abstract

A simple novel calibration approach called ‘the standard addition and indicative dilution method’ (SAIDM) is presented. It consists in addition of a standard solution to a sample and in successive dilution of this solution until the signal measured is equal to the signal produced by the undiluted sample. Due to the presence of the analyte in the sample environment, SAIDM can be effectively used when interference effects occur. It has been theoretically and experimentally proved that the method proposed is capable of overcoming strong interferences in flame atomic absorption spectrometry even in such cases where the standard addition method (SAM)—conventionally used for this purpose—fails. In addition, due to the possibility of avoiding the extrapolation process, it offers better precision than SAM. However, it has also been revealed that SAIDM cannot be considered as a versatile calibration approach because it leads to worse analytical results in terms of accuracy than SAM when the interference effect is of a multiplicative character.