H-point standard additions method. Part 1. Fundamentals and application to analytical spectroscopy

Abstract

A modification of the standard additions method called the “H-point standard additions method” is proposed in order to obtain an unbiased analyte concentration when both analyte and interferents are present in a sample. It also permits the determination of an interferent known to be present. The method uses the analytical signal data at two selected wavelengths, giving two straight lines that have a common point with coordinates H (–C_H, A_H), where –C_H is the unknown analyte concentration and A_H the analytical signal due to an interferent. Examples of the application of the proposed method are given.