Abstract
The H-point standard addition method (HPSAM) is a modification of the standard addition method that transforms the incorrigible error resulting from the presence of a direct interferent in the determination of an analyte into a constant systematic error. This error can then be evaluated and eliminated. The method was established for resolving strongly overlapping spectra of two analytes and permits both proportional and constant errors produced by the matrix of the sample to be corrected directly. The technique is based on the principle of dual-wavelength spectrophotometry and the standard addition method. The application of the method requires only two wavelengths, and the analytical signal caused by one of the species should be constant and that of the other should differ as much as possible. This overview discusses both the theoretical and practical aspects of HPSAM applications.