Predicting liquid chromatography-electrospray ionization/mass spectrometry signal from the structure of model compounds and experimental factors; case study of aripiprazole and its impurities.

A priori estimation of analyte response is crucial for the efficient development of liquid chromatography-electrospray ionization/mass spectrometry (LC-ESI/MS) methods, but remains a demanding task given the lack of knowledge about the factors affecting the experimental outcome. In this research, we address the challenge of discovering the interactive relationship between signal response and structural properties, method parameters and solvent-related descriptors throughout an approach featuring quantitative structure-property relationship (QSPR) and design of experiments (DoE). To systematically investigate the experimental domain within which QSPR prediction should be undertaken, we varied LC and instrumental factors according to the Box-Behnken DoE scheme.

Direct determination of lead in blood by differential pulse stripping voltammetry.

A simple and rapid method for determination of lead in blood by differential pulse stripping voltammetry (DPS) without preliminary mineralization of the sample, is described. Lead determination was performed in native samples of blood in the electrolyte of Britton-Robinson buffer (pH 5-5.5).