Rapid Colorimetric Determination of Biologically Active Organic Analytes

Four types of reactions (azo coupling, protolytic and oxidative condensation, ion association), accompanied by the formation of hydrophobic colored analytical forms of corresponding organic analytes, are proposed on an example of biologically active substances (aromatic amines, α-amino acids, antibiotics of aminoglycoside and β-lactam series, anionic surfactants). It is shown that, in these systems, the hydrophobicity of both the initial reactants, e.g., tetrafluoroborates of diazonium salts, and analytical forms (azo compounds, Schiff bases, Ruemann’s purpura, ion associates with surfactants) can be increased. Possibilities of various methods for the derivatization of organic analytes with the formation of colored analytical forms with increased hydrophobicity for the best fixation on solid matrices and the development of test systems on their basis, which can be used to control the quality of various samples with rather good performance characteristics, are considered.