Micellar-extraction express determination of certain pharmaceutical arylamines

A method is proposed to lower the detection limit of p-aminobenzoic acid and some of its pharmaceutical derivatives in condensation reactions with p-dimethylaminobenzaldehyde. The approach is based on a combination of anionic catalysis (“micellar catalysis” effect) and preconcentration using nonionic surfactants (“micellar microextraction” effect). The conditions for obtaining micelle-saturated phases of Triton X-114 were optimized both in the absence and presence of sodium dodecyl sulfate (SDS) ions and micelles, reactants, and salting-out agents (NaCl, Na₂SO₄, Na₃C₆H₅O₇). As test media, micelle-saturated phases of Triton X-114 and SDS were proposed, which enable effective concentration of the Schiff base analytical forms of the analytes. These can then be determined at nanogram levels in aqueous solutions, blood plasma models, and pharmaceutical formulations at concentrations of approximately n × 10^–⁸ M using colorimetry methods enhanced by digital technologies.

arylamines, surfactants (SAA), micellar extraction (“cloud point” extraction, CPE-concentration), derivatization, spectrophotometry, express methods, mixed micelles of SAA