Rapid determination of hippuric acid as an exposure biomarker of toluene using a colorimetric assay and comparison with high-performance liquid chromatography.

Occupational exposure to toluene is associated with health risks that require reliable monitoring methods. Hippuric acid (HA), a urinary metabolite of toluene, serves as a valuable biomarker for such exposure. Colorimetric methods for the quantitative determination of HA have gained prominence due to their simplicity, cost-effectiveness, and suitability for field application.

Photodegradation study of nystatin by UV-Vis spectrophotometry and chemometrics modeling.

Nystatin, one of the tetraene antifungal antibiotics, is very sensitive to light. Thus, when nystatin is exposed to natural daylight, it is photodegraded to products of lower biological activity. In this work, the photodegradation kinetics of nystatin was monitored by a UV-Vis spectrophotometry method.

Spectrophotometric study of complex formation equilibria in the presence of interference using hard-soft net analyte signal method: application to drug-metal complexation.

In this article, the ability of a new and efficient hard-soft method, previously proposed by our research group, is reported for modeling of the complex formation equilibria in the presence of interferences. This method is based on the net analyte signal (NAS) concept, which is a part of total signal that is directly related to the concentration of the component of interest. It monitors the concentration changes of any chemical species involved in the evolutionary process without requiring any pure spectra or having previous knowledge about the presence of the interferences.