Peroxidation of diclofenac under microdispersed electrospray conditions

This paper presents a new approach to studying diclofenac (DCL) peroxidation products and their reactivity, based on a combination of LDI target surface functionalization and modeling of the electro-Fenton reaction under microdispersed electrospray (MED) conditions. To ensure active interaction of diclofenac molecules with hydroxyl groups, peroxidation was carried in the presence of Cu+ ions, which promoted the formation of hydroxyl radicals. The peroxidation products and their adducts with glutathione were determined using SALDI/MALDI mass spectrometry. This study demonstrated that the use of a microdisperse electrospray system in combination with peroxidation enables the efficient isolation of diclofenac metabolites from the first and second stages. SALDI and MALDI analysis of diclofenac peroxidation products revealed new oxidative transformation products and glutathione adducts. The use of a microdisperse electrospray system significantly accelerated the modeling of oxidation processes compared to traditional methods, allowing the deposition and recording of the resulting products in the presence of titanium dioxide nanoparticles on the surface of an LDI target in parallel with oxidation reactions. In this case, the deposited particles serve as ion emitters for SALDI-MS analysis. The obtained results open new horizons for faster and more accurate analysis of drug biotransformation products. The development and implementation of this approach can significantly accelerate the process of assessing the toxicity of pharmaceuticals.