HPLC-HRMS determination of anticancer drugs and their degradants identified by heterogeneous photocatalysis as potential river toxicants.

Abstract

Anticancer drugs are considered pseudo-persistent pollutants for the water environmental compartments due to their continuous emission into water bodies. Many sources contribute to the bioaccumulation of the drugs, and the investigation of their residues and transformation products (TPs) fate is mandatory, in particular for compounds displaying a high degree of toxicity. Here, we present a High-Performance Liquid Chromatography - High-Resolution Mass Spectrometry (HPLC-HRMS) method developed to identify and characterize the TPs of cyclophosphamide (CYC), 5-fluorouracil (5FU) and oxaliplatin (OXA), subjected to heterogenous photocatalysis mediated by titanium dioxide. The irradiation experiments were performed at different times, and the HPLC separation was achieved using a reverse-phase column. A high-resolution Orbitrap mass analyzer was used in the positive and negative ionization modes with a resolution of 30k. Tandem mass spectrometry experiments were acquired in the CID activation mode. With the developed method, we recognized and tentatively assigned the structures of six TPs for CYC, four TPs for 5FU and one TPs for OXA. The developed analytical method was then applied to real environmental water samples coming from nine sampling sites of Po River (Italy). We found the presence of CYC in four site points at level of ppb. The developed HPLC-HRMS method was a satisfactory tool to identify anticancer drugs and their TPs and to quantify them in real water environmental samples.