Off-line and real-time monitoring of acetaminophen photodegradation by an electrochemical sensor

Silvia Berto; Luca Carena; Enrico Chiavazza; Matteo Marletti; Andrea Fin; Agnese Giacomino; Mery Malandrino; Claudia Barolo; Enrico Prenesti; Davide Vione

doi:10.1016/j.chemosphere.2018.03.069

Off-line and real-time monitoring of acetaminophen photodegradation by an electrochemical sensor

Chemosphere. 2018 Aug:204:556-562. doi: 10.1016/j.chemosphere.2018.03.069. Epub 2018 Mar 13.

Authors

Affiliations

¹ Dept. of Chemistry, University of Torino, Via P. Giuria 7, 10125 Turin, Italy. Electronic address: silvia.berto@unito.it.
² Dept. of Chemistry, University of Torino, Via P. Giuria 7, 10125 Turin, Italy. Electronic address: luca.carena@unito.it.
³ Dept. of Chemistry, University of Torino, Via P. Giuria 7, 10125 Turin, Italy.
⁴ Dept. of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093-0358, United States.
⁵ Dept. of Drug Science and Technology, University of Torino, Via P. Giuria 9, 10125 Turin, Italy.
⁶ Dept. of Chemistry, University of Torino, Via P. Giuria 7, 10125 Turin, Italy; INSTM and NIS Centre, University of Torino, Via Quarello 15A, 10135 Turin, Italy.

PMID: 29602587
DOI: 10.1016/j.chemosphere.2018.03.069

Abstract

The photochemistry of N-acetyl-para-aminophenol (acetaminophen, APAP) is here investigated by using differential pulse voltammetry (DPV) analysis to monitor APAP photodegradation upon steady-state irradiation. The purpose of this work is to assess the applicability of DPV to monitor the photochemical behaviour of xenobiotics, along with the development of an electrochemical set-up for the real-time monitoring of APAP photodegradation. We here investigated the APAP photoreactivity towards the main photogenerated reactive transients species occurring in sunlit surface waters (hydroxyl radical HO, carbonate radical CO₃^-, excited triplet state of anthraquinone-2-sulfonate used as proxy of the chromophoric DOM, and singlet oxygen ¹O₂), and determined relevant kinetic parameters. A standard procedure based on UV detection coupled with liquid chromatography (HPLC-UV) was used under identical experimental conditions to compare and verify the DPV-based results. The latter were in agreement with HPLC data, with the exception of the triplet-sensitized processes. In the other cases, DPV could be used as an alternative to the well-tested but more costly and time-consuming HPLC-UV technique. We have also assessed the reaction rate constant between APAP and HO by real-time DPV, which allowed for the monitoring of APAP photodegradation inside the irradiation chamber. Unfortunately, real-time DPV measurements are likely to be affected by temperature variations of the irradiated samples. Overall, DPV appeared as a fast, cheap and reasonably reliable technique when used for the off-line monitoring of APAP photodegradation. When a suitable real-time procedure is developed, it could become a very straightforward method to study the photochemical behaviour of electroactive xenobiotics.

Keywords: Acetaminophen; Differential pulse voltammetry; Electrochemistry; Glassy carbon electrode; Paracetamol; Photochemistry.

MeSH terms

Acetaminophen / metabolism*
Biosensing Techniques / methods*
Electrochemical Techniques
Environmental Monitoring / methods*
Kinetics
Photochemistry*
Photolysis*

Substances

Acetaminophen