Liquid chromatography–high resolution mass spectrometry with immunoaffinity clean-up for the determination of the oxidative stress biomarker 8-iso-prostaglandin F2alpha in wastewater

• 8-iso-PGF2α was for the first time quantitatively analysed in sewage by IAC–LC–HRMS.
• IAC allows efficient removal of matrix components and sufficient sensitivity.
• 8-iso-PGF2α was found to be stable in wastewater at least for 24 h.
• β-Glucuronidase treatment is essential to analyse total 8-iso-PGF2α in wastewater.

A reliable oxidative stress biomarker, 8-iso-prostaglandin F2α (8-iso-PGF2α), was for the first time quantitatively analysed in wastewater using an analytical method consisting of liquid chromatography–high resolution mass spectrometry coupled to immunoaffinity clean-up (IAC-LC-HRMS). Factors influencing the method's robustness were investigated, including analyte stability in sewage and enzymatic deconjugation with β-glucuronidase. The IAC-LC-HRMS method was linear over the range of 0.1–100 ng/mL with correlation coefficient (R2) of 0.999. The quantification limits were sufficiently low to detect 8-iso-PGF2α in sewage (method quantification limit of 0.3 ng/L) and precision, expressed as relative standard deviation was less than 7% and the accuracy expressed as relative recovery was in the 103–113% range. As a result, the application of the method to 24-h composite wastewater samples from Oslo showed 8-iso-PGF2α concentrations of 18.9–23.3 ng/L for 8 days in March 2015. This study demonstrates a standard method to analyse 8-iso-PGF2α in sewage that will contribute to the further investigation of the potential use of 8-iso-PGF2α as a sewage biomarker for assessing the status of community health.