Pressurised liquid extraction and ultra-high performance liquid chromatography-tandem mass spectrometry to determine endogenous and synthetic glucocorticoids in sewage sludge

Glucocorticoids are a type of steroid hormones classified as endocrine disrupting chemicals (EDCs) and they are widely used by human and animal medicine. In this paper, we describe the development and validation of an analytical method for the determination of 9 selected glucocorticoids (betamethasone, cortisol (hydrocortisone), cortisone, dexamethasone, flumethasone, methylprednisolone, prednisolone, prednisone and triamcinolone acetonide) in sewage sludge by pressurised liquid extraction (PLE) and ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS). PLE with on-cell clean-up followed by solid-phase extraction (SPE) clean-up (Oasis HLB) has been applied to extract the analytes and clean up the matrix. Recoveries of the method were from 8% for prednisone and cortisone to 73% for triamcinolone acetonide. The developed method achieves limits of detection (LODs) between 1 and 5 μg/Kg dry weight (d.w.) in sludge and the repeatability expressed as relative standard deviation (%RSD, 50 μg/Kg (d.w.), n=3) is less than 8%. The PLE/SPE/UHPLC-MS/MS method was successfully applied to determine these pollutants in sludge samples from two sewage treatment plants located in the Tarragona area. Cortisone was found at levels below LOQ, cortisol between 5.2 and 6.1 μg/Kg (d.w.) and prednisolone between

► PLE/SPE/UHPLC-MS/MS method to determine 9 glucocorticoids in sewage sludge.
► This method is the first that uses PLE to extract glucocorticoids from sludge samples.
► Limits of detection and quantification at low μg/Kg (d.w.) levels were obtained.
► Endogenous and synthetic glucocorticoids were found in analysed sludge samples.