Development and optimisation of an UHPLC-MS/MS method for analysis of veterinary drug residues – hormones in urine

Sammanfattning

Veterinary drugs, like hormones, are in some cases used on food-producing animals for growth promotion and the consumption of their residues causes health risks. In the EU, the use of hormones such as some anabolic androgenic steroids, corticosteroids, resorcylic acid lactones and stilbenes as growth promoters are prohibited and require proper monitoring in biological matrices, like urine. This study aimed to develop and optimise an existing UHPLC-MS/MS method for the detection of these prohibited substances in urine in accordance with the updated EU regulation 2021/808 and the associated EURL guidelines to enable subsequent method validation. Sample preparation included pH adjustment with phosphate buffer, hydrolysis with β-glucuronidase, automated solid-phase extraction (SPE), evaporation and dissolution. Thereafter, the samples were analysed by UHPLC-MS/MS. To reach the minimum method performance requirement (MMPR) of each analyte, as established by EURL, optimisation of mass spectrometry parameters and chromatographic conditions was performed. This resulted in successful detection of all 14 analytes in the negative ionisation mode method and 13 out of 17 in the positive ionisation mode method at their respective MMPR. Furthermore, the method showed stability and acquired high linearity (R2 > 0.99) which indicates the possibility of eventual method validation. However, to reach the point of validation, improvements in the detection of the 4 analytes at their MMPR and lower are required.