Picogram-level quantification of some growth hormones in bovine urine using mixed-solvent bubble-in-drop single drop micro-extraction

Growth hormones are important biologically active compounds. However, they can cause deleterious effects if not used with care and their use in farmed animals is banned in the European Union. This study presents the development and application of a mixed-solvent “bubble-in-drop single drop micro-extraction” (BID–SDME) method for enrichment of stilbene hormones in bovine urine samples. The hormones are quantified using GC–MS showing good linearity with the coefficient of determination (R2) of 0.999 and 0.999 for hexestrol and diethylstilbestrol, respectively, in the concentration range 0.05–10ngmL–1. Excellent precision (RSD