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A novel analytical method employing solid-phase extraction (SPE) coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of 30 hormones in anti-ageing functional foods (capsules, powders and tablets). The analytes were extracted with acetic acid-acetonitrile (1-99 v/v), methanol and acetone, respectively. The extract was purified using a combined column, followed by analyte detection with electrospray ionisation in positive- or negative-ion modes. The results indicated that the 30 compounds had good linear correlations in the range of 1-1000 μg kg⁻¹, and the correlation coefficients were above 0.99. The limits of detection (LOD) and limits of quantification (LOQ) were 0.03-2 and 0.1-5 μg kg⁻¹, respectively. The average recovery of 30 compounds at the three spiked levels varied from 74.7% to 124.1%, and the relative standard deviation (RSD) was 2.4-15.0%. This method was applied to the analysis of hormones in 14 real samples of which seven hormones (such as estrone, dienestrol) were detected in four samples, but the remainder of the hormones were not detected. The developed method is sensitive, efficient, reliable and applicable to real samples.

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The electrochemical degradation of tetracycline antibiotics (TCs), such as tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC), was investigated by using SnO 2 -Sb 2 O 3 and PbO 2 modified Ti electrode (Ti/SnO 2 -Sb 2 O 3 /PbO 2 anode). The modified electrode was prepared with a SnO 2 -Sb 2 O 3 interlayer and a PbO 2 active layer on the surface of Ti sheet, and characterized by scanning electron microscope, X-ray diffraction and cyclic voltammetry. The effects of supporting electrolyte, current density and the initial concentration of TCs on electrochemical degradation were also examined. For the degradation of 50 mg•L −1 TC, OTC and CTC at 5 mA cm −2 , the energy consumption were 39.9, 40.0 and 37.7 kWhmol −1 , and the removal efficiencies could reach 79.5%, 82.0% and 90.3% for 2 h, respectively. The degradation processes followed the first-order kinetic model, and the rate constants of TC, OTC and CTC were 0.78, 0.84 and 0.97 h −1 , respectively. The possible degradation pathways were proposed through monitoring the degradation products of TCs. The results from bioluminescence inhibition assays suggested the residual biotoxicity after complete TCs degradation, and extra reaction was necessary to reduce biotoxicity. Overall, the electrochemical degradation using Ti/SnO 2 -Sb 2 O 3 /PbO 2 anode has a great potential to remove TCs from wastewater.