João Rosa

Multi-residue and multi-class determination of antibiotics in gilthead sea bream (Sparus aurata) by ultra high-performance liquid chromatography-tandem mass spectrometry

This paper describes a method for the determination of 41 antibiotics from seven different classes in gilthead sea bream (Sparus aurata) by ultra-high-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS). Sulfonamides, trimethoprim, tetracyclines, macrolides, quinolones, penicillins and chloramphenicol were simultaneously determined. Fourteen procedures for sample treatment were tested and an extraction with acetonitrile and ethylenediaminetetra acetic acid was found to be the best option. The methodology was validated in accordance with Decision 2002/657/EC. Precision in terms of relative standard deviation (RSD) was under 17% for all compounds, and the recoveries ranged from 92% to 111%. CCα and CCβ were determined according to the maximum residue limit or the minimum required performance limit, when necessary. The validation provided evidence that the method was suitable for application in routine analysis for the detection and confirmation of antibiotics in muscle of gilthead sea bream, an important and intensively produced fish in aquaculture. Graphical Abstract

A multiresidue approach for the simultaneous quantification of antibiotics in macroalgae by ultra-high performance liquid chromatography-tandem mass spectrometry.

Together with fish, algae reared in aquaculture systems have gained importance in the last years, for many purposes. Besides their use as biofilters of effluents, macroalgaes rich nutritional profiles have increased their inclusion in human diets but also in animal feeds as sources of fatty acids, especially important for the fish industry. Nonetheless, algae are continuously exposed to environmental contaminants including antibiotics and possess the ability for bioaccumulation of such compounds. Therefore, the present paper describes the development and validation of an ultra-high performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification of antibiotics in the green macroalgae Ulva lactuca. This multi-residue method enables the determination of 38 compounds distributed between seven classes and was fully validated according to EU Decision 2002/657/EC.

Screening of human and veterinary pharmaceuticals in estuarine waters: A baseline assessment for the Tejo estuary

We investigated the presence of 66 human and veterinary pharmaceuticals from seven therapeutic groups in surface waters of the Tejo estuary. Collection sites covered the entire estuary and included areas near main river inflows and wastewater treatment outfalls, traversing urban, agriculture, aquaculture, and nature reserve areas. Detection of pharmaceuticals was performed via UHPLC-TOF-MS. Pharmaceuticals were found in all sites (32 different compounds in total). Antibiotics, β-blockers, antihypertensives and anti-inflammatories were the most frequently detected (>90%), with variation in concentrations reflecting the multifaceted nature of estuarine surroundings (accumulated site contamination between 15 and 351 ng L-1). Higher concentrations of antidepressant Sertraline (304 ng L-1), non-steroidal anti-inflammatory Diclofenac (51.8 ng L-1), lipid regulator Gemfibrozil (77.0 ng L-1), antihypertensive Ibersartan (161.9 ng L-1) or antibiotic Doxycycline (128.0 ng L-1), among others, though localized may potentially impact key estuarine functions or services. Ultimately, results provide a baseline for regulatory information and future biota evaluations.

Prospection, Collection, and Preservation of Marine Samples

Abstract Organisms thriving in the marine environment, living under unique conditions of temperature, pressure, and even chemical surroundings are responsible for the presence of countless bioactive compounds with commercial potential. Bioprospecting can be defined as the collection of such biological materials, as well as the analysis of its properties and contents, with the purpose of developing a commercial product. Thus, the present chapter will focus on the different sampling strategies that have to be taken into account to ensure the appropriate collection of micro- and macroorganisms from natural marine environments. Also, bioprospecting in extreme environments will be addressed due to their peculiar characteristics, together with the preservation of samples.