Multi-residue determination of 17 antibiotics in sea cucumbers (Holothuria tubulosa) by ultrahigh performance liquid chromatography-tandem mass spectrometry

Antibiotics are a class of pharmaceuticals routinely prescribed to prevent and treat infections caused by pathogenic bacteria in humans and animals. Their widespread consumption results in a gradual contamination of the aquatic environment, which is of particular concern due to the phenomenon of resistance to antibiotics. Quantitative analysis of antibiotics in marine ecosystems is critical to assess the potential risk of exposure of aquatic species and, consequently, of consumers of seafood. In this context, filter feeders, such as holothurians, are considered ideal bioindicators of pollution in marine waters. In this work, an ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the simultaneous determination of 17 multiclass antibiotic residues in Holothuria tubulosa specimens. The proposed methodology involved two steps of ultrasound-assisted extraction (UAE) with methanol, followed by a clean-up based on dispersive solid phase extraction (d-SPE) using C18 adsorbent. 3^2 factorial designs were used for the optimization of the most influential variables of the extraction procedure. Linearity of 84.1–99.4 %, precision in terms of RSD lower than 15 %, recoveries between 87.9 and 114.9 %, and detection limits between 0.3 and 3.0 ng g−1 were obtained. After validation, the method was used to analyze specimens of Holothuria tubulosa collected along the Mediterranean coast of Granada. The obtained results indicate the presence of antibiotics in the area, CIP being the most prevalent.