The widespread use of pharmaceuticals has caused a growing concern on the presence of pharmaceuticals such as the antibiotic ciprofloxacin (CIPRO) in the aquatic environment, since they may exert adverse effects on non-target organisms, including fish. In order to study the uptake, distribution in different tissues (liver, muscle, brain and gill) and biofluids (plasma and bile), metabolism and elimination of CIPRO in gilt-head bream (Sparus aurata), controlled dosing experiments for 8 days at 200 μg/L concentration were carried out. CIPRO was only observed in bile at concentration up to 315 ± 4 ng/mL, probably due to its low octanol-water partition coefficient (log P = −2.4 at pH 7.4) and the zwitterionic behavior (pKa₁ = 5.76 and pKa₂ = 8.68). CIPRO by-products (BPs) were also identified in seawater environment, both in presence and absence of fish. The analysis done by means of liquid chromatography–high resolution mass spectrometry (hybrid quadrupole-Orbitrap) permitted the annotation of up to 35 BPs of CIPRO in seawater and bile, from which 30 structures were reported for first time. These results confirm that CIPRO is very susceptible to photolysis, and that it goes through various phase I and phase II metabolisms in the fish. All these results suggested that, for a complete characterization of CIPRO exposure, BPs should also be included in the biomonitoring campaigns since they might also be toxicologically relevant.

药物的广泛使用已引起人们对水生环境中诸如抗生素环丙沙星（CIPRO）之类药物的关注，因为它们可能对包括鱼类在内的非目标生物产生不利影响。为了研究不同组织（肝脏，肌肉，大脑和腮）和生物流体（血浆和胆汁）的吸收，分布，金头鲷（Sparus aurata）中CIPRO的代谢和消除，在8天内进行了剂量控制实验进行200μg/ L的浓度。仅在胆汁中以最高315±4 ng / mL的浓度观察到CIPRO，这可能是由于其辛醇-水分配系数低（pH 7.4时log P = -2.4）和两性离子行为（pKa ₁  = 5.76和pKa ₂ = 8.68）。在有鱼和无鱼的海水环境中，也可以识别出CIPRO副产物（BPs）。通过液相色谱-高分辨率质谱（混合四极杆-Orbitrap）进行的分析允许注释海水和胆汁中多达35个BP的CIPRO，其中首次报道了30个结构。这些结果证实CIPRO非常容易发生光解作用，并且在鱼类中经历了I和II期的各种新陈代谢。所有这些结果表明，对于CIPRO暴露的完整表征，BP也应包括在生物监测活动中，因为它们在毒理学上也可能是相关的。