Sample Preparation Approaches for Determination of Quinolones in Aqueous Matrixes: Systematic Review

Quinolones and fluoroquinolones are among the most used antibiotics worldwide. Antibiotic resistance genes can be acquired by human pathogens from ambient microorganisms, which can lead to a treatment failure for bacterial infections. Furthermore, determining the levels of quinolones and fluoroquinolones in aqueous matrixes is crucial for safeguarding both human health and the environment. Using sample preparation techniques is essential since these compounds are commonly present in aqueous matrixes at trace levels. Therefore, we aimed to investigate the main analytical methods for the determination of quinolones in aqueous samples based on a systematic literature review. We only considered studies that presented more robust analytical techniques that allowed for more accurate and precise measurement of quinolones/fluoroquinolones in aqueous matrixes. In total, 18 articles met the inclusion criteria and were used in our analysis. A total of 21 quinolone antibacterial agents were investigated in water samples from 13 countries, showing a potential risk around the world. Ciprofloxacin (72.2%), enrofloxacin (61.1%), norfloxacin (50%), marbofloxacin, and levofloxacin (33.3%) were the most frequently evaluated compounds. High-Performance Liquid Chromatography stands out as the predominant instrumental technique for the separation and identification of these compounds. Additionally, among the selected studies in this review, 44% employed liquid-liquid extraction techniques and its miniaturized versions, while 56% opted for solid-phase extraction and its miniaturized variations. Finally, it is important to note that the final method efficiency relies on the entire process, from selecting the instrumental technique with appropriate detection limits, going through the entire sample preparation, to achieving a good recovery through adjustments in the extraction parameters to archive the determination of trace levels.