Carbon nanotubes in high internal phase emulsion polymer composite for packed-cartridge micro-solid-phase extraction of fluoroquinolones in urine

• Published in: Advances in sample preparation 2024-02, Vol.9, p.100103, Article 100103
• Main Authors: Merlo, Francesca, Colucci, Francesca, De Soricellis, Giulia, Rinaldi, Francesca, Calleri, Enrica, Profumo, Antonella, Speltini, Andrea
• Format: Article
• Language: English
• Subjects: Biological samples; Carbon nanotubes; Fluoroquinolones; PolyHIPE; Sample preparation; SPE
• ISSN: 2772-5820; 2772-5820
• DOI: 10.1016/j.sampre.2024.100103

•New insights in application of polyHIPE materials to analytical sample treatment.•Application of CNT/polyHIPE composite as sorbent phase in biological matrix.•µSPE of trace fluoroquinolones in raw human urine prior to HPLC-MS/MS.•Proof-of-concept analysis of real-life urine samples. Aim of this study stands in the evaluation of a carbon nanotubes-based polymerized high internal phase emulsion composite (CNT/polyHIPE) as sorptive phase in biological sample preparation. A micro-solid-phase extraction procedure (µSPE) was developed for trace fluoroquinolone (FQ) antimicrobials, namely Ciprofloxacin, Levofloxacin, Lomefloxacin, Moxifloxacin, Norfloxacin and Sparfloxacin, in human urine samples. PolyHIPEs modified by incorporation of different concentrations of nanotubes (0.2–0.8 wt %) were one-pot synthesized and applied in the packed-cartridge setting. The sorption affinity for the drugs was investigated in tap water and buffered aqueous solutions, demonstrating the key role of the nanotubes embedded in the polymer. The 0.5 wt % CNT composite was selected to develop a straightforward µSPE procedure directly in raw urine (1 mL sample), followed by HPLC-MS/MS. Targets were retained on the sorbent at near neutral pH and, after an aqueous washing (0.1 % v/v formic acid), eluted in a single-step with 4 % v/v ammonia aqueous solution (15 % v/v acetonitrile), thus combining extraction and clean-up. The method allowed accurate quantification of FQs, as evidenced by the recoveries (74–116 %, n = 3) obtained on blank pooled urine samples spiked with 40, 75, 150 µg L−1, accompanied by good inter-day precision (RSD