Determination of amantadine and rimantadine in chicken muscle by QuEChERS pretreatment method and UHPLC coupled with LTQ Orbitrap mass spectrometry

A novel sample pretreatment method was developed for the quantitative determination of amantadine and rimantadine in chicken muscle tissues by ultra high performance liquid chromatography coupled with high resolution LTQ Orbitrap mass spectrometry (UHPLC-LTQ Orbitrap MS). The samples were pretreated by modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method, using acetonitrile (1% acetic acid, v/v) as extraction solution and C18 sorbent for clean-up. The separation was carried out on a Waters ACQUITY UPLC HSS T3 column (150 mm × 2.1 mm, 1.8 μm particle), using a mobile phase of acetonitrile and 0.1% aqueous formic acid solution. LTQ Orbitrap MS with resolving power of 60 000 was applied for analysis of the samples. Amantadine and rimantadine were identified from their accurate mass (within 5 ppm) and retention times from the acquired full-scan chromatogram and quantified by their peak areas. The linear range for the determination of the analytes was 1–100 μg/kg. Limits of detection (LODs) for amantadine and rimantadine were 1.02 μg/kg and 0.67 μg/kg, respectively. The intra- and inter-day accuracy ranged from 87.5% to 102.4%, and 82.5% to 105.8% for amantadine, and 95.3% to 97.4%, and 89.4% to 93.2% for rimantadine, respectively. The precision of intra- and inter-day was between 3.9–6.3% and 5.95–13.9% for amantadine, 6.0–7.45% and 7.8–12.4% for rimantadine, respectively. Finally, the method was applied for the determination of these antiviral agents in routine samples, and amantadine residue was detected in some cases.