Simultaneous trace-level monitoring of seven opioid analgesic drugs in biological samples by pipette-tip micro solid phase extraction based on PVA-PAA/CNT-CNC composite nanofibers followed by HPLC-UV analysis

Electrospun poly(vinyl alcohol)-(PVA)-poly(acrylic acid) (PAA)/carbon nanotubes(CNTs)-cellulose nanocrystal (CNC) (PVAPAA/CNT-CNC) composite nanofibers were prepared and characterized using Fourier transform-infrared spectroscopy and field emission scanning electron microscopy. The resultant composite was used as an effective and novel sorbent for pipette-tip microsolid phase extraction (PT-RSPE) of seven opioid analgesics (OAs) in biological samples followed by HPLC-UV analysis. Addition of CNT-CNC with the high specific surface area and plenty of OH-functional groups endows the nanofibers with considerable extraction efficiency. Under the optimum conditions, the linearity was obtained in the range 1.5 to 700.0 ng mL(-1) for morphine, codeine, oxycodone, and tramadol, and 0.5 to 1000.0 ng mL(-1) for nalbuphine, thebaine, and noscapine with coefficient of determination (r(2)) >= 0.9990. Detection limits (LODs) based on S/N = 3 were in the range of 0.15-0.50 ng mL(-1) . The relative standard deviations (RSDs) of 4.1-5.4% (intra-day, n = 5) and 5.2-6.4% (inter-day, n = 3) for three consecutive days were achieved. Finally, the efficiency of the PT-mu SPE-HPLC-UV method was evaluated for the determination of OAs in human plasma and urine samples with good recoveries (87.3 to 97.8%).

Automated summary

In this study, PVAPAA/CNT-CNC composite nanofibers were prepared and characterized, exhibiting high extraction efficiency for OAs in biological samples. The method showed good linearity, low detection limits, and stable RSDs over three days. The PT-mu SPE-HPLC-UV method was effective for determining OAs in human plasma and urine samples with high recoveries.