Evaluation of Monolithic Packed 96‐Tips for Solid‐Phase Extraction of Local Anesthetics from Human Plasma for Quantitation by Liquid Chromatography Tandem Mass Spectrometry

Abstract

Polypropylene 96‐well tips packed with a chemically bonded monolithic methacrylate plug as sample adsorbent were used for solid‐phase extraction (SPE) of ropivacaine and bupivacaine in human plasma samples. Monolithic packed 96‐tips are a miniaturized, solid-phase extraction. Packed 96‐tips require some microliter volumes of solvent (50–100 µL) for elution. Using packed 96‐tips, a 96‐well plate could be handled in about 2 minutes. The key aspect of the monolithic phase is that monolithic material processes both high binding capacity and low back‐pressure properties. The validation of the methodology showed that the accuracy values of quality control samples were between 101 and 118%, while the precision ranged from 4% to 17%. The standard calibration curves were obtained within the concentration range 2–2000 nM in plasma samples. The coefficients of determination (R2) for plasma samples were between 0.984 and 0.999.