Application of carbon nanosorbent for PRiME pass-through cleanup of 10 selected local anesthetic drugs in human plasma samples

- The PRiME pass-through cleanup procedure using Mag-CG and Mag-CCNTs as sorbents has been developed.
- It is effective to remove matrix interference for 10 local anesthetic drugs in human plasma.
- The proposed sample preparation procedure is environmental friendly, less time and solvent-consuming.
- LOQs are significantly lower than other reported LC-MS/MS-based methodologies.
- The method is efficient and promising for the applicability to clinical studies.

A novel PRiME (process, robustness, improvements, matrix effects, ease of use) pass-through cleanup procedure has been developed to improve the existing commercially available designs. Carbon nanosorbents, i.e., magnetic modified carboxyl-graphene (Mag-CG) and magnetic modified carboxyl-carbon nanotubes (Mag-CCNTs), have been synthesised and evaluated in PRiME pass-through cleanup procedure for human plasma prior to analysis of 10 selected local anesthetic drugs by liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS). The matrix effect, an interesting phenomenon of ion suppression for local anesthetic drugs containing ester group and ion enhancement for other drugs containing acylamino group, has been minimized using carbon nanosorbents PRiME pass-through cleanup procedure. Under the optimal conditions, the obtained results show higher cleanup efficiency of the carbon nanosorbents with recoveries between 70.2% and 126%. Furthermore, the carbon nanosorbents are also evaluated for reuse up to 80-100 times. The limits of quantification (LOQs) for local anesthetic drugs are in the range of 0.024-0.15 μg/L. Validation results on linearity, specificity, accuracy, and precision, as well as the application to the analysis of lidocaine in five patients recruited from the lung cancer demonstrate the applicability to clinical studies.

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