Magnetic restricted-access carbon nanotubes for SPME to determine cannabinoids in plasma samples by UHPLC-MS/MS

Jonas Carneiro Cruz; Mariana Azevedo Rosa; Lucas Morés; Eduardo Carasek; José Alexandre de Souza Crippa; Eduardo Costa Figueiredo; Maria Eugênia Costa Queiroz

doi:10.1016/j.aca.2022.340160

Magnetic restricted-access carbon nanotubes for SPME to determine cannabinoids in plasma samples by UHPLC-MS/MS

Anal Chim Acta. 2022 Sep 15:1226:340160. doi: 10.1016/j.aca.2022.340160. Epub 2022 Jul 20.

Authors

Jonas Carneiro Cruz¹, Mariana Azevedo Rosa², Lucas Morés³, Eduardo Carasek³, José Alexandre de Souza Crippa⁴, Eduardo Costa Figueiredo², Maria Eugênia Costa Queiroz⁵

Affiliations

¹ Departamento de Química - Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, 14040-901, Brazil.
² Laboratory of Toxicant and Drug Analyses - LATF, Gabriel Monteiro da Silva St. 700, Federal University of Alfenas - Unifal-MG, 37130-000, Alfenas, MG, Brazil.
³ Departamento de Química - Universidade Federal de Santa Catarina, Florianópolis, 88040-900, SC, Brazil.
⁴ Department of Neuroscience and Behavior, Ribeirao Preto Medical School, University of São Paulo, São Paulo, Brazil.
⁵ Departamento de Química - Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, 14040-901, Brazil. Electronic address: mariaeqn@ffclrp.usp.br.

PMID: 36068070
DOI: 10.1016/j.aca.2022.340160

Abstract

This manuscript describes the development of magnetic restricted-access carbon nanotubes (M-RACNTs) for use as SPME sorbent to determine cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) in human plasma samples by UHPLC-MS/MS. The adsorptive phase was immobilized on an SPME device by electromagnetic interactions between the M-RACNTs and a cylindrical neodymium magnet (3-mm diameter x 8-mm height) attached to a stainless-steel rod (3-mm diameter x 40-mm height). The M-RACNTs were synthesized by incorporating Fe₃O₄ magnetic nanoparticles (MNPs) into commercial carbon nanotubes (CNTs); then the surface of the resulting sorbent was further coated with a layer of bovine serum albumin (BSA). Characterization techniques (SEM, FTIR, and Zeta potential) confirmed the presence of both MNPs and BSA layer dispersed through the structure of the CNTs. The M-RACNTs presented adequate sorption capacity, stable physical/chemical characteristics, and appropriate magnetic properties. Protein exclusion capacity (about 98.5%) was attributed to the chemical diffusion barrier created by the BSA network at the outer surface of the sorbent. The SPME parameters (sample pH, equilibrium time, and desorption conditions) were optimized by design of experiments (fraction factorial planning). The method (validated according to the FDA guidelines) presented adequate selectivity and linearity (coefficient of determination higher than 0.99) at concentrations ranging from the lower limit of quantification (LLOQ) (10 ng mL^-1) to the upper limit of quantification (ULOQ) (300 ng mL^-1) for both CBD and THC. Precision and accuracy varied from 4.47 to 19.84% (LLOQ) and -6.90 to 17.78% (LLOQ), respectively. Carry-over and matrix effect were not significant. The method was successfully applied to determine plasmatic CBD levels in healthy volunteers attending a single session of oral drug administration and THC levels in frequent cannabis smokers.

Keywords: Cannabinoids; LC-MS/MS; Magnetic coating; Magnetic restricted-access carbon nanotubes; Solid-phase microextraction.

MeSH terms

Cannabinoids* / analysis
Chromatography, High Pressure Liquid / methods
Dronabinol / analysis
Humans
Magnetic Phenomena
Nanotubes, Carbon* / chemistry
Solid Phase Microextraction / methods
Tandem Mass Spectrometry / methods

Substances

Cannabinoids
Nanotubes, Carbon
Dronabinol