Porous membrane-protected molecularly imprinted polymer micro-solid-phase extraction for analysis of urinary cocaine and its metabolites using liquid chromatography – Tandem mass spectrometry

• Published in: Analytica chimica acta 2015-10, Vol.898, p.50-59
• Main Authors: Sánchez-González, Juan, Tabernero, María Jesús, Bermejo, Ana María, Bermejo-Barrera, Pilar, Moreda-Piñeiro, Antonio
• Format: Article
• Language: English
• Subjects: Chromatography, Liquid - methods; Cocaine; Cocaine - urine; High performance liquid chromatography tandem mass spectrometry; Human urine; Humans; Micro-solid phase extraction; Microscopy, Electron, Scanning; Molecular Imprinting; Molecularly imprinted polymer; Polymers - chemistry; Porosity; Porous membrane-protected; Reproducibility of Results; Solid Phase Microextraction - methods; Tandem Mass Spectrometry - methods
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2015.10.002

Porous membrane-protected micro-solid phase extraction (μ-SPE) using a molecularly imprinted polymer (MIP) as an adsorbent has been proposed as an integrated extraction-cleanup procedure for isolating cocaine (COC) and its metabolites [benzoylecgonine (BZE), ecgonine methyl ester (EME), and cocaethylene (CE)] from human urine. MIP beads have been synthesized using COC as a template molecule, ethylene dimethacrylate (EDMA) as a functional monomer, divinylbenzene (DVB) as a cross-linker, and 2,2′-azobisisobutyronitrile (AIBN) as an initiator. High performance liquid chromatography – tandem mass spectrometry (HPLC-MS/MS) has been used for quantifying the analytes after MIP-μ-SPE. Variables such as urine pH, adsorption temperature and time, mechanical (orbital-horizontal) stirring; and composition of the eluting solution and eluting time, were evaluated. The proposed method was shown to be precise and accurate [relative standard deviations (RSDs) of intra- and inter-day tests ranging from 3 to 8% and from 2 to 10%, respectively]; and analytical recoveries in the range of 89–100%). In addition, excellent accuracy was also verified after analyzing a FDT +25% control material for BZE. The detection limits were in the range of 0.16–1.7 ng L−1, low enough for confirmative conclusions regarding cocaine abuse. The method was finally applied for screening/quantifying cocaine and metabolites in urine samples from poly-drug abusers. [Display omitted] •Molecularly imprinted polymer (MIP) for cocaine recognition in urine samples.•μ-SPE device based on porous membrane-protected containing MIP.•Fast cocaine and metabolites determination by reverse phase HPLC-MS/MS.•Limit of quantification lower than the cut-off values for cocaine abuse confirmation.