Magnetic material based on mesostructured silica functionalized with 𝛽-cyclodextrin to extract opium alkaloids in poppy seed infusions

Abstract

Sample preparation methods tend to be fast, simple, with the use of new adsorbents and with lower amounts of organic solvents to make them more environmentally friendly. In this work, a magnetic solid-phase extraction (MSPE) protocol for the quantification of six opium alkaloids (OAs) in poppy seeds infusions has been optimised followed by analysis with liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). For this purpose, a mesostructured silica magnetic composite with β-CD (Fe3O4@SiO2@mSiO2@β-CD) was synthesised and characterized. To obtain the highest level of functionalisation, three proportions of β-CD monomer/material (12.5, 25 and 100%) were determined, demonstrating that 25% showed the highest level. Adsorption studies were carried out in water at different pH (1, 2, 7, 9 and 11) and times (1, 5, 10 and 20 min), confirming the high adsorption capacity at pH 9 for 1 min. Then, the elution conditions of MSPE procedure were optimised (50 mg material, 2 mL of water/EtOH at 50% with 1% formic acid for 1 min). The methodology was successful validated with low detection and quantification limits, negligible matrix effect and good recovery values (89–94%). The methodology was applied to analysis of home-made infusions with four different poppy seeds, observing in one of them a worrying amount of OAs which imply a content in the seeds of at least four times that of the legislation.