Sensitivity Enhancement in Capillary Electrophoresis Using Magnetic Particles as Solid-Phase Extraction Sorbents for the Determination of Drugs of Abuse in Urine

: Over the last few years, different types of magnetic particles have been investigated and successfully used in sample preparation, of which iron oxides are the most popular, due to their low price and low toxicity. For analytical purposes, these particles have always been modified and functionalized with different materials to improve their stability and introduce new surface properties. Here we describe the preparation of silica-coated iron oxide particles functionalized with C18 and their application as solid-phase extraction sorbents coupled in-line with capillary electrophoresis for determining drugs of abuse in human urine.