Effervescence-Assisted Magnetic Solid-Phase Extraction of Nitroimidazoles and Their Metabolites Using Magnetic Hypercrosslinked Polystyrene

The magnetic hypercrosslinked polystyrene was used for the first time as a sorbent in effervescence-assisted magnetic solid-phase extraction. An effervescent tablet composed of magnetic hypercrosslinked polystyrene, sodium bicarbonate, and citric acid was used for extraction of nitroimidazoles and their metabolites from honey samples prior to their LC-MS/MS determination. In the proposed method, the dispersing of the sorbent occurs without the help of additional energy sources (such as ultrasound and stirring devices) due to the intensive release of carbon dioxide during dissolution of the tablet. The magnetic properties of the sorbent make it possible to separate it without the use of centrifugation or filtration. As a result, the extraction procedure takes only 3 min. The effects of important parameters, including the molar ratio of sodium bicarbonate to citric acid, mass of magnetic hypercrosslinked polystyrene, mass of the tablet, and desorption conditions, were systematically studied. The proposed method was validated using spiked honey samples. Under the optimum experimental conditions, the proposed method provided the limit of detection and limit of quantification of 0.3 and 1 mu g kg(-1), respectively. Precision values expressed as relative standard deviation were < 16% for the intra-day and inter-day experiments. In general, the developed method is simple, fast, resource-efficient, and has good analytical characteristics.