Surfactant assisted magnetic dispersive micro solid phase extraction-HPLC as a straightforward and green procedure for preconcentrating and determining Caffeine, Lidocaine, and Chlorpromazine in biological and water samples

Magnetic dispersive micro solid-phase extraction as a proper and selective sample preparation was developed to extract and clean up three drugs, including Caffeine (CAF), Lidocaine (LID), and Chlorpromazine (CPZ), before determining by HPLC-DAD. Nickel-doped BiFeO3 was synthesised using the sol-gel method as a magnetic sorbent core and coated with tetraethyl orthosilicate (TEOS) to enhance the sorbent stability and the sorbent selectivity. In the extraction procedure, the sorbent was dispersed into acetonitrile as disperser solvent and sodium dodecyl sulphate (SDS) as a disperser agent before injecting into the sample solution to extract the analytes. Several influential factors in the method were evaluated using an experimental design strategy. Under the optimum conditions, the method displayed wide linearity in the concentration ranges of 20.8-365, 1.4-389, and 2.7-355 ng mL(-1) to determine CAF, LID, and CPZ with a suitable R-2 between 0.9963 and 0.9971, respectively. Intra-day and inter-day relative standard deviations were in the ranges of 3.5-3.8 and 3.9-4.3%. LODs and LOQs for the determination of CAF, LID, and CPZ were lower than 6.3 and 20.8 ng mL(-1). The method is convenient for determining the analytes in real water and biological samples with RSD (n = 3) and recovery in the ranges of 3.0-4.3% and 87.5-96.9%, respectively.

Automated summary

Magnetic dispersive micro solid-phase extraction method was developed for the extraction and determination of three drugs with wide linearity, low LODs and LOQs, suitable for real water and biological samples.