Fast SPE and HPLC–DAD determination of brucine in human urine using multi-walled carbon nanotubes modified with magnetic nanoparticles

Abstract

A nanomaterial comprising Fe3O4-modified hydroxylated multi-walled carbon nanotubes (Fe3O4–MWCNTs–OH) was prepared by a co-precipitation method. Combined with HPLC-photodiode array detector (DAD), Fe3O4–MWCNTs–OH was used to determine brucine in human urine. Some important parameters that could influence extraction efficiency of brucine were optimized, including the extraction time, amounts of Fe3O4–MWCNTs–OH, pH of sample solutions, desorption solvent and desorption time. Under the optimal conditions, the recoveries of brucine from spiked urine samples were between 93.1 and 104.1%, and the relative standard deviations (RSDs) ranged from 3.1 to 5.7%. The correlation coefficient was 0.9997. The limits of detection and quantification were 6 and 21 ng/mL at a signal-to-noise ratio of 3 and 10, respectively. The results indicated that Fe3O4–MWCNTs–OH combined with HPLC–DAD is a promising solid-phase extraction material for the sample pretreatment in the determination of brucine.