Facile preparation of boronic acid-functionalized magnetic nanoparticles with a high capacity and their use in the enrichment of cis-diol-containing compounds from plasma.

The use of bronate affinity adsorbents is a new separation method that appeared recently with great potential for specific extraction of cis-diol-containing compounds. In this work,a new strategy for the facile construction of boronic acid-functionalized Fe3 O4 magnetic nanoparticles (Fe3 O4 @FPBA MNPs) with a high capacity was described. The extraction capacity of the Fe3 O4 @FPBA MNPs was determined to be 66.0 ± 2.7 µmol/g for catechol and 80.6 ± 2.0 µmol/g for dopamine, being higher than that for the reported methods. The Fe3 O4 @FPBA MNPs were used to extract four cis-diol drugs: caffeic acid isopropyl ester, caffic acid bornyl ester, isopropyl 3-(3,4-dihydroxyphenyl)-2-hydroxypropanoate and 3-(3, 4-dihydroxyphenyl)-2-hydroxylpropionic acid - from the spiked rabbit plasma, and the recoveries of four drugs were between 87.29 and104.37% with relative standard deviations ranging from 1.34 to 8.81%. Under the most favorable conditions, the solid-phase extraction combined with HPLC-UV for the analysis of four drugs in plasma could eliminate interferences from endogenous components of the biological fluids and exhibited sufficient precision and accuracy. These results showed that the prepared Fe3 O4 @FPBA MNPs were qualified for efficiently enriching and determining the trace cis-diol substances from biological samples.