Preparation of a novel monolith-based adsorbent for solid-phase microextraction of sulfonamides in complex samples...

Effective extraction is an essential step in the sensitive and accurate analysis of sulfonamides (SAs) in complex samples. In this study, based on the chemical properties of SAs, a novel monolith-based adsorbent using 4-vinylbenzoic acid and 4-vinylphenylboronic acid as dual-functional monomers was tailored and employed as efficient extraction phase of solid-phase microextraction. Various characterized techniques were applied to investigate the structure and morphology of the obtained adsorbent. Due to the abundant functional groups, the synthetic adsorbent displayed satisfying extraction performance for target SAs through multiple interactions including ion-exchange, B-N coordination, π-π and hydrophobic interactions. Following elution with the desorption solution of methanol/formic acid (98.5/1.5, v/v), the extractive SAs were measured by HPLC-MS/MS. Under the optimized conditions, the proposed approach exhibited wide linear ranges (0.005-10.0 μg/L for most of analytes), low limits of detection (in the range of 0.31-2.3 ng/L) and good precision (RSDs were lower than 8.0%). In the analysis of target SAs in environment waters and honey samples, the recoveries at low, medium and high spiked concentrations were in the range of 83.5-119%, and the RSDs (n = 3) varied from 0.6% to 9.6%. Compared with existing approaches, the current method presents some merits such as high sensitivity, good reproducibility, low consumptions of sample and organic solvent.