Poly-3,4-ethylenedioxythiophene nanoclusters for high effective solid phase extraction.

Solid phase extraction (SPE) has emerged as the widely used technique for sample preparation in the analytical process. Recent research trends of SPE are toward developing novel adsorbents to enrich the analytes simply and effectively. In this study, we proposed the poly-3,4-ethylenedioxythiophene (PEDOT) nanoclusters as the SPE adsorbent. During the application, only a small amount of PEDOT nanoclusters was needed and placed in a pipet tip with glass wool on either side. Without complex preparation, the target analytes could be directly extracted from the sample onto the extraction material and eluted in this lab-in-a-pipet-tip system. The efficiency of this approach was demonstrated by detecting 20 kinds of sulfonamides (SAs) in honey with ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). All the analytes were detected by multiple reaction monitoring (MRM) mode. The established method was extensively validated by determining the linearity (R(2)≥0.991), average recovery (88.4-105.0%) and precision (relative standard deviation ≤9.60%). Low detection limits (0.5-4 μg kg(-1)), wide linearity (10-250 μg kg(-1)) and short sample pretreatment time (20 min) were achieved under the optimized conditions. The absolute recoveries of the SAs at high level ranged from 71.1% to 91.4%. Due to its simplicity, selectivity and sensitivity, our new method has potential applications in quantitative analysis of the target compounds in complex samples.