Preparation of monolith-based adsorbent containing abundant functional groups for field entrapment of nitrogen and sulfur containing aromatic compounds in environmental aqueous samples with portable multichannel in-tip microextraction device

Field sample preparation is important and interesting for analysis of nitrogen and sulfur containing aromatic compounds (N,S-CACs) in environmental aqueous samples. In this connection, a new functional groups-rich adsorbent based on porous monolith (ABM) was fabricated by in-situ copolymerization of allylaminocarbonylphenyl boronic acid/styrene and ethylene glycol dimethacrylate. The prepared ABM was employed as the extraction medium of homemade portable multichannel in-tip microextraction device (PMMD) for on-site entrapment of N,S-CACs in various waters. Because of the abundant functional groups, the obtained ABM/PMMD exhibited satisfactory capture capability towards studied N,S-CACs, and the enrichment factors varied from 454 to 491. Under the optimized fabrication conditions, adsorption and desorption parameters, the developed ABM/PMMD was used to field capture investigated N,S-CACs and followed by quantification with high performance liquid chromatography. The limits of detection were in the ranges of 0.00030-0.0016 µg/L. Recoveries with low, medium and high spiked contents located in the range of 82.1-118% with good repeatability (RSDs<9%). In addition, traditional laboratory sample pretreatment approach was employed to verify the reliability of the established method. Results well evidenced that the practicability of introduced ABM/PMMD in the field sample preparation of N,S-CACs in environmental waters.

Facile fabrication of functional groups-rich sorbent for the efficient enrichment of aromatic N- and S-containing compounds in environmental waters

Extraction strategy is designed for the pretreatment of low contents of aromatic N- and S-containing compounds (ANSCs) in environmental waters prior to chromatographic analysis. To enrich studied ANSCs effectively, poly (9-vinylanthracene/4-vinylphenylboronic acid-co-ethylene dimethacrylate/divinylbenzene) polymeric monolithic sorbent were facilely fabricated using the one-step free radical polymerization. Various technologies were employed to investigate the structure and morphology of the resultant monolith. Combining with solid-phase microextraction format, the sorbent exhibited satisfying concentrated performance for ANSCs through multiply interactions under the optimized conditions. After desorption with eluent, the retained analytes were analyzed by HPLC. Results showed that the extraction efficiencies ranged from 51.6 to 93.2%. The linear ranges and limits of detection were 0.01-150 μg/L and 0.63-2.64 ng/L, respectively. Furthermore, the precisions were all below 10%. The introduced approach was productively practiced on three real water samples for simultaneous quantification of studied ANSCs, and the fortified recoveries ranged from 81.5 to 118%. All the results well evidenced that prepared sorbent can enrich ANSCs effectively and the introduced method is reliable alternative for routine analysis of ANSCs in environmental waters.

Application of Ni:ZnS nanoparticles loaded on magnetic multi-walled carbon nanotubes as a sorbent for dispersive micro-solid phase extraction of phenobarbital and phenytoin prior to HPLC analysis: experimental design

Ni:ZnSNPs loaded on magnetic MWCNTs are introduced for dispersive micro-solid phase extraction for the first time.