Sulfonamide (SA) residues in food of animal origin possess a potential threat to human health and environment. However, due to the polar and ionic characteristics and trace level of SAs and the complexity of food matrices, direct measurement of SAs in these samples is still very difficult. Development of efficient sample pretreatment method for sensitive and selective extraction of trace SAs is of great significance and urgently desired. Therefore, rational design and synthesizing advanced and selective extractants is quite important. In this work, a novel phenazine-based microporous organic network (MON) named TEPM-DP is reasonably synthesized and employed as a packing material for selective solid phase extraction (SPE) and sensitive determination of four typical SAs in milk samples. Phenazine-based monomer with aromatic and heteroaromatic ring and numerous N atoms is chosen to construct TEPM-DP adsorbent to provide π-π, hydrogen bonding, hydrophobic, and electrostatic extraction sites for SAs. The proposed method owns wide linear ranges, low limits of detection, high enrichment factors, and good precisions and recoveries for SAs in complex milk samples. The recoveries of SAs on TEPM-DP are much higher than those of commercial C18 and activated carbon. The extraction mechanisms are also elucidated via FT-IR, XPS, and comparative experiments. This work reports the first example of design and synthesizing phenazine-based MON in SPE via a simple and rapid solvothermal method. The results reveal the great prospects of TEPM-DP for enriching polar and ionic SAs in complex samples and uncover the potency of phenazine-based MON in sample pretreatment, which will promote the development of MON.

中文翻译：

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新型吩嗪基微孔有机网络用于选择性、灵敏地测定牛奶样品中的痕量磺胺类药物


动物源性食品中的磺酰胺（SA）残留对人类健康和环境具有潜在威胁。然而，由于SAs的极性和离子特性以及痕量水平以及食品基质的复杂性，直接测量这些样品中的SAs仍然非常困难。开发高效的样品前处理方法来灵敏、选择性地提取微量SAs具有重要意义和迫切需要。因此，合理设计和合成先进的、选择性的萃取剂显得尤为重要。在这项工作中，合理合成了一种名为TEPM-DP的新型吩嗪基微孔有机网络（MON），并将其用作选择性固相萃取（SPE）和牛奶样品中四种典型SA的灵敏测定的填充材料。选择具有芳环和杂芳环以及大量 N 原子的吩嗪基单体来构建 TEPM-DP 吸附剂，为 SA 提供 π-π、氢键、疏水和静电萃取位点。该方法对复杂牛奶样品中的SAs具有宽线性范围、低检测限、高富集因子以及良好的精密度和回收率。 TEPM-DP 上 SA 的回收率远高于商用 C18 和活性炭。还通过 FT-IR、XPS 和比较实验阐明了提取机制。这项工作报告了第一个通过简单快速的溶剂热方法在 SPE 中设计和合成基于吩嗪的 MON 的例子。研究结果揭示了TEPM-DP在复杂样品中富集极性和离子SAs的巨大前景，并揭示了吩嗪基MON在样品预处理中的潜力，这将促进MON的发展。