Trace determination and characterization of ginsenosides in rat plasma through magnetic dispersive solid-phase extraction based on core-shell polydopamine-coated magnetic nanoparticles

Enrichment of trace bioactive constituents and metabolites from complex biological samples is challenging.This study presented a one-pot synthesis of magnetic polydopamine nanoparticles(Fe3O4@-SiO2@PDA NPs)with multiple recognition sites for the magnetic dispersive solid-phase extraction(MDSPE)of ginsenosides from rat plasma treated with white ginseng.The extracted ginsenosides were characterized by combining an ultra-high-performance liquid chromatography coupled to a highresolution mass spectrometry with supplemental UNIFI libraries.Response surface methodology was statistically used to optimize the extraction procedure of the ginsenosides.The reusability of Fe3O4@-SiO2@PDA NPs was also examined and the results showed that the recovery rate exceeded 80%after recycling 6 times.Furthermore,the proposed method showed greater enrichment efficiency and could rapidly determine and characterize 23 ginsenoside prototypes and metabolites from plasma.In comparison,conventional methanol method can only detect 8 ginsenosides from the same plasma samples.The proposed approach can provide methodological reference for the trace determination and characterization of different bioactive ingredients and metabolites of traditional Chinese medicines and food.

MSPE-UPLC-MS/MS测定生活饮用水中呋喃丹、敌敌畏、乐果及马拉硫磷

目的利用合成的磁性碳材料作吸附剂,建立一种快速测定生活饮用水中呋喃丹、敌敌畏、乐果及马拉硫磷4种农药残留量的磁分散固相萃取—超高效液相色谱串联质谱方法(MSPE-UPLC-MS/MS)。方法水样中加入磁性碳材料进行分散固相萃取,在外部磁场作用下弃去溶液后,加入甲醇洗脱,洗脱液过滤膜后经C;柱分离,电喷雾正离子化模式下,以多反应监测(multi-reaction monitoring, MRM)方式检测。结果呋喃丹、乐果和马拉硫磷在(0.10~50.0)μg/L,敌敌畏在(0.20~100.0)μg/L浓度范围内线性良好,分析物线性相关系数r≥0.999 0;方法检出限为(0.017~0.050)μg/L,最低检测质量浓度为(0.06~0.17)μg/L;3个浓度加标回收率为88.0%~105.7%范围内,相对标准偏差为2.0%~12.1%(n=6);磁性材料重复使用10次后依然具有较好的吸附性能。结论本方法简便、高效、准确,可用于生活饮用水中呋喃丹、敌敌畏、乐果及马拉硫磷4种农药残留量的检测。

基于分子印迹磁性复合材料的基质分散-固相萃取/液相色谱法测定海水中的氯酚类污染物

建立了一种快速、高效、灵敏的基质分散-磁性固相萃取/液相色谱（d MSPE-HPLC）方法,用于海水中5种氯酚类（CPs）污染物残留量的测定。样品用五氯酚分子印迹氨基功能化磁性复合材料富集,在C8反相液相色谱柱（250 mm×4.6 mm×5.0μm）上分离,以甲醇-5 mmol/L乙酸铵水溶液（体积比70∶30）为流动相,230 nm处检测。考察了样品p H值、萃取时间和洗脱剂的种类与用量对CPs富集回收率的影响。结果表明,在最佳实验条件下,5种CPs在1~5 000 ng/L浓度范围内呈良好的线性关系,相关系数（r2）均大于0.998 9;平均回收率为86.5%~98.8%,相对标准偏差（RSDs）为0.8%~8.6%;检出限（LODs）为0.18~1.20 ng/L,定量下限（LOQs）为0.6~4.0 ng/L。方法可用于海水中CPs类化合物的快速筛查和确证分析。

石墨相氮化碳材料在样品前处理中的研究进展

作为一种新型非金属材料,石墨相氮化碳以其独特的优点,如简单的制备方法、优良的化学及热稳定性、良好的生物兼容性和无毒性等,受到越来越多的关注。石墨相氮化碳及其复合材料目前已被广泛应用于电催化、光催化、生物成像等领域。由于具有大的比表面积,同时又是富电子的疏水材料,石墨相氮化碳相关材料被认为是一种理想的样品前处理吸附剂。该文探讨了近年来石墨相氮化碳及其复合材料作为固相萃取、分散固相萃取、磁性固相萃取、固相微萃取吸附剂在样品前处理中的应用,并对未来的发展趋势和应用前景进行了展望,以期为相关领域的研究提供帮助。