Rihui Su,Guihua Ruan,Zhengyi Chen,Fuyou Du,Jianping Li
A new class of solid-phase extraction column prepared with grafted mercapto-silica polymerized high internal phase emulsion particles was used for the preconcentration of trace lead. First, mercapto-silica polymerized high internal phase emulsion particles were synthesized by using high internal phase emulsion polymerization and carefully assembled in a polyethylene syringe column. The influences of various parameters including adsorption pH value, adsorption and desorption solvents, flow rate of the adsorption and desorption procedure were optimized, respectively, and the suitable uploading sample volumes, adsorption capacity, and reusability of solid phase extraction column were also investigated. Under the optimum conditions, Pb 2+ could be preconcentrated quantitatively over a wide pH range (2.0–5.0). In the presence of foreign ions, such as Na + , K + , Ca 2+ , Zn 2+ , Mg 2+ , Cu 2+ , Fe 2+ , Cd 2+ , Cl − and NO 3 − , Pb 2+ could be recovered successfully. The prepared solid-phase extraction column performed with high stability and desirable durability, which allowed more than 100 replicate extractions without measurable changes of performance. The feasibility of the developed method was further validated by the extraction of Pb 2+ in rice samples. At three spiked levels of 40.0, 200 and 800 μg/kg, the average recoveries for Pb 2+ in rice samples ranged from 87.3 to 105.2%.
Yongping Gao,Jinlou Gu,Liang Li,Wenru Zhao,Yongsheng Li
Gold nanoshells have shown great potentials in various fields. However, the widely used seed-mediated growth method based on a silica template for gold nanoshells is a complex and time-consuming procedure. In this work, mercaptosilica was first used as a template to synthesize gold nanoshells through improved seed-mediated growth method. It is verified that gold seeds were formed and attached onto the mercaptosilica nanospheres through Brust-like, in situ process, which makes this method extremely time-saving and easy to manipulate. Importantly, the key factors affecting the in situ process were demonstrated, allowing fine control on the synthesis in a highly reproducible manner. The as-synthesized nanoshells are monodisperse with well-defined morphology and tunable near-IR plasmon resonance. Furthermore, other metal nanoparticles such as Pt and Pd could be grafted onto the surface of mercaptosilica nanospheres through the same Brust-like, in situ process. These provide new insights into seed attachment, and the improved seed-mediated growth approach based on Brust-like, in situ seed formation will take an important step forward toward the widespread application of gold nanoshells.
危险品化学品经营许可证（带存储）