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Synthesis of the reversed stationary phase for solid phase extraction using trimethoxyoctadecyl silane

Octadecyl grafting silica was synthesized using trimethoxyoctadecyl silane. Reaction conditions were optimized so that the carbon percentage of resulted material was similar to that of commercial products. Temperature and catalyst played very important roles in the reaction. The material was also undergone the end-capping process to reduce unreacted silanol groups. | TAÏP CHÍ PHAÙT TRIEÅN KH&CN, TAÄP 19, SOÁ T1 - 2016 Synthesis of the reversed stationary phase for solid phase extraction using trimethoxyoctadecyl silane Nguyen Tien Giang Nguyen Huy Du Nguyen Anh Mai University of Science, VNU-HCM (Received on July 20 th 2015, accepted on March 31 th 2016) ABSTRACT Octadecyl grafting silica was synthesized using groups. Final product owned 14.1 % of carbon trimethoxyoctadecyl silane. Reaction conditions were content and 75 % of the unreacted silanols. Retention optimized so that the carbon percentage of resulted behavior of product was tested and compared to the material was similar to that of commercial products. same noes available on the market. Results showed Temperature and catalyst played very important roles that both resulted material and commercial had the same retention properties. in the reaction. The material was also undergone the end-capping process to reduce unreacted silanol Key words: reversed stationary phase, octadecyl modified silica, alkoxysilane, solid phase extraction INTRODUCTION Solid phase extraction (SPE) is a well-established sample pretreatment technique because it demands less organic solvents and can remove interferences simultaneously. In SPE chemical structure of sorbent materials play a decisive role[1]. Currently, the most popular sorbent material is conventional reversed phase (CRP) on silica support. In the current study, CRP sorbent was synthesized using alkoxyoctadecyl silane and its retention properties were compared with commercial CRPs. CRP is synthesized by directly bonding alkoxyoctadecyl silane or chlorooctadecyl silane onto silica surface[2-5]. While chlorolsilane is very reactive, alkoxysilane is one of the least reactive reagents[3]. However, during the reaction with silica, chlorosilane produces HCl by-product which can damage the main product. For alkoxysilane, the byproduct is alcohol which is harmless and easy to remove in distilled conditions. Besides, the .