Recuperação de sílica gel utilizando tratamento oxidativo

Abstract

Silica gel is a synthetic amorphous silica widely used in laboratory techniques for separating components from substances. It is considered a highly adsorbent, non-toxic, chemically inert and stable compound; characteristics that make it an excellent resource to be used as a stationary phase in chromatographic analysis in the medical, pharmaceutical, chemical and biological fields. This work seeks to apply methodologies that promote the recovery of residual silica gel, previously used in procedures for purification and separation of organic compounds in the laboratories of the Universidade Tecnológica Federal do Paraná (UTFPR). Samples of the material were subjected to an oxidative treatment with hydrogen peroxide in order to promote the degradation of the organic compounds present. Hydrogen peroxide is one of the most used oxidizing agents nowadays due to the ease with which it can be converted into hydroxyl radicals. As a method of comparing the effectiveness of material recovery, the samples were submitted to chromatographic analysis of retention time using Methyl Orange as indicator and ethanol as mobile phase. Compared to the reference sample, which is new silica, the recovered material did not obtain the same parameters, showing significantly shorter retention times. However, its behavior in relation to packaging in the liquid chromatography column was regular, which makes its use in laboratory practical classes of demonstrations of the methodology of assembly and operation of chromatographic columns a viable possibility for the disposal of the material, thus avoiding its disposal.