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Simple procedure for determination of the carbon content in silica-supported materials

A simply and accurate analytical method was developed to determination the carbon content in silica-supported materials. The principle of this method was to oxidize sample by a strong oxidant like potassium dichromate to produce carbon dioxide and this gas is absorbed into an alkaline solution for subsequent titration. | Science & Technology Development, Vol 19, No.T5-2016 Simple procedure for determination of the carbon content in silica-supported materials Nguyen Tien Giang Hoang Hanh Uyen Nguyen Khac Manh Nguyen Huy Du Nguyen Anh Mai University of Science, VNU-HCM (Received on 30th June 2015, accepted on 2nd December 2016) ABSTRACT A simply and accurate analytical method was developed to determination the carbon content in silica-supported materials. The principle of this method was to oxidize sample by a strong oxidant like potassium dichromate to produce carbon dioxide and this gas is absorbed into an alkaline solution for subsequent titration. The repeatability and the recovery of this method fell into the required range (% RSD <1.3 % and 98102 % in recovery) of AOAC International. The chloride content of up to 100 mg did not give any influence. The developed procedure was applied to determine the carbon content in octadecylmodified silica samples. Keywords: Carbon, wet oxidation, silica-supported materials INTRODUCTION Currently many silica-supported materials are widely used in various applications [1-3]. To evaluate characterizations of the material, its compositions are usually determined. Of elements to be determined, carbon is the most popular since it presents in all organic compounds. Methods of sample combustion for determination the carbon content have been developed since 1970s with high recovery and repeatability. The principle was to oxidize carbon compounds to produce carbon dioxide and capture it in an absorbent towards weight or volumetric methods [4-6]. So far, modernly instrumental methods have been applied to carbon analysis such as NMR or using elemental analysis technique. These methods are rapid and accurate, however their tremendous disadvantage is too expensive to equip for all laboratories. Trang 162 In this work a method of wet combustion for determination of the carbon content in silicasupported materials was developed .