m R.N.A. VACCINE production like other biopharmaceutical need various purification stages in the manifacturing process. In this process are used technique like: T.F.F., tangential flow filtration followed by different chromatografic procedure (affinity and ion exchange separation) with various kinds of resin an then UF/DF technique. (ultrafiltration -diafiltration). So it is of interest to verify the material used for this kind of procedure as solid phases or for the membrane and if released impurity in the final product. For Silica-based Reversed-Phase packings, a carbon load percentage indicates the amount of functional bonded phase attached to the Silica-base material. Aim of this work is to investigate the role played by this characteristics in the separation process of m R.N.A. Because this parameter influence the retention time it is interesting to evaluate the use in separation technique of biophramaceutictals.And this also for the carbon coated silica colums. Silica gel for chromatography can be produced by systetic process bu also form Rice treated at high temperature. What kind of effect can be played using an high level of carbon coated silica material?