The use of L-carbohydrates and their corresponding nucleosides in medicinal application has greatly increased. For example L-ribose has been much in demand as the starting material for curing hepatitis B. High performance liquid chromatography (HPLC) method was studied for the analysis of ribose and arabinose fractions from ion exchange chromatography (IEC). Dowex Monosphere 99 Ca/320 resin was packed in IEC to separate ribose and arabinose under various operating conditions. $NH_{2}$ and sugar HPLC columns were then used to analyze the fractions from the IEC column. Pulse input method (PIM) was also used to measure adsorption isotherms of ribose and arabinose in the Dowex column and HPLC columns. Experimental results and simulations by ASPEN chromatography were compared with fair agreement.