How to remove the Duplicate Records from the Datatable based on Column

 public DataTable RemoveDuplicateRows(DataTable dTable, string colName)
        {

            try
            {
                Hashtable hTable = new Hashtable();
                ArrayList duplicateList = new ArrayList();
                foreach (DataRow dtRow in dTable.Rows)
                {
                    if (hTable.Contains(dtRow[colName]))
                        duplicateList.Add(dtRow);
                    else
                        hTable.Add(dtRow[colName], string.Empty);
                }
                foreach (DataRow dtRow in duplicateList)
                    dTable.Rows.Remove(dtRow);
            }
            catch (Exception ex)
            {
               //
            }
            return dTable;
        }