Parse string builder in to csv file as a columns not in a single tab

if (objDataTable != null && objDataTable.Rows.Count > 0)
                {
                    StringBuilder sb = new StringBuilder();
                    foreach (DataColumn col in objDataTable.Columns)
                    {
                        sb.Append(Constants.DataQualifierForCSVFile + col.ColumnName + Constants.DataQualifierForCSVFile + ",");
                        sb.Remove(sb.Length - 1, 1);
                    }
                    sb.Append("\r\n");

                    foreach (DataRow row in objDataTable.Rows)
                    {
                        for (int i = 0; i < objDataTable.Columns.Count; i++)
                        {
                            sb.Append(Constants.DataQualifierForCSVFile + row[i].ToString() + Constants.DataQualifierForCSVFile + ",");
                            sb.Remove(sb.Length - 1, 1);
                        }
                        sb.Append("\r\n");

                    }

                    File.WriteAllText(filename, sb.ToString());
                }