Step:1 

       for(int i = 30; i < Type.Count(); i++)
                    {               

                            //Get Item Name
                            string itemName = ItemName[i];                     

                            sb.Append("<row ItemName='" + itemName + "'/>");

                            break;
                        }
                    }
                }

                sb.Append("</root>");

               //Insert Method
               Place your insert method here and pass sb.Tostring() as parameter

                using(ItemInfo item = new ItemInfo())
                {
                    item .InsertItems(sb.ToString());
                }
-------------------------------------------------------------------------------------------------

Step :2

Please add following Query into your Sql stored procedure
CREATE PROCEDURE [dbo].[InsertItems]
	-- Add the parameters for the stored procedure here
		@xml xml
		
AS
BEGIN
	-- SET NOCOUNT ON added to prevent extra result sets from
	-- interfering with SELECT statements.
	SET NOCOUNT ON;

    -- Insert statements for procedure here
	INSERT INTO Items
	(		
		ItemName		
	)
	SELECT            
            TempSwot.Item.value('@ItemName', 'VARCHAR(150)')            
    FROM @xml.nodes('/root/row') AS TempSwot(Item)
END

Now its inserted Bulk amount of data at single attempt..