Enter Purchase Order #    The shopping cart contents, for every costumer that visits our site, are saved with a distinct purchase order # in our data base.  These items can be purchased at any time by simply selecting the pay purchase # option from the www.pchemlabs.com home page.  It is very important to understand that our inventory is presented in real-time and is greatly influenced by each item sold. Placing an item on your order form does not reserve that item! Items are always sold on a first purchase basis. Thank you for your order.