Supply Of Magnesium Sulfate Anhydrous (sigma) , Sodium Acetate (sigma) , Psa (sigma) , C-18 (sigma) , Ethyl Acetate For Chromatography (merck) , Ethyl Acetate For Analysis (merck) , Water (hplc Grade) , Acetonitrile (merck) , Methanol (merck) , Nitric Aci (EXPIRED)