Porasil®/µPorasil™ Silica Packings  µPorasil, the silica used to prepare the µBondapak bonded phases, is an irregular 10µm particle with a pore diameter of 125? with 325m2/g surface area. A range of different particle size offerings offers the option of scalability for preparative applications with µPorasil column as a QC tool. µPorasil also offers reproducible surface selectivity.      µBondapak C18  µBondapak C18 is a widely used C18 packing. µBondapak C18 is synthesized to form a packing material with high capacity and unique selectivity and surface chemistry. µBondapak C18 columns and cartridges are available in 10µm, 15µm, and 40µm particles packed in a range of steel columns and cartridges for preparative and process applications.      µBondapak Phenyl  µBondapak Phenyl, an alkyl aromatic bonded phase, is less hydrophobic and typically retains compounds for less time than µBondapak C18. The µBondapak Phenyl packing has an 8% carbon load and is fully end-capped. This bonded phase can have a different selectivity than µBondapak C18, particularly for the separation of aromatic compounds.      µBondapak CN  This fully end-capped packing with 6% carbon load is less hydrophobic than µBondapak C18 or Phenyl packings. µBondapak CN typically demonstrates the lowest retentivity in the µBondapak bonded phase family.      µBondapak NH2  The versatile µBondapak NH2 packing can be used for normal phase and ion exchange methods. This amino acid alkyl bonded phase is a weak anion exchanger in aqueous mobile phases. It is typically used with low ionic strength acidic eluents from pH 2.5 to 6.