General, chemical type or category of compound to be separated.
The type of resin that is packed inside the column tube.
United States Pharmacopeia HPLC column designation.
Size (in micrometers) of the polymer or silica bead packed inside the column tube.
Inside diameter (in millimeters) of the column tube.
Length of the column tube (in millimeters).
The Stable Alternative to C8 or C18 Columns
PRP-1 Columns are beneficial in a number of ways:
Wide pH Stability
Good Sample Recovery
Sample Recovery is vital to sample purification efforts. Problems arise when labile sample become irreversibly attached to the silanol groups present on C8 and C18 columns. Since PRP-1 is made entirely of poly(styrene-divinylbenzene), there are no silanol groups to cause sample loss. Thus, the recovery and quantitation of labile and reactive samples is enhanced. The purification of protected oligonucleotides demonstrates the enhanced recovery possible with PRP-1columns. While C18 columns typically recover only 50-80% of oligonucleotides, PRP-1 columns provide recoveries greater than 95%. Application #26 illustrates the purification of a crude 5'-DMT 36mer with excellent recovery.
Consistent ReproducibilityHamilton PRP-1 reversed phase columns are ideal for applications that require a high degree of column-to-column and batch to batch consistency (i.e., quality assurance, clinical trials). Unlike C8 or C18 columns, PRP-1 has no stationary phase coating. The integral reversed phase characteristics of the PRP-1column obviates the need for special coating techniques. Since there is no stationary phase to hydrolyze, the column maintains its performance characteristics longer than many C8 or C18 columns. While many column manufacturers rely on other sources for their raw silica support, Hamilton manufactures its PRP-1support, thus assuring you of a consistent supply of PRP-1columns.
Easy Sample Scale-up
PRP-1 is available in 5, 7, 10, and 12-20 µm particle sizes. Columns are available prepacked and tested in a variety of sizes, varying from analytical to semi-prep and preparative scale. Consistent packing material allows linear method scale-up. Simply increase the sample size and flow rate. The capacity of a 21.5 mm ID preparative column is 27 times that of an analytical column with a 4.1 mm ID.
Long Life (Excellent Durability)PRP-1columns are packed with a poly(styrene-divinylbenzene) material. This support is pressure stable up to 5,000 psi, and cross-linked to prevent shrinkage or swelling (common in other polymeric columns). Since the support is entirely polymeric with no silica to deteriorate, column lifetime is longer for PRP-1 than silica C4, C8 or C18 columns. Regardless of whether you use ion-pair reagents or high percentage aqueous buffers (80-100%) for your separation, PRP-1columns outlast silica-based columns under most HPLC conditions. An example of this longevity is the purification of crude protected oligomers (see Application #26). PRP-1columns will last approximately one year, while C8 and C18 columns will last only 3-4 months.
The following list of example application chromatograms illustrate a few of the applications (from alcohols to vitamins) that are possible with PRP-1 reversed phase columns. The polymeric PRP-1 support allows the separation of compounds that normally coelute. Application #18 illustrates the separation of chloramphenicol base from the 1 and 3 succinate. These compounds coelute on other columns. The pH stability of the PRP-1columns allows samples to be analyzed at basic pH (8.13). Some samples show a dramatic increase in their absorbance characteristics at basic pH. Application #14 illustrates a 10 fold increase in the detection of antiepileptics at pH 8.23 versus pH 4.4 (Application #13). Altering the pH of the separation may hot only increase a sample's detectability, but it can also radically alter a compound's retention and the elution order of a sample (see Application #38 and #39). Changes in elution order can be used to determine sample purity and identity.
Polymeric columns for general separations