The Acclaim^® PolarAdvantage II (PA2) is a polar-embedded column designed for enhanced hydrolytic stability at low and high pH (1.5–10). As a result of the proprietary bonding chemistry, the Acclaim PA2 not only provides you with the flexibility to analyze both polar and nonpolar analytes on a single column as does the Acclaim PA, but it exhibits selectivity complementary to the Acclaim PA, providing you with an additional tool to optimize your separation. Features of the Acclaim PA2 include:

• Single-run analysis of polar and nonpolar analytes
• Hydrolytically stable (pH 1.5–10)
• Rugged column with high efficiency, symmetrical peak shapes even with basic and acidic compounds
• Compatible with 100% aqueous mobile phases
• High reversed-phase capacity with selectivity complementary to conventional C18 columns
• LC/MS compatible

Acclaim PA2 columns feature a polar-enhanced stationary phase. This phase consists of a C18 functional group bonded to the surface of ultrapure silica using a proprietary linkage. The unique chemistry of this polar-embedded phase provides excellent peak shapes for both basic and acidic compounds with a polarity, hydrophobicity, and selectivity complementary to conventional C18 phases and the Acclaim PA. The advantage is that if the selectivity of your C18 method is inadequate for the separation, the Acclaim PA2 could provide the separation you are looking for.

The Acclaim PA2 columns are compatible with 100% aqueous mobile phases, overcoming many of the limitations of conventional C8 and C18 reversed-phase columns. Because of their high solubility in water, many polar analytes are retained on reversed-phase columns only when the organic content of the eluent is very low. Conventional reversed-phase columns are unstable under these conditions and rapidly lose their ability to retain analytes.

Another feature of the Acclaim PA2 columns is their stability under extended pH conditions. Although it is common to analyze polar analytes under low-pH conditions to reduce tailing of amine-containing compounds, under these conditions the lifetime of most conventional and many polar-embedded phases is greatly reduced due to cleavage of the bonded phase. The proprietary bonding of the Acclaim PA2 column resists hydrolytic attack by protecting the bonded phase at low pH. Because mass spectrometry (MS) applications typically add modifiers such as TFA or acetic acid to the mobile phase, the stability of the Acclaim PA2 at low pH makes it an ideal choice for LC/MS applications.

 In addition to low pH stability, although it is common to analyze basic compounds under high-pH conditions to reduce peak tailing, most polar-embedded phases are even less hydrolytically stable than conventional C18 columns.  The Acclaim PA2 is specifically designed to withstand high pH conditions, making it the ideal choice for the separation of both basic and acidic analytes.

To meet the exacting needs of our customers, each Acclaim column is manufactured to stringent specifications to ensure column-to-column reproducibility. Each column is shipped with a lot validation sheet showing the test results and specifications for the lot of bonded silica packed into the column and an individual test chromatogram validating performance. The lot validation includes a chromatography-based metals test and tests for polar selectivity, hydrophobic steric selectivity, and base asymmetry. Production columns are individually tested for capacity and efficiency, and closely monitored for metals contamination. Reproducible column-to-column manufacturing, the use of ultrapure silica, and performance validation of every column prior to shipping, all ensure that the quality of your separations will be maintained month to month and year to year.