Comparison between the efficiencies of sub-2 μm C18 particles packed in narrow bore columns.

The chromatographic performance of two types of core-shell particles and two fully porous particles packed in 2.1 ID × 50 mm columns was investigated. Comparisons of the performances of the EiS-150-C(18) to that of the Kinetex-1.7 μm-C(18), Acquity-BEH-1.7 μm-C(18), and Zorbax-XDB-1.8 μm-C(18) are made and discussed. The physical factors that govern the performance of these columns, such as particle size distribution and column external, total, and particle porosity of the C(18) packing materials were among the prime foci of investigation. The differences in the mass transfer behavior measured using naphtho[2,3-a]pyrene between these columns provides an indication of improved performance of the new EiS-150-C(18) column. The minimum reduced height equivalent to a theoretical plate (HETP) value for the EiS-150-C(18), h(min) = 1.95, was achieved and was comparable to that obtained from the C(18) phases of the Kinetex (h(min) = 2.53), the Acquity (h(min) = 2.26), and the Zorbax (h(min) = 2.57) columns. This study reveals the importance of the dimension of the shell thickness in controlling the performance of columns packed with shell particles in narrow bore columns.