The major factors in Van Deemter equation that affect chromatographic efficiency are “eddy dispersion, longitudinal diffusion, and resistance to mass transfer”- the A, B, C terms respectively from the equation.Ī-Term: “Multipath effect” (Eddy dispersion):Ī’ Term completely depend on column & only important in liquid chromatography. HETP:-Height Equivalent to Theoretical plate This reduction in band broadening results in chromatographic separations with better resolution, higher sensitivity, and improved peak capacities. With core shell particles, all three sources (A, B & C) are reduced compared to fully porous particles as seen in the graphs below. Why core–shell particles can perform better with low back pressure & improves chromatographic efficiency, in terms of "van Deemter equation"?Ĭore shell technology results in Less Band Broadening, in order to maximize efficiency, sources of band broadening need to be minimized. This highly optimized process combined with uniform particle size distribution produces a column that generates extremely high plate counts. Using sol-gel processing techniques that incorporate nano structuring technology, a durable, homogeneous porous shell is grown on a solid silica core. In terms of size and shape, core-shell particles are remarkably constant, which also helps to enhance separation efficiency by limiting variable analyte movement between the particles.Ĭore-shell particle is not fully porous. In order to increase efficiency, it’s important to minimize sources of band broadening, such as diffusion. This is because diffusion only occurs via the porous, outer layer of the particle rather than the entire particle. Kinetex Core-Shell Technology in the Axia preparative format delivers a performance advantage to customers in pharmaceutical and natural products development, who can now use scalable core-shell solutions from analytical stage UHPLC or HPLC methods to purification.The science behind the core shell columns giving a highly efficient performance in LC-Chromatography.Īlways all chromatographic scientists willing to have fast separation of compounds, results in very high operating pressures, which places a huge burden on chromatographic instruments.Ĭore–shell silica microspheres: with a solid core and a porous shell, also known as fused-core or superficially porous microspheres, have been widely investigated and used for highly efficient and fast separation with reasonably low pressure for separation of small molecules, large molecules and complex samples.Ĭore-shell particles’ high separation efficiency is largely due to more rapid analyte mass transfer – from the mobile phase through to the stationary phase and back again. The Phenomenex patented Axia packing and hardware technology, introduced in 2005, eliminates the drawbacks of traditional slurry packing, delivering uniform bed density and dramatic performance advances. In fact, the 5-micron media provides 60 to 90% higher average efficiencies compared to the same size fully porous columns with little to no method development. “The 30mm columns are now available in C18, XB-C18, C8 and Phenyl-Hexyl phases, and we will be introducing more phases in the near future.”ĥ-micron is the largest particle in the Kinetex core-shell family and delivers better performance than 5-micron fully porous offerings, with no increase in backpressure. “Our range of Kinetex core-shell particle size offerings, including 1.3-, 1.7-, 2.6- and 5-micron, enables exacting scale-up in pharmaceutical applications, eliminating extensive method rework,” explained J.T. The Phenomenex Axia preparative format delivers longer column lifetime, higher efficiencies, improved performance and high reproducibility, compared to conventionally packed columns for lab-scale preparative chromatography. With the addition of this larger diameter column, Phenomenex offers the only core-shell media line that can be used from analytical scale through scale-up to purification. Also offered in a 21.2mm I.D., the new 30mm column enables increased sample loading and throughput. (internal diameter) Kinetex core-shell 5-micron column in Axia™ hardware for preparative HPLC and SFC in pharmaceutical lab-scale purification.
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