Halo Column packings

Halo™ column packings are not made the typical way. Instead, the particles packed into HALO columns are manufactured using Fused-Core™ particle technology that was specially developed to deliver hyper-fast chromatographic separations while avoiding the reliability issues so often associated with fast HPLC. 

The shorter diffusion path of HALO particles reduces axial dispersion of solutes and minimizes peak broadening. A Halo particle has only a 0.5 µm diffusion path compared to the approximately1.5 µm diffusion path of a 3 µm totally porous particle. Because of the shorter diffusion path, the performance advantages of HALO become even more apparent when separating larger solute molecules and operating at faster mobile phase flow rates.

Their ability to generate hyper-fast separations comes not only from their small particle size (2.7 µm) but also from the unique Fused-Core particle technology that creates a 0.5 µm porous shell fused to a solid core particle. As you increase mobile phase flow rate to speed-up a separation, the slow mass transfer of solute molecules inside the particles can limit resolving power. Fused-Core particle technology addresses this limitation by providing an incredibly small path (0.5 µm) for diffusion of solutes into and out of the particles, thereby reducing the time solute molecules spend inside the particles and minimizing a major barrier to fast chromatographic separations.

HALO columns deliver over 50% more separating power (plates) than columns of the same length packed with 3.5 µm particles and more than twice the separating power of columns packed with 5 µm particles.

Note: N/Meter values were calculated at the optimum mobile phase linear velocity for each of these stationary phases. Naphthalene was used as the test probe and the mobile phase conditions used were 60% acetonitrile and 40% water at 24 °C.

Halo columns deliver over 50% more separating power (theoretical plates) than a column of the same length packed with 3.5 µm particles and more than twice the plates of a column packed with 5 µm particles. And, because of Fused-Core particle technology, HALO columns maintain their resolving power at high flow rates. This means that shorter columns and higher flow rates can be used to achieve remarkably fast high resolution separations.

Halo particles give you all of that separation power without the back pressure seen in sub 2micron columns. In fact, the Halo particle operate well within the range of typical 400 bar HPLC systems, not requiring you to purchase the expensive ultra-high pressure instruments and develop new laboratory protocols. Halo columns can turn almost any HPLC system into a high speed workhorse.

Most HPLC systems have operating pressure limits of 6,000 psi (400 bar), or less. As the column packing particle size decreases, the column back pressure increases rapidly. To use columns packed with sub-2 µm size particles at their optimum flow rate, pressure that exceeds 6,000 psi is often encountered. This necessitates purchasing very expensive "ultra-pressure" equipment to achieve optimum performance. HALO columns, even though they do generate slightly higher back pressure than columns packed with 3.5 µm particles, can be used with most existing HPLC equipment.

Copyright 2006 Advanced Materials Technology