| HALO HPLC Columns for UHPLC on "standard" instrumentation | |
The HALO column allows the fast separation as in UHPLC but at "normal" pressure under 400 bar on standard HPLC instruments. The fast separation is achieved by smaller size particles packed into the column which reduces the diffusion of solutes into and out of the stationary phase and therefore reduces peak broadening. This allows faster flow rates, fast separations and higher sample throughput. Unfortunately the smaller particles increase back pressure excessively and "fast" columns with 1.7 µm particles usually require expensive ultra-high pressure instrumentation. |
A 0.5 μm porous shell is fused to a solid core particle of ø 1.7 µm. The shorter diffusion path of HALO particles reduces axial dispersion of solutes and minimizes peak broadening. A Halo particle has a diffusion path of only 0.5 μm compared to the approximately 1.5 μm diffusion path of a 3 μm totally porous particle. This allows faster flow rate. Because of the increased separation power of the HALO column, it can either be used for faster analysis or an improved separation. |
| The shorter diffusion path of HALO reduces axial dispersion | |
The shorter diffusion path of HALO particles reduces axial dispersion of solutes and minimizes peak broadening. 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. |
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| HALO Columns have a higher efficiency | Comparison of column back pressure |
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| Van Deemter plots are a convenient way to compare the efficiency of HPLC columns. In this comparison we see that HALO columns are more efficient than columns packed with totally porous particles and that they can be run at higher mobile phase linear velocity and still maintain their resolving power. | Most HPLC systems have operating pressure limits of 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 both UHPLC and conventional HPLC equipment. |
| Peak tailing due to trace metals or silanol groups is essentially nonexistent on HALO stationary phases. The examples here show the excellent peak shape that can be achieved for either bases or acids when using a HALO column. | The conditions used for the bases were chosen to encourage any potential silanol interference. Note the excellent peak shape for amitriptyline under these conditions. |
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Sample: Column: HALO C8, 4.6 x 50 mm Mobile Phase: 75% Methanol, 25% 25 mM Potassium Phosphate, pH 7.0 Flow Rate: 1.5 ml/Min Temperature: ambient (24 °C) Pressure: 3,000 psi, 205 bar |
When applications from 5 µm Material are run on a HALO Column the flow rate needs to be adjusted otherwise the back pressure increases too much. This Quick Tips Guide contains a conversion guide for adjusting the flow rate. |
|
 HALO Cataloguepdf 1.0 MB |
 HALO Brochure Short version of Catalogue listing all available HALO Columns pdf 975 KB |
Evaluation Report "HALO C18 Column
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HALO RP-Amid Phase for the separation of Analytes that form weak hydrogen bridges with Amide. This Phase is an alternative to C18 Phase for Analytes, when a C18 or C8 phase fails to provide an adequate separation. In general, acids will be retained more, bases will be retained slightly less, and neutral analytes will have approximately the same retention on the HALO RP-Amide as they will on the HALO C18. |
HILIC, or hydrophilic interaction liquid chromatography, is especially suitable for separating polar compounds. HALO HILIC columns can be particularly useful for separating acidic and basic compounds that are either not retained or poorly retained on reversed-phase columns. In addition, the complementary selectivity of HILIC may provide a better separation than that achieved by reversed-phase. |
HALO PFP is compatible with highly aqueous mobile phases to facilitate the retention and separation of polar compounds. |
The 160 Angstrom pore size of the Fused-Core particles used in HALO Peptide ES-C18 columns was specifically selected to provide an optimum pore size for separating peptides. Typically, the mobile phase pH will be 2 or less and elevated column temperatures are commonly used to improve reproducibility and resolution. Unfortunately, these conditions hasten the loss of bonded phase and shorten column lifetime. HALO Peptide ES-C18 columns avoid the problem of bonded phase loss through the use of sterically protecting bonding technology that inhibits acid hydrolysis of siloxane bonds, even under extremes of high column temperature and low mobile phase pH. |
for the fast separation of Aromates |
Brochure |
detailed Description |
The HALO Column is based on the Fused-Core particle technology.
HALO RP-AMIDE
UHPLC separation of polar an nonpolar substances
UHPLC separation of Peptides
HALO PHENYL-HEXYL
Application Notes |
|
 Separation of Explosiveson HALO C18 pdf 684 kb |
 Rapid Isocratic Separation of Fibrates on HALO C-18 Phasepdf 782 kb |
 Separation of Structurally Similar Steroids on HALO C18 and PFPpdf 766 kb |
 Isocratic Separation of Dinitrotoluenes on HALO PFP Phasepdf 713 kb |
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 Isocratic Separation of Amphenicols on HALO Phenyl-Hexyl Phasepdf 827 kb |
 Separation of Benzodiazepines on HALO Phenyl-Hexyl, C18, and PFP Phasespdf 856 kb |
 Seperation of Peptides and Small Proteins on HALO Peptide ES-C18pdf 729 kb |
 Separation of Carbamate Pesticides on HALO ES-CN Phasepdf 786 kb |
 Isocratic Separation of Phenyl Ureas on HALO ES-CN pdf 819 kb |
 Separation of 5 Beta Blocker Drugs on HALO Penta-HILICpdf 868 kb |
 Separation of Antiulcer Drugs on HALO Penta-HILICpdf 840 kb |
EXP = Extreme Pressure Chromatography |
HALO UHPLC Guard Columns protect the column physically (filtration) and chemically without affecting the fast separation of the column. Exchanging the cartridge is easy and does not require any tools. |
EXP Fittings
easy to use thanks to EXP Holder and Cartridge with ultra-low internal swept volume and |
OPTI-TRAP EXP™ The EXP Cartridge System enables chemists to quickly remove detergents or salts which can affect the ionization process in MS work. This trapping technique can concentrate the sample directly on-line, allowing for increased recovery of precious sample material compared to off-line techniques. On-line trapping readily lends itself to automation for high-throughput analysis in UHPLC/MS applications. |
Bed volumes from 4 - 100 µl are available. The cartridges are available with the 2.7 µm HALO Fused Core Phase Materials C18, C8, HILIC, RP-Amide and Phenyl-Hexyl as well as C4, SAX and SCX. OPTI -TRAP EXP™ Trap Columns with HALO® for UHPLC Applications OPTI - PAK® EXP™ Stem Traps with HALO® for UHPLC Applications |
OPTI-GUARD® 
EXP titanium/PEEK hybrid ferrule offering repeated zero-dead-volume connections, hand-tight to 600 bar or wrench-tight to 1,400+ bar. 