VOLTEC

ZIRCHROM SEPARATIONS, INC.

Packed Columns | Guard Columns | Application Notes
Testimonials | Home

ZIRCHROM SATISFIED CUSTOMERS

I would recommend that every research scientist have a ZirChrom-PBD column on hand for his/her toughest separations. In our case, we had a very small hydrophilic impurity and a larger very hydrophobic pharmaceutical compound that we needed to separate. The separation on any silica-based column that we tried was poor and not very robust. One of the analytes was completely unretained (even in 100% water) while the other analyte was too well retained. We used the ZirChrom-PBD column with phosphate in the mobile phase as a mixed-mode (reversed-phase/cation-exchange) support that easily separated the two compounds. We were able to manipulate the separation factor through the amount of organic in the mobile phase and/or through a change in the ionic strength of the mobile phase. The final optimized separation was very robust and had a unique selectivity from any other column that was tried. Senior Research Scientist Major Pharmaceutical Company

-------------------------------------------------------------------------------- ZirChrom® -PBD is vastly more stable than any silica-based reversed-phase—at any pH and at any temperature (pH 1-14, up to 200° C). And in contrast to stable polymer reversed-phase (PRP), ZirChrom’s plate count and pressure drops are excellent. The efficiency of ZirChromā -PBD is higher than most commercial silica phases I have used and substantially better than any commercially available alumina-based PBD phases.

Dr. John Blackwell Chirex Inc.
-------------------------------------------------------------------------------- We have had excellent success with ZirChrom-PBD. The separation of diastereomeric esters of Naproxen with occurs with better resolution and faster elution times (7 min vs. 40 min) than any other type of column. In fact, with 3-methylcyclohexen-1-ol, ZirChrom-PBD is the only column that gives separation. Professor John Sowa Seton Hall University Department of Chemistry
-------------------------------------------------------------------------------- After months of HPLC method development work with emamectin, I was out of ideas. I had tried many types of silica-based columns and many different mobile phases, but I could not find a system that would be suitable for scaling up to a preparative level. Every method that I had tested gave me broad, tailing peaks. Even highly endcapped, base-deactivated columns gave poor results. Knowing that the problem was with the NH-CH3 of the hydrophobic emamectin molecule interacting with the Si-OH in the HPLC columns, I started looking for alternatives to silica-based chromatography. That was when I found the ZirChrom web site and read about their zirconia-based PBD column. We purchased an analytical ZirChrom-PBD column, and I was really impressed by the improvement that it made in my chromatography. Although the concept of "tunable selectivity" was new to me, I soon found a system using an ammonium phosphate buffer that gave rapid resolution of the emamectin and sharp, symmetric peaks. Load testing revealed that this column could handle much higher amounts of emamectin than any silica-based column that I had worked with and still give baseline resolution. With the success that we saw with the analytical column, we asked if a preparative HPLC column could be packed with the same 3µm particles. We wanted a column that was the same length as the analytical column (150 mm), but with a larger i.d. so that developed methods could be scaled up directly. Our goal was to find an efficient purification method for synthesized radio labeled emamectin. After working closely with ZirChrom technical support, we ordered a 150 mm x 22 mm i.d. preparative column along with the recommended guard column. The performance of the preparative column was even better than I had expected. We had hoped to be able to run about 10 mg of crude emamectin per injection, but I found that the column could still give baseline resolution when injecting as much as 25 mg. Our original method used a silica-based phenyl column and a multi-step solvent gradient. Using the phenyl column, we could purify 10 mg per run, and each run took 2 ½ hours. With the preparative ZirChrom-PBD column under isocratic conditions, I was able to purify 25 mg of crude emamectin in 30 minutes. The time required to purify 300 mg of crude emamectin was reduced from weeks to a day!

David A. Hunt
Analytical Chemist
Novartis Crop Protection

Packed Columns | Guard Columns | Application Notes
Testimonials


	ZIRCHROM SEPARATIONS, INC. Packed Columns \| Guard Columns \| Application Notes Testimonials \| Home ZIRCHROM SATISFIED CUSTOMERS I would recommend that every research scientist have a ZirChrom-PBD column on hand for his/her toughest separations. In our case, we had a very small hydrophilic impurity and a larger very hydrophobic pharmaceutical compound that we needed to separate. The separation on any silica-based column that we tried was poor and not very robust. One of the analytes was completely unretained (even in 100% water) while the other analyte was too well retained. We used the ZirChrom-PBD column with phosphate in the mobile phase as a mixed-mode (reversed-phase/cation-exchange) support that easily separated the two compounds. We were able to manipulate the separation factor through the amount of organic in the mobile phase and/or through a change in the ionic strength of the mobile phase. The final optimized separation was very robust and had a unique selectivity from any other column that was tried. Senior Research Scientist Major Pharmaceutical Company -------------------------------------------------------------------------------- ZirChrom® -PBD is vastly more stable than any silica-based reversed-phase—at any pH and at any temperature (pH 1-14, up to 200° C). And in contrast to stable polymer reversed-phase (PRP), ZirChrom’s plate count and pressure drops are excellent. The efficiency of ZirChromā -PBD is higher than most commercial silica phases I have used and substantially better than any commercially available alumina-based PBD phases. Dr. John Blackwell Chirex Inc. -------------------------------------------------------------------------------- We have had excellent success with ZirChrom-PBD. The separation of diastereomeric esters of Naproxen with occurs with better resolution and faster elution times (7 min vs. 40 min) than any other type of column. In fact, with 3-methylcyclohexen-1-ol, ZirChrom-PBD is the only column that gives separation. Professor John Sowa Seton Hall University Department of Chemistry -------------------------------------------------------------------------------- After months of HPLC method development work with emamectin, I was out of ideas. I had tried many types of silica-based columns and many different mobile phases, but I could not find a system that would be suitable for scaling up to a preparative level. Every method that I had tested gave me broad, tailing peaks. Even highly endcapped, base-deactivated columns gave poor results. Knowing that the problem was with the NH-CH3 of the hydrophobic emamectin molecule interacting with the Si-OH in the HPLC columns, I started looking for alternatives to silica-based chromatography. That was when I found the ZirChrom web site and read about their zirconia-based PBD column. We purchased an analytical ZirChrom-PBD column, and I was really impressed by the improvement that it made in my chromatography. Although the concept of "tunable selectivity" was new to me, I soon found a system using an ammonium phosphate buffer that gave rapid resolution of the emamectin and sharp, symmetric peaks. Load testing revealed that this column could handle much higher amounts of emamectin than any silica-based column that I had worked with and still give baseline resolution. With the success that we saw with the analytical column, we asked if a preparative HPLC column could be packed with the same 3µm particles. We wanted a column that was the same length as the analytical column (150 mm), but with a larger i.d. so that developed methods could be scaled up directly. Our goal was to find an efficient purification method for synthesized radio labeled emamectin. After working closely with ZirChrom technical support, we ordered a 150 mm x 22 mm i.d. preparative column along with the recommended guard column. The performance of the preparative column was even better than I had expected. We had hoped to be able to run about 10 mg of crude emamectin per injection, but I found that the column could still give baseline resolution when injecting as much as 25 mg. Our original method used a silica-based phenyl column and a multi-step solvent gradient. Using the phenyl column, we could purify 10 mg per run, and each run took 2 ½ hours. With the preparative ZirChrom-PBD column under isocratic conditions, I was able to purify 25 mg of crude emamectin in 30 minutes. The time required to purify 300 mg of crude emamectin was reduced from weeks to a day! David A. Hunt Analytical Chemist Novartis Crop Protection Packed Columns \| Guard Columns \| Application Notes Testimonials