Lasercrhom HPLC - Shodex Polymer Based Reverse Phase Columns

Shodex Polymer-Based Reversed Phase HPLC Columns

Polymer-based reverse phase (RP) columns are usually more expensive than silica-based columns , so there needs to be good reasons for using them. These reasons include: They are stable over a much wider pH range (2-12). So for any application that requires a high pH either to get sharp peaks (ie basic compounds) or to clean the columns between runs then this is the best choice. They last longer. A column "dies" when the packing dissolves , or the bed blocks up, or the bonded phase strips off , or it becomes contaminated and cannot be cleaned. Polymer based packings do not dissolve even at high pH, the bonded phase of a polymer column is usually stable and the column can be cleaned with agressive solvents. So if these are the reasons why your columns are being thrown away, a polymer column may last much longer . Column to column reproducibility is better. Thus making method validation simpler.

It used to be true that silica columns gave sharper peaks, but not any more! See the new ODP2 HPcolumns below! Polymer RP columns offer a wide choice of selectivity. Most polymers used have non-polar chracteristics and so can be used underivatised (like silica is for normal phase separations). These non-polar polymers give slightly different selectivity from conventional ODS columns, so are complimented by a range of RP columns with an ODS chain bonded to the polymer (See ODP columns below).

Other features to note are:
Pore Size	The bigger the pore size the wider the range of molecular weight species that can be analysed, but the lower the maximum back pressure the column can withstand.
Particle Size	Typically 3-10 μm, similar to silica columns
Efficiency	Some polymer columns give sharper peaks than others
Solvent Range	Some columns are damaged by 100% water. Most are damaged by >0.5M buffer.
pH Range	Much wider than silica, but please note there are still boundaries.
Temp Range	Varies depending on polymer
Max Pressure	Some polymers can take more back pressure than others so check the maximum and do not exceed it.
More information is available below or at the Shodex website www.shodex.com

Free sample trial analysis and column comparison in our lab!
The biggest differences in selectivity occur between four of the columns below: DE, RP18, ODP40 and the brand new ODP2 HP. We have these columns set up in our lab, and would be pleased to run a comparative analysis of your sample on each of these columns for you at no charge and with no obligation to buy. if we find that a small eluent change would help with a particular column we will make the change and send you a set of four chromatograms so that you can see which column offers the best selectivity! To arrange this, please call us on +44(0)1634 294001. We will need a sample (ready for injection) and the method that you currently use.
Column Details

Packing	Polymer	Particle Size (μm)	Pore Size (A)	Efficiency (N/m)	Functional Group	pH Range	Temp Range (oC)	Solvent Range (MeOH, MeCN, Water)	Max. Pressure (psi)
ODP2 HP (NEW!)	Polyhydroxymethacrylate	5	40	80,000	none	2-12	RT-60	Any	2250
This material was launched on 14th September 2006, and is designed to be a direct alternative to silica-based C18 columns. Not only is it high efficiency, with all the benefits of a polymer column, but is it priced to compete directly with silica columns! Because of the low pore size, materials such as proteins are totally excluded from the column, making it ideal for analysis of drugs in the presence of proteins. It does however mean that the maximum molecular weight that can be analysed is about 800. Call us to discuss possible applications. For pricing and ordering information click here, or for more info click here.
DE	Polymethacrylate	4	100	70,000	none	2-12	RT-60	Any	2250
This is a good general RP column, with characteristics very similar to a silica based C18 column. Can use any combination of solvents, but keep the pressure below 2000 psi. Maximum flow rate is 1.2ml/min with a 4.6mm ID column. For pricing and ordering information click here, or for more info see www.shodex.com
DS	Styrene Divinyl Benzene Co-polymer	3.5	100	70,000	None	2-13	RT-80	90% Water maximum	3000
These columns will give retention to hydrophilic substances which are hard to retain on normal C18 columns. It has a wider pH range than the DE column but must not be used with 100% water because it causes the gel to swell. Maximum flow rate is 1.0ml/min with a 4.6mm ID column. For pricing and ordering information click here, or for more info see www.shodex.com
RP18-413 RP18-613	Styrene Divinyl Benzene Co-polymer	3.5	100	80,000	None	1-13	RT-50	90% Water maximum	3300
A higher efficency version of the DS column . It can take slightly higher pressure but a slightly lower temperature. Again it must not be used with 100% water. For pricing and ordering information click here, or for more info see www.shodex.com
RP18-415	Styrene Divinyl Benzene Co-polymer	6	430	36,000	None	1-13	RT-50	Any	3300
This is a wide pore size version of the RP18 column for use with proteins and peptides For pricing and ordering information click here, or for more info see www.shodex.com
Asahipak ODP	Polyvinyl Alcohol	5	250	56,000	C18	2-13	4-60	Any	2250
Has a conventional C18 chain bonded onto the polymer, so gives a selectivity very similar to a conventional silica based C18 column, but with no polar silanol sites. It has a 17% carbon loading. Maximum flow rate is 2.5ml/min with a 4.6mm ID column. For pricing and ordering information click here, or for more info see www.shodex.com
Asahipak ODP40	Polyvinyl Alcohol	4	250	68,000	C18	2-13	4-60	Any	1950
The same as the Asahipak ODP , but with smaller particle size and therefore a correspondingly higher efficeiency. For pricing and ordering information click here, or for more info see www.shodex.com
Asahipak C8P	Polyvinyl Alcohol	5	250	45,000	C8	2-13	4-60	Any	2250
The same as Asahipak ODP, but with a C8 chain instead of a C18, and a 10% carbon loading. Gives very similar separation to a silica based C8 column but without the pH limitations. For pricing and ordering information click here, or for more info see www.shodex.com
Asahipak C4P	Polyvinyl Alcohol	5	250	40,000	C4	2-13	4-60	Any	2250
The same as the Asahipak C8P but with a C4 chain instead of a C8 chain and a carbon loading of 6%. For pricing and ordering information click here, or for more info see www.shodex.com
NN	Polyhydroxymethylacrylate	10	100	40,000	none	2-12	10-50	Any	2250
The polyhydroxymethacrylate polymer contains a trace of sulfo groups, giving a mixed mode separation. This material is capable of separating acidic, neutral and basic substances and hence is recommended for complex mixtures. For pricing and ordering information click here, or for more info see www.shodex.com
JJ	Polyvinyl Alcohol	5	100	32,000	none	2-110	10-60	Any	1400
This polyvinyl alcohol polymer contains a trace of quarternary ammonium groups, giving a mixed mode separation. This material is capable of separating acidic, neutral and basic substances and hence is recommended for complex mixtures. The maximum flow rate is 1.2ml/min in a 4.6mm id column. For pricing and ordering information click here, or for more info see www.shodex.com