Inspire Diol columns are suitable for RP, NP, and HILIC modes. They are less polar than unmodified silica and very easily wettable with water. The water-enriched layer on the surface facilitates the retention of polar compounds. A well-known use of Diol columns, under normal phase conditions, is the separation of steroids and sterols.

Features of Inspire™ Diol Columns

•  Monomerically bonded dihydroxypropyl group
•  Ultra pure silica and unique bonding chemistry promote long column lifetime, excellent column reproducibility and high inertness without endcapping
•  Unique selectivity for polar/hydrophilic compounds in RP, NP, and HILIC modes
•  Lower polarity than unmodified silica and very easily wettable with water
•  Higher retentivity than silica in NP mode and useful tool as preparative column owing to easy dry-up

Inspire™ Diol Material  Characteristics

HPLC Column Care Instructions

- Dropping or otherwise "shocking" columns can disrupt the column bed and cause peak splitting. 
- Use of eluents in the PH range of 1-11 will maximize column life. 
- The lower the operating pressure, the longer the operating life. 

HPLC packings are subject to a rigorous array of QC tests in a ISO9001 compliant facility, with special emphasis on reagent purity, raw material traceability, and consistency in raw materials and finished products. A detailed analysis of all physical properties, chemical purity, chromatographic selectivity, and column packing efficiency is used to confirm that each lot of column is identical to all previous lots.

We know how important column consistency is to your work, so Dikma Technologies goes to great lengths to make certain that every HPLC column we ship to our customers is of the highest quality possible.

When you receive an HPLC Column from Dikma Technologies, please take the following simple steps:
(1) Check the column for signs of physical damage which may have occurred during shipping. Contact Dikma Technologies immediately to report any problems.
(2) Make sure that the column you received is the column that you ordered.
(3) Take note of the solvent contained in the column during shipping.  (The solvent used for shipping is the same as that used as the mobile phase on the QC test chromatogram ). Before attempting to change solvents, make certain that the eluent you will be introducing into the column is completely miscible with the eluent contained in the column, to avoid precipitation of buffer salts or other mobile phase additives. 
(4) Test the column to verify column efficiency and back pressure (using one of the later-eluting components of the QC test sample).  Contact Dikma Technologies immediately to report any problems.

There are several important things about your analytical method that will greatly affect column life and column performance, including sample preparation, solvent selection, and solvent preparation.
 
Sample Preparation
Non-ideal chemical and physical interaction of samples with the column frits and column packings is a primary source of problems.  Most columns fail because the frit becomes clogged or the stationary phase at the head of the column becomes contaminated.

Samples should be filtered prior to injection.  Even sample solutions which appear to be particulate-free can contain small solids which can clog the pores of the column inlet frit. Samples should be filtered through a 0.45µm or 0.2µm syringe filter before injection.

In addition to filtering samples, Guard cartridges can be used to trap "problems" before they reach the analytical column.  Guard cartridges are essentially tiny HPLC columns that are cheaper to replace than the analytical column.  Please contact Dikma Technologies of Ordering information for guard cartridges.
 
Solvent Selection
Columns last longest when they are used with benign eluents.  Using eluents of high PH or low PH can dissolve silica or catalyze hydrolysis of the bonded phase.  Try to stay within the PH range of 1 - 11 on the columns.  If you must use a PH outside this range, column life might be reduced.
 
Solvent Preparation
Use a 0.45 µm or 0.2 µm filter for solvents as well as samples, even HPLC grade solvents! 
 
Column storage
Column storage conditions can have a profound effect on column lifetime and performance-after-storage. Before extended storage (e.g. greater than 2 days), rinse the column COMPLETELY free of eluents containing buffers, ion-pair reagents, or inorganic solutes, by flushing with 20-50 column volumes of the eluent without the dissolved additives.  Then flush the column with 5-10 column volumes of water (reverse phase columns only).  Then flush the column with 20 volumes of storage solvent (shown above)

                             
In-Situ Column Cleaning
Columns that become fouled over time can sometimes be rejuvenated with an aggressive rinsing sequence, as shown below. In all cases, reverse the column (e.g. attach the outlet end of the column to the pump, and pump the eluent directly into a waste reservoir) and flush the column with 50ml volumes of the indicated solvents in the indicated sequences:

* If mobile phase contains a buffer, flush the column with the mobile phase MINUS the buffer first, to avoid precipitation of the buffer in the pure MeOH remaining in the column.