The COSMOSIL 5C18-MS-II column, taking advantage of a new end capping treatment can replace the COSMOSIL 5C18-MS. The silica gel is end capped with polar groups for shielding effect, based on the chemical property of the packed silica gel to draw highly polar components from the mobile phase. As a result, the new end capping provides improved peak shape for basic compounds. The absorption of the silica gel is controlled because it does not interact with N atoms, therefore suitable for the separation of chelating compounds. Another advantage is that the 5C18-MS-II has similar retention characteristics to the 5C18-MS series: the HPLC conditions for the 5C18-MS are applicable to the newly developed column, 5C18-MS-II.

Stability under alkaline condition

The durability under extremely high pH is greatly improved at the new COSMOSIL 5C₁₈-MS-II compared with current COSMOSIL 5C₁₈-MS. Though it is possible to use under alkaline condition for a limited time, after long exposure some deterioration may occur. For long use we recommend pH 7.5 and below.

Method: After the indicated length of incubation with the extremely high pH buffer, the column was washed and the effective plate number (N) for n-amylbenzene was measured.
The figure above shows the change in N as a function of incubation time. There is hardly any observed change in MS-II. On the other hand with MS when 10 hours or more passed rapid deterioration was observed.
Alkaline solution;0.02M phosphate buffer (pH10.0)

Cosmosil 5C18-MS-II Column

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