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.


Material characteristics
 COSMOSIL® 5C18-MS-II
Silica gel high purity porous spherical silica
Average particle size 5µm
Average pore size approx. 120Å
Specific surface area approx. 300m2/g
Stationary phase monomeric type octadecyl group
End capping treatment near-perfect treatment
Carbon content approx. 16%


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.
Stability under alkaline condition
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)

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COSMOSIL MS-II / AR-II / PAQ (PDF file)


Ordering Information

Product name Size Code No. End-fitting
COSMOSIL® 5C18-MS-II Guard Column 4.6mmI.D.x 10mm 38014-31 Waters type
4.6mmI.D x 10mm
Cartridge (contains 3 guard)		 38015-89
10.0mmI.D.x 20mm 38016-11
20.0mmI.D x 20mm 05790-81
20.0mmI.D.x 50mm 34371-71
28.0mmI.D.x 50mm 34347-01
COSMOSIL® 5C18-MS-II Packed Column 1.0mmI.D.x 50mm 02824-31
1.0mmI.D.x 150mm 02896-01
2.0mmI.D.x 30mm 05876-71
2.0mmI.D.x 50mm 04355-21
2.0mmI.D.x 100mm 05597-31
2.0mmI.D.x 150mm 38025-91
2.0mmI.D.x 250mm 05761-61
3.0mmI.D.x 100mm 05458-51
3.0mmI.D.x 150mm 34245-31
3.0mmI.D.x 250mm 34254-11
4.6mmI.D.x 30mm 34341-61
4.6mmI.D.x 50mm 38017-01
4.6mmI.D.x 100mm 38018-91
4.6mmI.D.x 150mm 38019-81
4.6mmI.D.x 250mm 38020-41
6.0mmI.D.x 150mm 38021-31
6.0mmI.D.x 250mm 38022-21
10.0mmI.D.x 50mm 05789-21
10.0mmI.D.x 150mm 34355-91
10.0mmI.D.x 250mm 38023-11
20.0mmI.D.x 150mm 05091-41
20.0mmI.D.x 250mm 38024-01
28.0mmI.D.x 250mm 05760-71


 
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