|A.) Quality control of bulk-material:
A.) Quality control of bulk-material
B.) Quality control of column packing
C.) Typical HPLC-Test Chromatogram of Dr. Maisch Column (not yet available)
D.) Comparison of theoretical Plate Numbers N
|In order to offer our customers only the best quality of HPLC-columns, we produce all our silica gels:
-ReproSil 100 + 300
under the Quality Control System ISO 9001.
To achieve this purpose, all our products are submitted to the same standard test.
The most common tests are shown below:
Complete Endcapping: Pyridine/Phenol test
The Pyridine /Phenol test provides an ideal test for residual silanol groups. The less silanol groups there are on the silica particles, the earlier the Pyridine elutes in relation to Phenol. On good endcapped phases with high purity silicas, like on ReproSil-Pur ODS-3 (150 x 3 mm),the Pyridine elutes before Phenol.
Eluent: ACN /H20 (40 /60)
Flow rate: 0,25 ml/min.
Tailing of the Acetylacetone peak and Dihydroxyanthraquinone peak are indicators of rest metals on the surface of the silica particles.
With ReproSil-Pur ODS-3 there is no peak-tailing at all.
This prooves the very high purity >99,999%
of the ReproSil-Pur silicas.
(Test conditions: 20mM K-phosphate buffer pH7.5 / MeOH (30/70)
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