CN, Diol, NH₂-modified Silica Plates

Expand the Possibilities of TLC and HPTLC.

Merck’s modified silica TLC and HPTLC plates offer additional selectivities and significantly broaden thin layer chromatography applications. This makes them the optimal choice for challenging separations that cannot be adequately solved by unmodified silica. Since most substances separated on modified silica plates are colorless, the majority of our plates contain the blue fluorescent, acid-stable UV indicator F₂₅₄s. Samples that absorb shortwave UV at 254 nm are detected due to fluorescence quenching.

CN and Diol-Modified Plates

Normal-Phase and Reversed-Phase Separations

CN and Diol-modified silica plates are moderately polar, and suitable for both normal-phase and reversed-phase systems. The CN-modified plate is based on a silica gel 60 modified with a cyano propyl group, while the Diol-modified plate utilizes a silica surface modified by a vicinal diol alkyl ether. The dual characteristic of the CN plate enables unique two-dimensional separations by using the normal-phase mechanism in the first direction, followed by the reversed-phase mechanism in the second direction.

NH₂-Modified Plates

Excellent Separation of Charged Compounds

Amino-modified NH₂ plates provide weakly basic ion-exchange characteristics with extraordinary selectivity for charged compounds. These unique features enable the separation of compounds such as nucleotides, purins, pyrimidines, phenols and sulfonic acids using simple eluent mixtures. For many applications, NH₂-modified silica plates offer an alternative to PEI cellulose. In addition, they allow reagent-free detection of certain compounds (e.g. carbohydrates) by thermochemical fluorescence activation.

Features and Benefits

• Results are less dependent on atmospheric humidity
• Separation of highly non-polar and polar substances using aqueous solvent systems
• No catalytic activity towards non-stable compounds (e.g. oxidative degradation)

Separation of Oligonucleotides

Plate	HPTLC silica gel 60 NH2 (1.12572)
Sample volume	200 nL
Mobile phase	Ethanol-water (60 : 40 v/v) plus 0.2 mM lithium chloride
Detection	UV 254 nm (TLC/HPTLC Scanner 2)
Compounds	1. ApUpG 2. ApApU 3. ApApC 4. ApApA all 0.1 %