Due to the highly sophisticated production process YMC’s highly spherical silica material shows premium performance and great lot-to-lot reproducibility. The reason for this can be summarised in two main qualities: the very narrow physical and chemical product specifications and the outstanding purity.

YMC Pack PVA-Sil, which possesses a polyvinyl alcohol (PVA) surface chemistry, is an excellent alternative to silica gel or other polar bonded normal phases. The polymerised PVA completely covers both external and internal surfaces of the silica support, protecting it against aggressive, high pH buffers and solvents.

In many situations it exhibits better performance characteristics and a unique selectivity and can often resolve compounds that behave poorly on silica. The alcohol functionality present on YMC Pack PVA-Sil is better suited for troublesome compounds, such organic bases, than acidic silanols present in nonbonded silica.

The unique cyano chemistry of YMC-Pack Cyano provides a different selectivity from both phenyl and standard aliphatic (C18, C8 or C4) reversed phase packings. Cyano packings also provide an alternative to silica material in normal phase chromatography, where bonded normal phase packings have the advantage of faster equilibration, more uniform surface activity and increased resistance to dissolution. 

Normal phase cyano columns can be switched to reversed phase solvents but not vice versa due to the water in reversed phase solvents wetting the silica surface and making re-equilibration under normal phase conditions impossible.

In normal phase mode the YMC-Pack Diol stationary phase is a versatile alternative to silica. The bonded phase’s hydroxyl groups provide good selectivity without excessive retention, since hydrogen bonding with the diol layer is not as strong as with the silanols on a non bonded silica surface. YMC Pack-Diol also provides improved reproducibility when compared with bare silica.

Diol packings are suitable for separations using reversed phase techniques or molecular weight determination of proteins by gel filtration, but whilst normal phase diol columns can be switched to reversed phase solvents the reverse is not true due to the water in reversed phase solvents wetting the silica surface and making re-equilibration under normal phase conditions impossible.

YMC-Pack Polyamine II stationary phase functionality is achieved by a covalently bonded polymer layer containing both secondary (2°) and tertiary (3°) amino groups. The low reactivity of the 2° and 3° amino groups preserves the long-term retention characteristics and selectivity of YMC-Pack Polyamine II. Compared to conventional amino phases, one of its most outstanding benefits is the significantly prolonged lifetime often due to the inability to form Schiff’s bases.

Reducing sugars are often adsorbed irreversibly to conventional amino phases. This causes problems in recovery and quantitation. With YMC-Pack Polyamine II columns however, the adsorption of reducing sugars is very low because no Schiff’s bases can be formed. As a result, high recovery of these compounds can be obtained which is beneficial for accurate and reliable quantitation.

YMC-Pack Amino is frequently used for the analysis of mono-, oligo- and polysaccharides (but see YMC-Pack Polyamine II) under aggressive normal phase elution conditions. The amine functionality provides retention and allows the separation of polar compounds under aggressive normal phase elution conditions, e.g. the analysis of saccharides using acetonitrile/water eluents.

YMC-Pack Amino can also be used for the separation of isomers of tocopherols and other organic soluble compounds such as paraffins, olefins and aromatics under conventional normal phase conditions. In aqueous, low pH buffers the amino phase becomes a weak anion exchanger capable of separating negatively charged molecules.

YMC-Pack C1 is bonded with trimethylmonochlorosilane to create a phase with intermediate polarity for separation of extremely hydrophobic compounds using conventional reversed phase solvents and of highly polar compounds using normal phase solvents. The unique chemistry of TMS is also well-suited for the analysis of multifunctional compounds. Selectivity characteristics of a C1 bonded phase can be unique, and samples must be tested to determine the applicability of the phase.