Polyaromatic hydrocarbons (PAH's) are large organic compounds produced during combustion. Many of these compounds are carcinogenic and are often found in water, air and other natural habitants. Monitoring of these compounds is very crucial for a healthy environment. The major challenge in HPLC analysis of PAH's is in the resolution of their structurally similar isomers. Figure 1 shows the resolution of 16 PAH's designated as Priority pollutants by the US EPA. SMT PAH1 columns consist of octadecyl functional ligands and are made with silica with proprietary pore size.
Unique features of TNT columns:
- Highly reproducible mixed bonded phase; consistent separation of analytes.
- Increased longevity provided through ?total coverage?.
The column also offers enhanced separation for pesticides, herbicides, pharmaceutical metabolites, polar natural products and other polar bio-molecules.
OD-IQ is unique reversed phase packing material designed to have both hydrophobic and truly hydrophilic spacer ligands. The mixed-phase consists of a meticulously controlled mixture of hydrophobic, C18 molecules, and proprietary hydrophilic molecules, chemically attached on the silica substrate, using ?total coverage? technology. The result is a stationary phase that has all of the following characteristics:
- Stronger retention of polar molecules in aque-ous eluent.
- Reduced backpressure; the hydrophilic hybrid enhances the solvation of the bonded phase in an aqueous environment.
- Different selectivity compared to conventional C18.
- Eliminates the need for ion pairing reagents.
The column offers enhanced separation for proteins, peptides, nucleotides and other bio-molecules. The column is also recommended for the analyses of highly polar organic compounds.
C12 columns consist of Dodecyl as the functional ligand. The columns offer selectivities that are slightly different from C8 and C18 reversed-phase columns when applied to separation of polyaromatic hydrocarbons. C12 columns are specially designed as complementary alternatives for the separation of polar, neutral and moderately nonpolar pharmaceuticals; natural products, food additives, organic chemicals and biologicals.
C30 columns consist of Triacontyl as the functional ligand. The columns offer selectivities that are much different from C18 reversed-phase columns when applied to separation of carotenoid and related compounds. Carotenoids consist of very diverse groups of molecules that include nonpolar hydrocarbons and polar xanthophylls. These compounds have geometric and positional isomers with very subtle molecular differences that can pose challenges in separation. Previous efforts to separate these compounds with available C18 and other reversed phases have been unsatis-factory. C30 ligand provides sufficient in-teractive sites for complete partitioning of these positional isomers.
C6F5 columns consist of Pentafluorophenyl as the functional ligand. The columns offer selectivities that are different from other reversed-phase columns when applied to separation of halogenated compounds, ketones, esters, aromatics, and conjugated systems. Many naturally occurring chemicals also contain polarizable electrons that can be separated using C6F5. C6F5 has been extremely useful in the separation of epimers. Epimers exist in many natural mixtures such as pharmaceutically active natural taxol. Taxol has been approved by the US Food and Drug Administration for treatment of ovarian cancer. C6F5 columns are specially designed for the separation of Taxols. The crude and complex nature of the matrix tend to shorten the column lifetime when traditional reversed-phase columns are used in this application. C6F5 columns are much more suitable alternatives for the separation of these compounds.
A chiral column may contain one form of an enantiomeric compound immobilized on the surface of a packing material. The following is a list of some of the most important features for adequate separation with chiral columns:
- At least three points of simultaneous interaction between the chiral phase and one analyte enantiomer, with at least one point of stereo-chemical dependence.
- One of the enantiomers have differing degrees of interaction with the stationary phase, so that one will be more strongly retained than the other.