Certain criteria play a big role in selecting a suitable GC column for applications in the laboratory. This includes the column length, the internal diameter of the column, the chemical phase and the thickness of the coating. The description of a GC product is for example as follows: GC column TG-BOND Q 15m x 0.32 mm x 10 µm. This describes the Thermo Fisher Scientific GC column of the product line TG-BOND Q with a column length of 15 meters, an internal diameter of 0.32 millimeters and a coating thickness of 10 microns.
Thermo divides the GC columns into different subgroups by their polarity. For low-to-medium-polarity columns, Thermo offers a range of product lines: while TRACE ™ TR columns consist of cyanopropylphenyl-polysiloxane, the stationary phase of TRACE ™ TR-V1 is a column of cyanopropylphenyl polysiloxanes. Both are columns with medium polarity. These are recommended for the application of pesticides, organic acids, steroids or drugs.
The TRACE ™ Gold TG product line has a slightly polar character due to the mixed composition of the stationary phase from a small proportion of cyanopropylphenyl and a high proportion of dimethyl polysiloxane. These columns are used for the determination of alcohols or other volatile compounds, oxygen compounds or solvent residues. TRACE ™ Gold TG-5MS columns with a stationary phase of diphenyl and dimethyl polysiloxane also have a low polar character. However, they are recommended for the analysis of compounds, phenols and amines that are difficult to react.
Thermo Scientific Trace Gold gas chromatography capillary columns with extremely low column bleed offer excellent reproducibility and thus ensure data consistency and a longer column life. The Trace Gold GC columns are extremely inert and ensure a very good peak shape even at very reactive or difficult analytes where often a peak tailing occurs. A lower column bleed minimizes the risk of contamination of the mass spectrometer, thus prolonging the intervals for preventive maintenance. The low baseline noise enables high sensitivity, improved detection limits and (less for analytes concentration) a more optimal resolution. Each column also provides batch to batch consistent quality results, enabling the generation of reliable data for gas chromatography.
Product lines with high polarities are, for example, TRACE ™ TR-FAME, TRACE ™ TR-WAX or TRACE ™ GOLD TG-POLAR. The stationary phase of TRACE ™ TR-FAME columns is cyanopropyl-polysilphenylene-siloxanes, which results in an extreme robustness against high temperatures and a low column bleeding. These columns are particularly suitable for the analysis of fatty acid methyl esters.
TRACE ™ TR-WAX columns consist of highly cross-linked and fully deactivated polyethylene glycol. They are used for the analysis of esters, alcohols, ketones and also aromatic isomers. It is also possible to determine reliable and reproducible results even at high temperatures by low column bleeding.
The highly polar phase of the TRACE ™ GOLD TG-POLAR columns consists of unbound biscyclopropane and phenylcyanopropyl polysiloxane. Due to a strong dipole moment, there is a high selectivity for cis / trans compounds or conjugated double bonds. Accordingly, these columns serve the analysis of cis / trans fatty acid methyl esters or dixoins.