Which of the given serve as a limitations of GC that can be satisfied using SFC?

Which of the given serve as a limitations of GC that can be satisfied using SFC?

Which of the given serve as a limitations of GC that can be satisfied using SFC?

The advantage that SFC has over gas chromatography (GC) is that SFC can efficiently separate thermally labile compounds. The disadvantage of SFC is that the polarity of the mobile phase is limited. Highly polar solutes are not soluble in supercritical fluids, even when modifiers are added.

Which one of the following is an absorption detector used in SFC?

An ultraviolet detector with a capillary flow cell is evaluated for use as a refractive index detector in supercritical fluid chromatography (SFC) using a C O 2 mobile phase. The temperature or pressure control or both of the cell is critical to minimize density-related refractive index changes.

What types of compounds are usually separated by SCF chromatography?

Supercritical fluid chromatography (SFC) is a separation technique based on the use of supercritical fluid, mostly CO2, in combination with one or more polar organic solvents, especially alcohols, used as mobile phase.

What is the longest column used in SFC?

Because supercritical fluids have low viscosities the analysis is faster, there is a much lower pressure drop across the column, and open tubular columns can be used. Shorter column lengths are needed (10-20 m for SFC versus 15-60 m for HPLC) due to the high diffusivity of the supercritical fluid.

Which compounds can be detected by SFC?

A rule-of-thumb is that any molecule that will dissolve in methanol or a less polar solvent is compatible with SFC, including polar solutes. CO2 has polarity similar to n-heptane at its critical point, but the solvent strength can be increased by increasing density or using a polar cosolvent.

Which compounds can be detected by GC?

A broad range of Volatile Organic Compounds (VOC) can be detected with a GC-MS-analysis, e.g.: hydrocarbons (aromatic, aliphatic, cyclic), alcohols, ketones, aldehydes, esters, ethers, furans, organic acids, organic sulphur compounds (dimethylsulphide, dimethyldisulphide, …, thiols), chlorinated compounds, nitrogen ...

What are the 2 phases of chromatography?

Chromatography is a physico-chemical method for separation of compound mixtures, based on the distribution of components between two phases, one of which is stationary (sorbent), and the other, mobile, flowing through a layer of the stationary phase.

Can a GC detect compounds below 250 degC?

Moreover you can analyse by GC-FID only compounds containing carbon atoms. You have to derivatise your compound to make products which have lower boiling point. All compound below 250 deg C can be detected by GC. We have to select non polar capillary columns for it. These column can operate upto 300 deg C.

Which is better GC or supercritical fluid chromatography?

SFC has several advantages over GC and HPLC: it extends the molecular-weight range of GC, thermally labile compounds can be separated at lower temperatures, compounds without chromophores can be sensitively detected, and the use of open-tubular and packed columns is feasible.

Which is better, a GC or a SFC?

SFC has several advantages over GC and HPLC: it extends the molecular-weight range of GC, thermally labile compounds can be separated at lower temperatures, compounds without chromophores can be sensitively detected, and the use of open-tubular and packed columns is feasible. Figure 7 shows a schematic layout of a SFC system. Figure 6.

Can a sugar molecule be detected by GC?

Molecules such as sugars and amino acids can not be easily analyzed by GC because of the large number of polar groups. Inorganic compounds are not suitable for GC analysis. But most organic compounds are suitable for GC analysis. Anything that will burn other than hydrogen will be detected. Even fluorocarbons can be detected

Related Posts: