Are all C18 columns the same?

Are all C18 columns the same?

The different C18 columns are made to allow for different selectivities. Although all your columns are C18 functionalized phases, they will differ in hydrophobicity, peak shape (depending of degree and quality of end-capping and purity of silica) and selectivity and perhaps pore radius.

What is C18 in chromatography?

C18 columns are HPLC (high performance liquid chromatography) columns that use a C18 substance as the stationary phase. C18 simply means that the molecules contain 18 carbon atoms, so the other atoms in the molecule can vary, leading to significantly different substances.

What is difference between C8 and C18 column?

C18 has 18 carbon atoms while C8 has only 8 carbon atoms. C18 has a longer carbon chain, but C8 has a shorter one. C18 has higher retention while C8 has shorter retention. C18 has higher hydrophobicity, but C8 has a lower hydrophobicity.

How are the elements in the same column similar?

Representative elements that are found in the same column of the periodic table have the same number of valence electrons. Valence electrons are the electrons that are located in the outermost energy level of an atom. When chemical bonds are formed, the valence electrons in atoms are gained, lost, or shared.

Is C18 normal phase?

Hydrophobic Stationary Phase More specifically, straight-chain alkanes are well-suited to serve as a good stationary phase. We should note that as the carbon atoms in the chain increases, the physical properties of the hydrocarbon changes as well—C1 through C4 are gaseous; C5-C17 are liquid; C18 and larger are solids.

Is C18 column reverse phase?

A C18 column is an example of a “reverse phase” column. Reverse phase columns are often used with more polar solvents such as water, methanol or acetonitrile. The stationary phase is a nonpolar hydrocarbon, whereas the mobile phase is a polar liquid.

Is C18 reverse phase?

Is C18 polar or nonpolar?

What is the difference between ODS and BDS column?

ODS and BDS are two columns used for reverse-phase chromatography. The key difference between ODS and BDS column is that ODS column contains free –OH functional groups, whereas BDS column contains deactivated –OH groups. Moreover, ODS columns have high peak tailing while BDS columns are designed to reduce peak tailing.

What is the structure of C18 column?

YMC-Triart C18 is a multi-layer hybrid particle consisting of two types of layers: a silica based layer (inorganic) and a hybrid polymer based layer (organic). This layered structure contributes to Triart’s combined physical durability and chromatographic performance.

What’s the difference between a C18 and C8 column?

In other terms, C18 has Octadecyl chains which are usually hydrophobic and highly retain nonpolar compounds. The length of its carbon chain is longer. On the contrary, C8 has Octyl chains and hence it is less retained when used with the same compound as C18.

How are C18 and C8 columns chosen in HPLC?

Alltech has developed a method for choosing C18 and C8 columns based on peak capacities and column selectivity of polar and nonpolar compounds. Typically chromatographers must choose HPLC columns by comparing the surface area and carbon load data supplied by the column manufacturers.

How are C18 columns used in liquid chromatography?

C18 columns are HPLC (high performance liquid chromatography) columns that use a C18 substance as the stationary phase. C18 HPLC columns are used in environmental sciences and chemical analysis, as well as industries such as pharmaceutical and environmental sciences, to analyze individual parts of chemical mixtures.

What is the flow rate of a C18 column?

Acclaim™ Carbonyl C18 LC Column 1 Mode of Separation: Speciality / Application Specific 2 Packing Material: Spherical, fully porous ultrapure silica 3 End Capping: Yes 4 Flow Rate: 0.25 to 0.75mL/min.