what is the difference between c-8 and c-18 column
Answers were Sorted based on User's Feedback
In chromatography silanol groups (Si-OH) at the
surface of silica gel are reacted with substituted Chloro
Silanes.
CH3 CH3
| | | |
--Si–OH + Cl - Si--R → --Si-O - Si - R
| | | |
CH3 CH3
By changing characteristics of group i.e. from changing R
from C1 to C18 we can alter the nature of stationary phase
from polar to non polar. Since C18 columns is non polar.
This helps separating various combinations of polar – non
polar constituents from the analyte.
C-8 columns contain 8 carbons and C-18 contains 18
carbons are attached to silicon group to form stationary
phases for chromatography. The C-18 columns are highly
Non polar compared to C-8 columns and most of the compounds
are well separated in C-18 carbon packed columns.
| Is This Answer Correct ? | 14 Yes | 2 No |
Answer / kumar nagendra karapala
C-8 means having 8 carbons and C-18 (ODS) means having 18
carbons both are attached to silicaon groups to from
stationary phases for Chromatography.
| Is This Answer Correct ? | 13 Yes | 3 No |
Answer / srikanth
C18 column is more hydrophobic than C8.
Because, The difference between the two columns will be in
the length of the carbon-chain attached to the silica
surface. Acoordingly C8 hplc columns have packing material
composed of silica particles attached to C8 carbon units
while C18 will, of course, have packing materials coated
with C18 hydrophobic units. Categorically both are reversed
phase but C18 columns will definitely be more "hydrophobic
rather than the C8 columns.
| Is This Answer Correct ? | 7 Yes | 1 No |
Answer / s.goutham
the c18 coloumn wsa highly non polar compared to c8
coloumn.Most of the compound well seperated in c18
| Is This Answer Correct ? | 5 Yes | 1 No |
WHAT IS DIFFERENCE B/W MALTINGRANG/DSC
In the test for control of absorbance in UV calibration why do we use only potassium dichromate and what is purpose of taking a specified amount of 57.0-63.0mg?
8 Answers Aurobindo, Cipla, FDC,
What are the concentration limit for class-1 residual solvents in ICH ?
What is the formula to determine the concentration of M of a solution given the % transmittance? Use %T = 43.7 as an example.
WHY KBr is used in IR Spectroscopy
How to Prepare Dilute Sodium hydroxide solution?
why plane of polarized light rotated by opticaly active compunds?
In Assy by potentio metry titration method how select MET U ,DET U, SET U,
why water factor is near about 5.0 in kf titration?
3 Answers Claris Lifesciences, Indchemie Health Specialities,
WHAT IS PVT TEST IN DISSOLUTION TEST , WHAT IS PVT SIGNIFICANCE AND HOW IT IS PERFORMED ?
(0.41)d what is d?
in which situation require to change rs specification?