what is the general mechanism of high performance liqiud
chromatography?
Answer Posted / nabil
Confusigly,there are two variants in use in HPLC depending
on the relative polarity of the solvent and the stationary
phase.
1-Normal Phase HPLC
The column is with tiny silica particles, and the solvent
is non polar hexane for example, Polar cpds in the mix
being passed through the column will stick longer to the
polar silica than the non polar cpds will, the non polar
ones will therefore pass more quickly through the column.
2-Reversed phase HPLC
In this case the silica is modified to make it non polar by
attacheing hydrocarbon chains to its surface typically with
either 8 or 18 carbon atomsin them. A polar solvent is used.
In this case there will bestrong attraction between polar
solvents and polar molecules will pass through
thecolumntherewon't be much attractoin between the
hydrocarbon chain and the polar solvent.
Non polar cpds in the mix will tend to form attractions
with the hydrocarbons gps because of van der waals forces
they will be also less soluble in the solvent because the
need to break the hydrogen bonds,they spend less time in
solution in the solvent, that mean the polar molecules that
will travel through the column more quickly.
Is This Answer Correct ? | 4 Yes | 2 No |
Post New Answer View All Answers
What is aggregate and fragments in SEC?
pharma industries oriented
If change in specification which parameter require to do for validation? if change in chromtographic condition then which parameter? if api change then which parameter? if change composition then which parameter? if old method not work out then whicj parameter? if additional one impurity added then which parameter of validation require to do on above each conditions? elaborate separately
Which is the highly polar and highly non polar column in HPLC?
How can I develope method of dissolution by HPLC OR UV
What is Band broading effect explain
in which situation require to change rs specification?
Why acetonitrile and water are used as extraction solvent when analysis melamine? I thought they are miscible and won't be able to separate...
How to decide assay range for non pharmacopeial API analysis by HPLC? Could you give me any reference for same e.g Guidelines or Paper publications?
What is shaking level in GC?
What is the main difference between ODS1 and ODS2 Hplc column.
what is the importance of peak purity in HPLC and how we can calculate through manul(not software)?
How require to perform linearity as per ANVISA? What are the acceptance criteria?
How they found 1mL of K.F reagent is equivalent to 5mg of water and if we change the composition of K.F reagent, is it can neutralize more amount of water?
we are performed SOR for a particular product the limit is -6 to -10.We face particular bathes it is not meeting the specification.we performed diffrent instrument diffrent analyst we are getting diffrent diffrent results.solvent is dimethyl sulfoxide what could be the reasion