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water is more polar than acetonitrile.but in reverse phase chromatography peaks elute earlier when we increse Acetonitrile.what is the reason.
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Answer / muralikrishna
Even though water is a polar sovent the elution strength of
Acetonitrile is more than water.
| Is This Answer Correct ? | 52 Yes | 12 No |
Answer / michael kwame appenteng
I think it also depends on the constituents of interest, its polarity and whatever parameters you put in place to influence the throughput gradient and resolution. Because in reverse phase chromatography, you have a non-polar (hydrophobic) Stationary phase and a polar aqueous phase (acidified Water as ‘A’ and acidified Acetonitrile as ‘B’). Starting with a higher percentage of the more polar mobile phase (acidified water) will elute the more polar (hydrophilic) constituents, leaving the less polar or hydrophobic constituents adsorbed to the hydrophobic stationary phase. So increasing the percentage of acetonitrile in a way decreases the polarity of the mobile phase so as to elute the less polar or hydrophobic constituents. So once again if your constituents are more hydrophobic or less polar and all other parameters are set right, it works fine.
| Is This Answer Correct ? | 15 Yes | 0 No |
Answer / ronda.venki
based on polarity of stationary phase and sample, normally
reverse phase columns having stationary phase non polar so
ACN INCREASE means elution strength increased bcz of
interactions of stationary phase and product
| Is This Answer Correct ? | 16 Yes | 2 No |
Answer / paresh jobanputtra, piramal(ah
Actually What happen,When we mix Acetonitrile with buffer then VISCOSITY is decresed of mobile phase.
"As viscosity decreased, Mass transfer of solute particle with stationary phase is decreased"
So but obvious component elute earlier.
Regards,
Paresh Jobanputtra
| Is This Answer Correct ? | 7 Yes | 3 No |
Answer / prashant
It based on affinity of eluting substance with stationary phase/mobile phase.if compound elute earlier when we increase ACN obviously compound has more affinity with ACN (towards nonpolar) so it breaks wonderwal bonds with stationary phase and elute earlier
| Is This Answer Correct ? | 2 Yes | 0 No |
Answer / pankaj rabadia
As per the Vandemeter equition as the viscosity of mobile phase is decreased then mass transfer of the solute will incresed, and it will move faster in column n eluted faster... water is more polar than ACN.. but viscocity of ACN is much lower than Water..So eluting strenth of ACN is higer than Water.
| Is This Answer Correct ? | 2 Yes | 0 No |
Answer / nisha
water is more polar then acetonitrile so it make bond strongly than acetonitrile with stationary phase so its viscocity is lowered
| Is This Answer Correct ? | 4 Yes | 4 No |
Answer / ram krishna
Due to viscosity region ACN viscosity is low with comprision of Waterloo so ACN is first eluted from the column and peak is detected U cane see in ACN bottle specific gravity is. 0.85
Viscosity _Ragestenet flow in liquid
| Is This Answer Correct ? | 0 Yes | 1 No |
Answer / skreddy
ACN Formula CH3COCN Same as water H2O COMPARE TO HYDROGEN
ACETO GROUP IS MORE ELECTROPOSSITIVE SO THAT IT RELEASES OH
EARLIER THAN THAT H THAT IT COMES FIRST THAN WATER
| Is This Answer Correct ? | 4 Yes | 20 No |
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