HPLC colums

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Venugopal Narne
Venugopal Narne's picture
HPLC colums

I am using a HPLC method with colum X-terra RP 18 150 X 4.6 mm 3.5 mic,
Is it possible to replace this colum with RP 18 250 X 4.6 mm 5 mic.

What is the importance of void spaces in RP-HPLC columns and what is the difference between 3.5mic and 5mic.

Rajiv Dua
Rajiv Dua's picture
Dear Vgnarne...plz note this.

Dear Vgnarne...plz note this...if ur molecule is small then go for 3micron...else u can use 5

Pore Size:
Since the majority of the surface area contained inside the pores, pores must be large enough to provide access to the interior of pores.
Large molecules require large pores, small molecules do not require large pores.
• Smaller pore size particles have higher surface area which increases mass loading capacity of the column.

Particle Size:
Efficiency is higher with smaller particles because they pack together more densely than larger particles thereby increasing number of theoretical plates.
A column packed with 3µm particles will typically have about 1.5 times more efficiency than 5 µm particles.

with regards,